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NOBUKAWA Kumiko

    Department of Science　Lecturer
Last Updated :2024/04/13

Researcher Information

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Research Interests

  • Astrophysics   Low-energy cosmic rays   Supernova remnants   Milky Way   x-ray astronomy   

Research Areas

  • Natural sciences / Particle, nuclear, cosmic-ray, and astrophysics - experiment
  • Natural sciences / Astronomy

Academic & Professional Experience

  • 2020/04 - Today  Kindai UniversityFaculty of Science and Engineering Department of ScienceLecturer
  • 2016/04 - 2020/03  Nara Women's UniversityFaculty of ScienceResearch Fellowships for Young Scientists (PD)
  • 2013/04 - 2016/03  Kyoto UniversityGraduate School of ScienceResearch Fellowships for Young Scientists (DC1)

Education

  • 2011/04 - 2016/03  Kyoto University  Graduate School of Science  Department of Physics

Association Memberships

  • High Energy Astrophysics Association in Japan   The Astronomical Society of Japan   International Astronomical Union   THE PHYSICAL SOCIETY OF JAPAN   

Published Papers

  • Asahi Fujishige; Shigeo Yamauchi; Kumiko K Nobukawa; Masayoshi Nobukawa
    Publications of the Astronomical Society of Japan Oxford University Press (OUP) 75 (5) 907 - 912 0004-6264 2023/07 
    Abstract The results of a Suzaku observation of the supernova remnant (SNR) G352.7−0.1 are presented in this paper. We conducted spectral analysis based on careful sky background estimation and found an emission line from Al at 1.6 keV, in addition to previously detected emission lines from Mg, Si, S, Ar, Ca, and Fe ions. The X-ray spectrum in the 0.7–10 keV band is represented by a two-component ionizing plasma model with different temperatures and ionization timescales. Based on the results, properties of the X-ray emitting plasma and the explosion type are discussed.
  • Kumiko Yamamoto; Shigeo Yamauchi; Masayoshi Nobukawa; Kumiko K Nobukawa; Hideki Uchiyama
    Publications of the Astronomical Society of Japan Oxford University Press (OUP) 0004-6264 2023/03 
    Abstract The Galactic ridge X-ray emission (GRXE) is unresolved X-ray emission located on the Galactic plane, and whether the GRXE comes from truly diffuse plasma or unresolved point sources is still debatable. We present results of spectral analysis of the GRXE with Suzaku. In order to examine the point source origin, we fitted the GRXE spectra in the 1.2–10 keV energy band with a point source model, which is a mixture of active binary stars (ABs) and non-magnetic cataclysmic variables (non-mCVs), and found that the model cannot represent the GRXE spectral shape as long as the standard metal abundances of these species are assumed. In particular, the standard abundance model cannot account for the observed intensities of Si, S, and Ar lines as well as the previously reported Fe line. Assuming spatial densities in the solar neighborhood, integration of the ABs and non-mCVs accounts for only 30% of the observed GRXE flux. Other species of the point sources or diffuse emission with stronger Si, S, Ar, and Fe emission lines shall explain the rest.
  • Yuma Aoki; Kumiko Nobukawa; Yamato Ito; Masayoshi Nobukawa; Yoshiaki Kanemaru; Keitaro Miyazaki; Kohei Kusunoki; Koji Mori; Tomokage Yoneyama; Tsubasa Tamba; Hiroshi Tomida; Hiroshi Nakajima; Hironori Matsumoto; Hirofumi Noda; Kiyoshi Hayashida; Hiroyuki Uchida; Takaaki Tanaka; Hiromasa Suzuki; Tessei Yoshida; Hiroshi Murakami; Makoto Yamauchi; Isamu Hatsukade; Kouichi Hagino; Takayoshi Kohmura; Hideki Uchiyama; Kazutaka Yamaoka; Masanobu Ozaki; Tadayasu Dotani; Hiroshi Tsunemi; Kumiko Nobukawa; Takeshi Tsuru; Shogo Kobayashi; Junko Hiraga
    Proceedings of 10th International Workshop on Semiconductor Pixel Detectors for Particles and Imaging — PoS(Pixel2022) Sissa Medialab 2023/03 [Refereed]
  • Rui Himono; Masayoshi Nobukawa; Shigeo Yamauchi; Kumiko K Nobukawa; Nari Suzuki
    Publications of the Astronomical Society of Japan Oxford University Press (OUP) 0004-6264 2023/02 [Refereed]
     
    Abstract We have investigated supernova remnant (SNR) W 28 using Suzaku archival data, and we report here the results of our spatially resolved analyses. We carried out spectral analyses using a recombining-plasma (RP) model with element-dependent initial ionization temperatures, obtaining ∼0.5 keV for Ne, ∼0.7 keV for Mg, ∼1.0 keV for Si, ∼1.2 keV for S, ∼1.4 keV for Ar, ∼1.7 keV for Ca, and ∼0.7 keV for Fe in the initial RP phase. In addition to the north-east regions where RPs have been reported previously, we find that the ionization temperatures in the south-east and south-west regions exhibit trends that are similar to those in the central region in the initial RP phase. We also find that the time elapsed from the initial phase of the RP to the present is shorter in the central region, ∼300 yr, and longer in the outside regions, ∼103–104 yr. Our results cannot be explained by simple scenarios involving thermal conduction into molecular clouds or by adiabatic cooling (due to rarefaction), indicating that more complex mechanisms or other scenarios are required. We also estimate the ejecta mass to be ≳14 M⊙, which indicates that this SNR was produced by a massive star.
  • Kumiko K. Nobukawa; Masayoshi Nobukawa; Shigeo Yamauchi
    Advances in Space Research Elsevier BV 0273-1177 2022/09 [Refereed]
  • Koji Mori; Takeshi G. Tsuru; Kazuhiro Nakazawa; Yoshihiro Ueda; Shin Watanabe; Takaaki Tanaka; Manabu Ishida; Hironori Matsumoto; Hisamitsu Awaki; Hiroshi Murakami; Masayoshi Nobukawa; Ayaki Takeda; Yasushi Fukazawa; Hiroshi Tsunemi; Tadayuki Takahashi; Ann E. Hornschemeier; Takashi Okajima; William W. Zhang; Brian J. Williams; Tonia Venters; Kristin Madsen; Mihoko Yukita; Hiroki Akamatsu; Aya Bamba; Teruaki Enoto; Yutaka Fujita; Akihiro Furuzawa; Kouichi Hagino; Kosei Ishimura; Masayuki Itoh; Tetsu Kitayama; Shogo B. Kobayashi; Takayoshi Kohmura; Aya Kubota; Misaki Mizumoto; Tsunefumi Mizuno; Hiroshi Nakajima; Kumiko K. Nobukawa; Hirofumi Noda; Hirokazu Odaka; Naomi Ota; Toshiki Sato; Megumi Shidatsu; Hiromasa Suzuki; Hiromitsu Takahashi; Atsushi Tanimoto; Yukikatsu Terada; Yuichi Terashima; Hiroyuki Uchida; Yasunobu Uchiyama; Hiroya Yamaguchi; Yoichi Yatsu
    Space Telescopes and Instrumentation 2022: Ultraviolet to Gamma Ray SPIE 12181 1218122  2022/08
  • Koji Mori; Hiroshi Tomida; Hiroshi Nakajima; Takashi Okajima; Hirofumi Noda; Takaaki Tanaka; Hiroyuki Uchida; Kouichi Hagino; Shogo B. Kobayashi; Hiromasa Suzuki; Tessei Yoshida; Hiroshi Murakami; Hideki Uchiyama; Masayoshi Nobukawa; Kumiko K. Nobukawa; Tomokage Yoneyama; Hironori Matsumoto; Takeshi G. Tsuru; Makoto Yamauchi; Isamu Hatsukade; Manabu Ishida; Yoshitomo Maeda; Takayuki Hayashi; Keisuke Tamura; Rozenn Boissay-Malaquin; Toshiki Sato; Junko Hiraga; Takayoshi Kohmura; Kazutaka Yamaoka; Tadayasu Dotani; Masanobu Ozaki; Hiroshi Tsunemi; Yoshiaki Kanemaru; Jin Sato; Toshiyuki Takaki; Yuta Terada; Keitaro Miyazaki; Kohei Kusunoki; Yoshinori Otsuka; Haruhiko Yokosu; Wakana Yonemaru; Yoh Asahina; Kazunori Asakura; Marina Yoshimoto; Yuichi Ode; Junya Sato; Tomohiko Hakamata; Mio Aoyagi; Yuma Aoki; Shun Tsunomachi; Toshiki Doi; Daiki Aoki; Kaito Fujisawa; Masatoshi Kitajima; Kiyoshi Hayashida
    Space Telescopes and Instrumentation 2022: Ultraviolet to Gamma Ray SPIE 12181 0277-786X 2022/08 
    Xtend is a soft x-ray imaging telescope developed for the x-ray imaging and spectroscopy mission (XRISM). XRISM is scheduled to be launched in the Japanese fiscal year 2022. Xtend consists of the soft x-ray imager (SXI), an x-ray CCD camera, and the x-ray mirror assembly (XMA), a thin-foil-nested conically approximated Wolter-I optics. The SXI uses the P-channel, back-illuminated type CCD with an imaging area size of 31mm on a side. The four CCD chips are arranged in a 2×2 grid and can be cooled down to -120 °C with a single-stage Stirling cooler. The XMA nests thin aluminum foils coated with gold in a confocal way with an outer diameter of 45 cm. A pre-collimator is installed in front of the x-ray mirror for the reduction of the stray light. Combining the SXI and XMA with a focal length of 5.6m, a field of view of 38′ × 38′ over the energy range from 0.4 to 13 keV is realized. We have completed the fabrication of the flight model of both SXI and XMA. The performance verification has been successfully conducted in a series of sub-system level tests. We also carried out on-ground calibration measurements and the data analysis is ongoing.
  • Aika Shimaguchi; Kumiko K Nobukawa; Shigeo Yamauchi; Masayoshi Nobukawa; Yutaka Fujita
    Publications of the Astronomical Society of Japan Oxford University Press (OUP) 74 (3) 656 - 663 0004-6264 2022/06 [Refereed]
     
    Abstract In this paper, we investigate the Fe K-shell lines in the supernova remnant W 51 C and hard X-ray sources in the proximity. We measure the intensities of the Fe i Kα and Fe xxv Heα lines at 6.40 and 6.68 keV, respectively, and find that the intensity of the 6.68 keV line is consistent with the background level expected from previous studies, while that of the 6.40 keV line is higher at the significance level of 2.0σ. Given the presence of gamma-ray emission and high ionization rate point spatially coincident with the remnant, we conclude that the enhanced 6.40 keV line most likely originates from the interaction between low-energy cosmic rays and molecular clouds. Also, we discover an enhanced 6.68 keV line emission from the compact H ii region G49.0−0.3 at a significance level of 3.4σ. Spectral analysis reveals that the temperature and abundance of the thermal plasma with the 6.68 keV line is $kT=3.0^{+0.8}_{-0.7}$ keV and Z = 0.5 ± 0.2 solar, respectively. These values are explained by the thermal plasma generated by the stellar winds of O stars.
  • H. Sano; H. Suzuki; K. K. Nobukawa; M. D. Filipović; Y. Fukui; T. J. Moriya
    The Astrophysical Journal American Astronomical Society 923 (1) 15 - 15 0004-637X 2021/12 [Refereed]
     
    Abstract We report on CO and H i studies of the mixed-morphology supernova remnant (SNR) G346.6−0.2. We find a wind-blown bubble along the radio continuum shell with an expansion velocity of ∼10 km s−1, which was likely formed by strong stellar winds from the high-mass progenitor of the SNR. The radial velocities of the CO/H i bubbles at VLSR = −82 to −59 km s−1 are also consistent with those of shock-excited 1720 MHz OH masers. The molecular cloud in the northeastern shell shows a high kinetic temperature of ∼60 K, suggesting that shock heating occurred. The H i absorption studies imply that G346.6−0.2 is located on the farside of the Galactic center from us, and the kinematic distance of the SNR is derived to be ${11.1}_{-0.3}^{+0.5}$ kpc. We find that the CO line intensity has no specific correlation with the electron temperature of recombining plasma, implying that the recombining plasma in G346.6−0.2 was likely produced by adiabatic cooling. With our estimates of the interstellar proton density of 280 cm−3 and gamma-ray luminosity <5.8 × 1034 erg s−1, the total energy of accelerated cosmic rays of Wp < 9.3 × 1047 erg is obtained. A comparison of the age–Wp relation to other SNRs suggests that most of the accelerated cosmic rays in G346.6−0.2 have escaped from the SNR shell.
  • Yutaka Fujita; Aya Bamba; Kumiko K. Nobukawa; Hironori Matsumoto
    The Astrophysical Journal American Astronomical Society 912 (2) 133 - 133 0004-637X 2021/05 [Refereed]
     
    We report the discovery of diffuse X-ray emission around the supernova remnant (SNR) G106.3+2.7, which is associated with VER J2227+608 and HAWC J2227+610 and is known as a candidate for a PeV cosmic-ray accelerator (PeVatron). We analyze observational data of Suzaku around the SNR and the adjacent pulsar PSR J2229+6114. We find diffuse X-ray emission that is represented by either thermal or nonthermal processes. However, the metal abundance for the thermal emission is <0.13 Z o˙, which may be too small in the Milky Way and suggests that the emission is nonthermal. The intensity of the diffuse emission increases toward PSR J2229+6114 in the same way as radio emission, and it is in contrast with gamma-ray emission concentrated on a molecular cloud. The X-ray photon index does not change with the distance from the pulsar and it indicates that radiative cooling is ineffective and particle diffusion is not extremely slow. The X-ray and radio emissions seem to be of leptonic origin and the parent electrons may originate from the pulsar. The gamma-ray emission appears to be of hadronic origin because of its spatial distribution. The parent protons may be tightly confined in the cloud separately from the diffusing electrons.
  • Yutaka Fujita; Kumiko K. Nobukawa; Hidetoshi Sano
    The Astrophysical Journal American Astronomical Society 908 (2) 136 - 136 2021/02 [Refereed]
  • Tomokage Yoneyama; Hirofumi Noda; Maho Hanaoka; Koki Okazaki; Kazunori Asakura; Kiyoshi Hayashida; Ayami Ishikura; Shotaro Sakuma; Kengo Hattori; Hironori Matsumoto; Koji Mori; Yoshiaki Kanemaru; Jin Sato; Toshiyuki Takaki; Hiroyuki Uchida; Takaaki Tanaka; Hiromichi Okon; Yuki Amano; Takeshi G. Tsuru; Hiroshi Tomida; Junko S. Hiraga; Yukino Urabe; Kumiko K. Nobukawa; Mariko Saito; Masayoshi Nobukawa; Takashi Sako; Hideki Uchiyama; Hiroshi Nakajima; Akira Kashimura; Shogo B. Kobayashi; Kouichi Hagino; Hiroshi Murakami
    Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Elsevier BV 985 164676 - 164676 0168-9002 2021/01 [Refereed]
  • Low-energy Cosmic Rays in Supernova Remnants Interacting with Molecular Clouds
    Kumiko K. Nobukawa
    Proceedings of the XIII Multifrequency Behaviour of High Energy Cosmic Sources Workshop 51  2020/12 [Refereed]
  • Yoshiaki Kanemaru; Jin Sato; Toshiyuki Takaki; Yuta Terada; Koji Mori; Mariko Saito; Kumiko K. Nobukawa; Takaaki Tanaka; Hiroyuki Uchida; Kiyoshi Hayashida; Hironori Matsumoto; Hirofumi Noda; Maho Hanaoka; Tomokage Yoneyama; Koki Okazaki; Kazunori Asakura; Shotaro Sakuma; Kengo Hattori; Ayami Ishikura; Yuki Amano; Hiromichi Okon; Takeshi G. Tsuru; Hiroshi Tomida; Hikari Kashimura; Hiroshi Nakajima; Takayoshi Kohmura; Kouichi Hagino; Hiroshi Murakami; Shogo B. Kobayashi; Yusuke Nishioka; Makoto Yamauchi; Isamu Hatsukade; Takashi Sako; Masayoshi Nobukawa; Yukino Urabe; Junko S. Hiraga; Hideki Uchiyama; Kazutaka Yamaoka; Masanobu Ozaki; Tadayasu Dotani; Hiroshi Tsunemi
    Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Elsevier BV 984 164646 - 164646 0168-9002 2020/12 [Refereed]
     
    We present experimental studies on the charge transfer inefficiency (CTI) of charge-coupled device (CCD) developed for the soft X-ray imaging telescope, Xtend, aboard the XRISM satellite. The CCD is equipped with a charge injection (CI) capability, in which sacrificial charge is periodically injected to fill the charge traps. By evaluating the re-emission of the trapped charge observed behind the CI rows, we find that there are at least three trap populations with different time constants. The traps with the shortest time constant, which is equivalent to a transfer time of approximately one pixel, are mainly responsible for the trailing charge of an X-ray event seen in the following pixel. A comparison of the trailing charge in two clocking modes reveals that the CTI depends not only on the transfer time but also on the area, namely the imaging or storage area. We construct a new CTI model by taking into account both transfer-time and area dependence. This model reproduces the data obtained in both clocking modes consistently. We also examine apparent flux dependence of the CTI observed without the CI technique. The higher incident X-ray flux is, the lower the CTI value becomes. It is due to a sacrificial charge effect by another X-ray photon. This effect is found to be negligible when the CI technique is used.
  • Shigeo Yamauchi; Moe Oya; Kumiko K Nobukawa; Thomas G Pannuti
    Publications of the Astronomical Society of Japan Oxford University Press ({OUP}) 72 (5) 0004-6264 2020/10 [Refereed]
     
    Abstract We present the results of an X-ray spectral analysis of the northeast region of the candidate supernova remnant G189.6+3.3 with Suzaku. K-shell lines from highly ionized Ne, Mg, Si, and S were detected in the spectrum for the first time. In addition, a radiative recombining continuum (RRC) from He-like Si was clearly seen near 2.5 keV. This detection of an RRC reveals for the first time that G189.6+3.3 possesses an X-ray-emitting recombining plasma (RP). The extracted X-ray spectrum in the 0.6–10.0 keV energy band is well fitted with a model consisting of a collisional ionization equilibrium plasma component (associated with the interstellar medium) and an RP component (associated with the ejecta). The spectral feature shows that G189.6+3.3 is most likely to be a middle-aged SNR with an RP.
  • Hiroyuki Uchida; Takaaki Tanaka; Yuki Amano; Hiromichi Okon; Takeshi G. Tsuru; Hiroshi Nakajima; Hirofumi Noda; Kiyoshi Hayashida; Hironori Matsumoto; Maho Hanaoka; Tomokage Yoneyama; Koki Okazaki; Kazunori Asakura; Shotaro Sakuma; Kengo Hattori; Ayami Ishikura; Mariko Saito; Kumiko K. Nobukawa; Hiroshi Tomida; Yoshiaki Kanemaru; Jin Sato; Toshiyuki Takaki; Yuta Terada; Koji Mori; Hikari Kashimura; Takayoshi Kohmura; Kouichi Hagino; Hiroshi Murakami; Shogo B. Kobayashi; Yusuke Nishioka; Makoto Yamauchi; Isamu Hatsukade; Takashi Sako; Masayoshi Nobukawa; Yukino Urabe; Junko S. Hiraga; Hideki Uchiyama; Kazutaka Yamaoka; Masanobu Ozaki; Tadayasu Dotani; Hiroshi Tsunemi; Hisanori Suzuki; Shin-ichiro Takagi; Kenichi Sugimoto; Sho Atsumi; Fumiya Tanaka
    Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Elsevier BV 978 164374 - 164374 0168-9002 2020/10 [Refereed]
  • Mariko Saito; Shigeo Yamauchi; Kumiko K Nobukawa; Aya Bamba; Thomas G Pannuti
    Publications of the Astronomical Society of Japan Oxford University Press ({OUP}) 72 (4) 0004-6264 2020/08 [Refereed]
     
    Abstract We present the results of a spectral analysis of the central region of the mixed-morphology supernova remnant HB 9. A prior Ginga observation of this source detected a hard X-ray component above 4 keV, and the origin of this particular X-ray component is still unknown. Our results demonstrate that the extracted X-ray spectra are best represented by a model consisting of a collisional ionization equilibrium plasma with a temperature of ∼0.1–0.2 keV (interstellar matter component) and an ionizing plasma with a temperature of ∼0.6–0.7 keV and an ionization timescale of &gt;1 × 1011 cm−3 s (ejecta component). No significant X-ray emission was found in the central region above 4 keV. The recombining plasma model reported by a previous work does not explain our spectra.
  • Kumiko K Nobukawa; Masayoshi Nobukawa; Shigeo Yamauchi
    Publications of the Astronomical Society of Japan Oxford University Press ({OUP}) 72 (2) 0004-6264 2020/04 [Refereed]
     
    Abstract We report the discovery of an annular emission of $\sim\!\! {3^{\prime } }\!-\!{9^{\prime } }$ radius around the center of a transient source, the X-ray burster MAXI J1421-613, in the Suzaku follow-up analysis. The spectrum of the annular emission shows no significant emission-line structure, and is well explained by an absorbed power-law model with a photon index of $\sim\!\! 4.2$. These features exclude the possibility that the annular emission is a shell-like component of a supernova remnant. The spectral shape, the time history, and the X-ray flux of the annular emission agree with the scenario that the emission is due to a dust-scattering echo. The annular emission is made under a rare condition of the dust-scattering echo, where the central X-ray source, MAXI J1421-613, exhibits a short time outburst with three X-ray bursts and immediately re-enters a long quiescent period. The distribution of the hydrogen column density along the annular emission follows that of the CO intensity, which means that MAXI J1421-613 is located behind the CO cloud. We estimate the distance to MAXI J1421-613 to be $\sim\!\! 3\:$kpc assuming that the dust layer responsible for the annular emission is located at the same position as the CO cloud.
  • Tomokage Yoneyama; Hirofumi Noda; Maho Hanaoka; Kiyoshi Hayashida; Koki Okazaki; Kazunori Asakura; Yoshiaki Kanemaru; Jin Sato; Toshiyuki Takaki; Koji Mori; Takashi Sako; Masayoshi Nobukawa; Mariko Saito; Kumiko K. Nobukawa; Hiroshi Murakami; Yuki Amano; Hiroyuki Uchida; Hideki Uchiyama; Hiroshi Tomida; Hiroshi Nakajima; Kengo Hattori; Shotaro Sakuma; Ayami Ishikura; Hironori Matsumoto; Hiromichi Okon; Takaaki Tanaka; Takeshi G. Tsuru; Yukino Urabe; Junko S. Hiraga; Akira Kashimura; Shogo B. Kobayashi; Kouichi Hagino
    Proceedings of SPIE - The International Society for Optical Engineering 11444 0277-786X 2020 
    X-Ray Imaging and Spectroscopy Mission (XRISM) is the seventh Japanese X-ray astronomical satellite scheduled to be launched in the Japanese fiscal year 2022. XRISM has two mission instruments, “Resolve”, a soft X-ray spectrometer, and “Xtend”, a soft X-ray imager. The Former is an X-ray micro-calorimeter that has ∼ 5 eV of energy resolution with 3′ × 3′ of field of view. The Latter is an X-ray CCD camera with 38′ × 38′ of field of view. Both instruments are placed on the focal plane of X-ray telescopes, X-ray Mirror Assembly (XMA). Xtend CCDs are designed almost the same as those of Hitomi (ASTRO-H), whereas some improvements have been applied. In 2019, flight-model (FM) candidates of Xtend CCDs were fabricated by Hamamatsu Photonics K.K. We performed screening experiments to examine whether they met requirements or not, and then selected the best four chips as the FM. We then performed on-ground calibration on August 2019 and September 2019 for the FM chips to determine the gain correction parameters and to construct the detector response with several energies of monochromatic X-ray. In this paper, we report screening, selection, and on-ground calibration processes, especially focusing on the response verification.
  • Kumiko K Nobukawa; Arisa Hirayama; Aika Shimaguchi; Yutaka Fujita; Masayoshi Nobukawa; Shigeo Yamauchi
    Publications of the Astronomical Society of Japan Oxford University Press ({OUP}) 71 (6) 0004-6264 2019/12 [Refereed]
     
    Abstract We report a discovery of bright blob-like enhancements of an Fe i K$\alpha$ line in the northwest and the middle of the supernova remnant (SNR) IC 443. The distribution of the line emission is associated with molecular clouds interacting with the shock front, and is totally different from that of the plasma. The Fe i K$\alpha$ line has a large equivalent width. The most plausible scenario for the origin of the line emission is that the MeV protons accelerated in the shell leak into the molecular clouds and ionized the Fe atoms therein. The observed Fe i K$\alpha$ line intensity is consistent with the prediction of a theoretical model in which MeV protons are accelerated along with GeV and TeV protons at the SNR.
  • Shoko Watanabe; Shigeo Yamauchi; Kumiko K Nobukawa; Hiroki Akamatsu
    Publications of the Astronomical Society of Japan Oxford University Press ({OUP}) 0004-6264 2019/10 [Refereed]
     
    Abstract The results of spectral analysis for the galaxy cluster IGR J17448$-$3232 are presented. The intracluster medium (ICM) in the central region ($r\lt 300^{\prime \prime }$, $320\:$kpc) has a high electron temperature plasma of $kT_{\rm e} \sim 13$–$15\:$keV, and an ionization temperature estimated from an intensity ratio of Fe xxvi Ly$\alpha /$Fe xxv He$\alpha$ lines is lower than the electron temperature, which suggests that the ICM is in the non-ionization equilibrium (NEI) state. The spectrum in the central region can be also fitted with a two-component model: a two-temperature plasma model in a collisional ionization equilibrium (CIE) with temperatures of $7.9\:$keV and $\gt 34\:$keV, or a CIE$+$power-law model with a temperature of $9.4\:$keV and a photon index of 1.1. The two-component models can represent the intensity ratio of Fe xxvi Ly$\alpha /$Fe xxv He$\alpha$ lines. On the other hand, the spectrum in the outer region ($r\gt 300^{\prime \prime }$) can be explained by a single CIE plasma model with a temperature of 5–$8\:$keV. Based on the spectral feature and its circular structure, we propose that the NEI plasma was produced by merging along the line-of-sight direction.
  • K. Makino; Y. Fujita; K. K. Nobukawa; H. Matsumoto; Y. Ohira
    Publications of the Astronomical Society of Japan 71 (4) 78  0004-6264 2019/08 [Refereed]
     
    Recent discovery of the X-ray neutral iron line (Fe i Kα at 6.40 keV) around several supernova remnants (SNRs) show that MeV cosmic-ray (CR) protons are distributed around the SNRs and are interacting with neutral gas there. We propose that these MeV CRs are the ones that have been accelerated at the SNRs together with GeV-TeV CRs. In our analytical model, the MeV CRs are still confined in the SNR when the SNR collides with molecular clouds. After the collision, the MeV CRs leak into the clouds and produce the neutral iron line emissions. On the other hand, GeV-TeV CRs had already escaped from the SNRs and emitted gamma-rays through interaction with molecular clouds surrounding the SNRs. We apply this model to the SNRs W 28 and W 44 and show that it can reproduce the observations of the iron line intensities and the gamma-ray spectra. This could be additional support of the hadronic scenario for the gamma-ray emissions from these SNRs.
  • Akiko Ono; Hideki Uchiyama; Shigeo Yamauchi; Masayoshi Nobukawa; Kumiko K. Nobukawa; Katsuji Koyama
    Publications of the Astronomical Society of Japan Oxford University Press (OUP) 71 (3) 52  0004-6264 2019/06 [Refereed]
  • Y. Kanemaru; J. Sato; K. Mori; H. Nakajima; Y. Nishioka; A. Takeda; K. Hayashida; H. Matsumoto; J. Iwagaki; K. Okazaki; K. Asakura; T. Yoneyama; H. Uchida; H. Okon; T. Tanaka; T. G. Tsuru; H. Tomida; T. Shimoi; T. Kohmura; K. Hagino; H. Murakami; S. B. Kobayashi; M. Yamauchia; I. Hatsukade; M. Nobukawa; K. K. Nobukawa; J. S. Hiraga; H. Uchiyama; K. Yamaoka; M. Ozaki; T. Dotani; H. Tsunemi; T. Hamano
    Journal of Instrumentation 14 (04) C04003  2019/04 [Refereed]
     
    We report the radiation hardness of a p-channel CCD developed for the X-ray CCD camera onboard the XRISM satellite. This CCD has basically the same characteristics as the one used in the previous Hitomi satellite, but newly employs a notch structure of potential for signal charges by increasing the implant concentration in the channel . The new device was exposed up to approximately 7.9 × 1010 protons cm-2 at 100 MeV . The charge transfer inefficiency was estimated as a function of proton fluence with an 55Fe source. A device without the notch structure was also examined for comparison. The result shows that the notch device has a significantly higher radiation hardness than those without the notch structure including the device adopted for Hitomi. This proves that the new CCD is radiation tolerant for space applications with a sufficient margin.
  • Kumiko K. Nobukawa; Shigetaka Saji; Arisa Hirayama; Masayoshi Nobukawa; Shigeo Yamauchi; Hironori Matsumoto; Katsuji Koyama
    Journal of Physics: Conference Series 1181 (1) 1742-6588 2019/03 
    There has been little information of Galactic low-energy cosmic rays (LECRs) so far because observations of LECRs in the solar system are affected by solar modulation and there is no effective way of indirect measurement. When LECRs in the MeV energy band collide with neutral iron atoms in the interstellar medium, uorescent X-rays at 6.4 keV are produced via inner-shell ionization of neutral iron atoms. We investigate the 6.4 keV line in supernova remnants (SNRs) as a prime candidate for the Galactic cosmic-ray origin. The line emission is discovered from 11 SNRs. The spectra and morphologies suggest that the 6.4 keV line is produced by LECRs interacting with cold gas. The proton energy density is estimated to be 10-100 eV cm-3. Furthermore, we measure the distribution of the 6.4 keV line emission near the Galactic center. The intensity profile is very similar to that of molecular clouds. The most plausible origin of the enhancement is the LECR proton bombardment. The energy density of MeV protons is estimated to be ∼ 80 eV cm-3. Since the diffusion length of MeV protons is short, they should be produced in situ. Surprisingly, there is no SNR in the vicinity, and thus another mechanism such as the stochastic acceleration would possibly work.
  • Arisa Hirayama; Shigeo Yamauchi; Kumiko K Nobukawa; Masayoshi Nobukawa; Katsuji Koyama
    Publications of the Astronomical Society of Japan Oxford University Press (OUP) 71 (2) 37  0004-6264 2019/01 [Refereed]
  • S. Yamauchi; M. Shimizu; M. Nobukawa; K. K. Nobukawa; H. Uchiyama; K. Koyama
    Publications of the Astronomical Society of Japan Oxford University Press (OUP) 70 (4) 82  0004-6264 2018/08 [Refereed]
  • Hitomi Collaboration; Felix Aharonian; Felix Aharonian; Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Steven W. Allen; Steven W. Allen; Lorella Angelini; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Aya Bamba; Aya Bamba, Marshall; W. Bautz; Roger Blandford; Roger Blandford; Roger Blandford; Laura W. Brenneman; Gregory V. Brown; Esra Bulbul; Edward M. Cackett; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Paolo S. Coppi; Elisa Costantini; Jelle De Plaa; Cor P. De Vries; Jan Willem Den Herder; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Margherita Giustini; Andrea Goldwurm; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Kenji Hamaguchi; Ilana M. Harrus; Ilana M. Harrus; Isamu Hatsukade; Katsuhiro Hayashi; Katsuhiro Hayashi; Takayuki Hayashi; Kiyoshi Hayashida; Junko S. Hiraga; Ann Hornschemeier; Akio Hoshino; John; P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Yoshiyuki Inoue; Manabu Ishida; Kumi Ishikawa; Yoshitaka Ishisaki; Masachika Iwai; Jelle Kaastra; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Jun Kataoka; Satoru Katsuda; Nobuyuki Kawai; Richard L. Kelley; Caroline A. Kilbourne; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans A. Krimm; Aya Kubota; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Shiu Hang Lee; Shiu Hang Lee; Maurice A. Leutenegger; Olivier Limousin
    Publications of the Astronomical Society of Japan Oxford University Press (OUP) 70 (3) 38  0004-6264 2018/06 [Refereed]
     
    We present results from the Hitomi X-ray observation of a young composite-type supernova remnant (SNR) G21.5-0.9, whose emission is dominated by the pulsar wind nebula (PWN) contribution. The X-ray spectra in the 0.8-80 keV range obtained with the Soft X-ray Spectrometer (SXS), Soft X-ray Imager, and Hard X-ray Imager (HXI) show a significant break in the continuum as previously found with the NuSTAR observation. After taking into account all known emissions from the SNR other than the PWN itself, we find that the Hitomi spectra can be fitted with a broken power law with photon indices of 1 = 1.74 ± 0.02 and 2 = 2.14 ± 0.01 below and above the break at 7.1 ± 0.3 keV, which is significantly lower than the NuSTAR result (∼9.0 keV). The spectral break cannot be reproduced by time-dependent particle injection one-zone spectral energy distribution models, which strongly indicates that a more complex emission model is needed, as suggested by recent theoretical models. We also search for narrow emission or absorption lines with the SXS, and perform a timing analysis of PSR J1833-1034 with the HXI and the Soft Gamma-ray Detector. No significant pulsation is found from the pulsar. However, unexpectedly, narrow absorption line features are detected in the SXS data at 4.2345 keV and 9.296 keV with a significance of 3.65 s. While the origin of these features is not understood, their mere detection opens up a new field of research and was only possible with the high resolution, sensitivity, and ability to measure extended sources provided by an X-ray microcalorimeter.
  • Hitomi Collaboration; Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Lorella Angelini; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Aya Bamba, Marshall; W. Bautz; Roger Blandford; Laura W. Brenneman; Gregory V. Brown; Esra Bulbul; Edward M. Cackett; Rebecca E. A. Canning; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Elisa Costantini; Jelle de Plaa; Cor P. de Vries; Jan-Willem den Herder; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Ilana M. Harrus; Isamu Hatsukade; Katsuhiro Hayashi; Takayuki Hayashi; Tasuku Hayashi; Kiyoshi Hayashida; Junko S. Hiraga; Ann Hornschemeier; Akio Hoshino; John; P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Shota Inoue; Yoshiyuki Inoue; Manabu Ishida; Kumi Ishikawa; Yoshitaka Ishisaki; Masachika Iwai; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Jun Kataoka; Satoru Katsuda; Nobuyuki Kawai; Richard L. Kelley; Caroline A. Kilbourne; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans A. Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Shiu-Hang Lee; Maurice A. Leutenegger; Olivier Limousin; Michael Loewenstein; Knox S. Long; David Lumb; Greg Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Brian R. McNamara; Missagh Mehdipour; Eric D. Miller; Jon M. Miller; Shin Mineshige; Kazuhisa Mitsuda; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Hideyuki Mori; Koji Mori; Koji Mukai; Hiroshi Murakami; Richard; F. Mushotzky; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Shinya Nakashima; Kazuhiro Nakazawa; Kumiko K. Nobukawa; Masayoshi Nobukawa; Hirofumi Noda; Hirokazu Odaka; Takaya Ohashi; Masanori Ohno; Takashi Okajima; Naomi Ota; Masanobu Ozaki; Frits Paerels; Stéphane Paltani; Robert Petre; Ciro Pinto; Frederick S. Porter; Katja Pottschmidt; Christopher S. Reynolds; Samar Safi-Harb; Shinya Saito; Kazuhiro Sakai; Toru Sasaki; Goro Sato; Kosuke Sato; Rie Sato; Makoto Sawada; Norbert Schartel; Peter J. Serlemtsos; Hiromi Seta; Megumi Shidatsu; Aurora Simionescu; Randall K. Smith; Yang Soong; Łukasz Stawarz; Yasuharu Sugawara; Satoshi Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Tadayuki Takahashi; Shin'ichiro Takeda; Yoh Takei; Toru Tamagawa; Takayuki Tamura; Keigo Tanaka; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki T. Tanaka; Makoto S. Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Go Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yasunobu Uchiyama; Shutaro Ueda; Yoshihiro Ueda; Shin'ichiro Uno; C. Megan Urry; Eugenio Ursino; Qian H. S. Wang; Shin Watanabe; Norbert Werner; Dan R. Wilkins; Brian J. Williams; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Y. Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Yoichi Yatsu; Daisuke Yonetoku; Irina Zhuravleva; Abderahmen Zoghbi
    Publications of the Astronomical Society of Japan Oxford University Press (OUP) 70 (2) 9  0004-6264 2018/04 [Refereed]
  • Hitomi Collaboration; Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Lorella Angelini; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Aya Bamba, Marshall; W. Bautz; Roger Blandford; Laura W. Brenneman; Greg V. Brown; Esra Bulbul; Edward M. Cackett; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Elisa Costantini; Jelle de Plaa; Cor P. de Vries; Jan-Willem den Herder; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Ilana M. Harrus; Isamu Hatsukade; Katsuhiro Hayashi; Takayuki Hayashi; Kiyoshi Hayashida; Junko S. Hiraga; Ann Hornschemeier; Akio Hoshino; John; P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Yoshiyuki Inoue; Manabu Ishida; Kumi Ishikawa; Yoshitaka Ishisaki; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Jun Kataoka; Satoru Katsuda; Nobuyuki Kawai; Richard L. Kelley; Caroline A. Kilbourne; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans A. Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Shiu-Hang Lee; Maurice A. Leutenegger; Olivier O. Limousin; Michael Loewenstein; Knox S. Long; David Lumb; Greg Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Brian R. McNamara; Missagh Mehdipour; Eric D. Miller; Jon M. Miller; Shin Mineshige; Kazuhisa Mitsuda; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Hideyuki Mori; Koji Mori; Koji Mukai; Hiroshi Murakami; Richard; F. Mushotzky; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Shinya Nakashima; Kazuhiro Nakazawa; Kumiko K. Nobukawa; Masayoshi Nobukawa; Hirofumi Noda; Hirokazu Odaka; Takaya Ohashi; Masanori Ohno; Takashi Okajima; Naomi Ota; Masanobu Ozaki; Frits Paerels; Stephane Paltani; Robert Petre; Ciro Pinto; Frederick S. Porter; Katja Pottschmidt; Christopher S. Reynolds; Samar Safi-Harb; Shinya Saito; Kazuhiro Sakai; Toru Sasaki; Goro Sato; Kosuke Sato; Rie Sato; Toshiki Sato; Makoto Sawada; Norbert Schartel; Peter J. Serlemtsos; Hiromi Seta; Megumi Shidatsu; Aurora Simionescu; Randall K. Smith; Yang Soong; Lukasz Stawarz; Yasuharu Sugawara; Satoshi Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Tadayuki Takahashi; Shinichiro Takeda; Yoh Takei; Toru Tamagawa; Takayuki Tamura; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki T. Tanaka; Makoto S. Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Go Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yasunobu Uchiyama; Shutaro Ueda; Yoshihiro Ueda; Shinichiro Uno; C. Megan Urry; Eugenio Ursino; Shin Watanabe; Norbert Werner; Dan R. Wilkins; Brian J. Williams; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Y. Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Yoichi Yatsu; Daisuke Yonetoku; Irina Zhuravleva; Abderahmen Zoghbi; Maki Furukawa; Anna Ogorzalek
    Publications of the Astronomical Society of Japan Oxford University Press (OUP) 70 (2) 10  0004-6264 2018/04 [Refereed]
  • Hitomi Collaboration; Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Lorella Angelini; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Aya Bamba, Marshall; W. Bautz; Roger Blandford; Laura W. Brenneman; Gregory V. Brown; Esra Bulbul; Edward M. Cackett; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Elisa Costantini; Jelle de Plaa; Cor P. de Vries; Jan-Willem den Herder; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Maki Furukawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Ilana M. Harrus; Isamu Hatsukade; Katsuhiro Hayashi; Takayuki Hayashi; Kiyoshi Hayashida; Junko S. Hiraga; Ann Hornschemeier; Akio Hoshino; John; P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Yoshiyuki Inoue; Manabu Ishida; Kumi Ishikawa; Yoshitaka Ishisaki; Masachika Iwai; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Jun Kataoka; Yuichi Kato; Satoru Katsuda; Nobuyuki Kawai; Richard L. Kelley; Caroline A. Kilbourne; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans A. Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Shiu-Hang Lee; Maurice A. Leutenegger; Olivier Limousin; Michael Loewenstein; Knox S. Long; David Lumb; Greg Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Brian R. McNamara; Missagh Mehdipour; Eric D. Miller; Jon M. Miller; Shin Mineshige; Kazuhisa Mitsuda; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Hideyuki Mori; Koji Mori; Koji Mukai; Hiroshi Murakami; Richard; F. Mushotzky; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Shinya Nakashima; Kazuhiro Nakazawa; Kumiko K. Nobukawa; Masayoshi Nobukawa; Hirofumi Noda; Hirokazu Odaka; Takaya Ohashi; Masanori Ohno; Takashi Okajima; Naomi Ota; Masanobu Ozaki; Frits Paerels; Stéphane Paltani; Robert Petre; Ciro Pinto; Frederick S. Porter; Katja Pottschmidt; Christopher S. Reynolds; Samar Safi-Harb; Shinya Saito; Kazuhiro Sakai; Toru Sasaki; Goro Sato; Kosuke Sato; Rie Sato; Makoto Sawada; Norbert Schartel; Peter J. Serlemtsos; Hiromi Seta; Megumi Shidatsu; Aurora Simionescu; Randall K. Smith; Yang Soong; Łukasz Stawarz; Yasuharu Sugawara; Satoshi Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Tadayuki Takahashi; Shiníchiro Takeda; Yoh Takei; Toru Tamagawa; Takayuki Tamura; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki T. Tanaka; Makoto S. Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Go Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yasunobu Uchiyama; Shutaro Ueda; Yoshihiro Ueda; Shiníchiro Uno; C. Megan Urry; Eugenio Ursino; Shin Watanabe; Norbert Werner; Dan R. Wilkins; Brian J. Williams; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Y. Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Yoichi Yatsu; Daisuke Yonetoku; Irina Zhuravleva; Abderahmen Zoghbi
    Publications of the Astronomical Society of Japan Oxford University Press (OUP) 70 (2) 11  0004-6264 2018/04 [Refereed]
  • Hitomi Collaboration; Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Lorella Angelini; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Aya Bamba, Marshall; W. Bautz; Roger Blandford; Laura W. Brenneman; Gregory V. Brown; Esra Bulbul; Edward M. Cackett; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Elisa Costantini; Jelle de Plaa; Cor P. de Vries; Jan-Willem den Herder; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Ilana M. Harrus; Isamu Hatsukade; Katsuhiro Hayashi; Takayuki Hayashi; Kiyoshi Hayashida; Natalie Hell; Junko S. Hiraga; Ann Hornschemeier; Akio Hoshino; John; P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Yoshiyuki Inoue; Manabu Ishida; Kumi Ishikawa; Yoshitaka Ishisaki; Masachika Iwai; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Jun Kataoka; Satoru Katsuda; Nobuyuki Kawai; Richard L. Kelley; Caroline A. Kilbourne; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans A. Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Shiu-Hang Lee; Maurice A. Leutenegger; Olivier Limousin; Michael Loewenstein; Knox S. Long; David Lumb; Greg Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Brian R. McNamara; Missagh Mehdipour; Eric D. Miller; Jon M. Miller; Shin Mineshige; Kazuhisa Mitsuda; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Hideyuki Mori; Koji Mori; Koji Mukai; Hiroshi Murakami; Richard; F. Mushotzky; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Shinya Nakashima; Kazuhiro Nakazawa; Kumiko K. Nobukawa; Masayoshi Nobukawa; Hirofumi Noda; Hirokazu Odaka; Takaya Ohashi; Masanori Ohno; Takashi Okajima; Naomi Ota; Masanobu Ozaki; Frits Paerels; Stéphane Paltani; Robert Petre; Ciro Pinto; Frederick S. Porter; Katja Pottschmidt; Christopher S. Reynolds; Samar Safi-Harb; Shinya Saito; Kazuhiro Sakai; Toru Sasaki; Goro Sato; Kosuke Sato; Rie Sato; Makoto Sawada; Norbert Schartel; Peter J. Serlemtsos; Hiromi Seta; Megumi Shidatsu; Aurora Simionescu; Randall K. Smith; Yang Soong; Łukasz Stawarz; Yasuharu Sugawara; Satoshi Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Tadayuki Takahashi; Shin'ichiro Takeda; Yoh Takei; Toru Tamagawa; Takayuki Tamura; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki T. Tanaka; Makoto S. Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Go Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yasunobu Uchiyama; Shutaro Ueda; Yoshihiro Ueda; Shin'ichiro Uno; C. Megan Urry; Eugenio Ursino; Shin Watanabe; Norbert Werner; Dan R. Wilkins; Brian J. Williams; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Y. Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Yoichi Yatsu; Daisuke Yonetoku; Irina Zhuravleva; Abderahmen Zoghbi; A. J. J. Raassen
    Publications of the Astronomical Society of Japan Oxford University Press (OUP) 70 (2) 12  0004-6264 2018/04 [Refereed]
  • Hitomi Collaboration; Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Lorella Angelini; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Aya Bamba, Marshall; W. Bautz; Roger Blandford; Laura W. Brenneman; Gregory V. Brown; Esra Bulbul; Edward M. Cackett; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Elisa Costantini; Jelle de Plaa; Cor P. de Vries; Jan-Willem den Herder; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Ilana M. Harrus; Isamu Hatsukade; Katsuhiro Hayashi; Takayuki Hayashi; Kiyoshi Hayashida; Junko S. Hiraga; Ann Hornschemeier; Akio Hoshino; John; P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Yoshiyuki Inoue; Manabu Ishida; Kumi Ishikawa; Yoshitaka Ishisaki; Masachika Iwai; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Jun Kataoka; Satoru Katsuda; Nobuyuki Kawai; Richard L. Kelley; Caroline A. Kilbourne; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans A. Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Shiu-Hang Lee; Maurice A. Leutenegger; Olivier O. Limousin; Michael Loewenstein; Knox S. Long; David Lumb; Greg Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Brian R. McNamara; Missagh Mehdipour; Eric D. Miller; Jon M. Miller; Shin Mineshige; Kazuhisa Mitsuda; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Hideyuki Mori; Koji Mori; Koji Mukai; Hiroshi Murakami; Richard; F. Mushotzky; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Shinya Nakashima; Kazuhiro Nakazawa; Kumiko K. Nobukawa; Masayoshi Nobukawa; Hirofumi Noda; Hirokazu Odaka; Takaya Ohashi; Masanori Ohno; Takashi Okajima; Naomi Ota; Masanobu Ozaki; Frits Paerels; Stéphane Paltani; Robert Petre; Ciro Pinto; Frederick S. Porter; Katja Pottschmidt; Christopher S. Reynolds; Samar Safi-Harb; Shinya Saito; Kazuhiro Sakai; Toru Sasaki; Goro Sato; Kosuke Sato; Rie Sato; Makoto Sawada; Norbert Schartel; Peter J. Serlemitsos; Hiromi Seta; Megumi Shidatsu; Aurora Simionescu; Randall K. Smith; Yang Soong; Łukasz Stawarz; Yasuharu Sugawara; Satoshi Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Tadayuki Takahashi; Shin'ichiro Takeda; Yoh Takei; Toru Tamagawa; Takayuki Tamura; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki T. Tanaka; Makoto S. Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Go Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yasunobu Uchiyama; Shutaro Ueda; Yoshihiro Ueda; Shin'ichiro Uno; C. Megan Urry; Eugenio Ursino; Shin Watanabe; Norbert Werner; Dan R. Wilkins; Brian J. Williams; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Y. Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Yoichi Yatsu; Daisuke Yonetoku; Irina Zhuravleva; Abderahmen Zoghbi; Taiki Kawamuro
    Publications of the Astronomical Society of Japan Oxford University Press (OUP) 70 (2) 13  0004-6264 2018/04 [Refereed]
  • Hitomi Collaboration; Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Lorella Angelini; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Aya Bamba, Marshall; W. Bautz; Roger Blandford; Laura W. Brenneman; Greg V. Brown; Esra Bulbul; Edward M. Cackett; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Elisa Costantini; Jelle de Plaa; Cor P. de Vries; Jan-Willem den Herder; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Ilana M. Harrus; Isamu Hatsukade; Katsuhiro Hayashi; Takayuki Hayashi; Kiyoshi Hayashida; Junko S. Hiraga; Ann Hornschemeier; Akio Hoshino; John; P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Yoshiyuki Inoue; Manabu Ishida; Kumi Ishikawa; Yoshitaka Ishisaki; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Jun Kataoka; Satoru Katsuda; Nobuyuki Kawai; Richard L. Kelley; Caroline A. Kilbourne; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans A. Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Shiu-Hang Lee; Maurice A. Leutenegger; Olivier O. Limousin; Michael Loewenstein; Knox S. Long; David Lumb; Greg Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Brian R. McNamara; Missagh Mehdipour; Eric D. Miller; Jon M. Miller; Shin Mineshige; Kazuhisa Mitsuda; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Hideyuki Mori; Koji Mori; Koji Mukai; Hiroshi Murakami; Richard; F. Mushotzky; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Shinya Nakashima; Kazuhiro Nakazawa; Kumiko K. Nobukawa; Masayoshi Nobukawa; Hirofumi Noda; Hirokazu Odaka; Takaya Ohashi; Masanori Ohno; Takashi Okajima; Naomi Ota; Masanobu Ozaki; Frits Paerels; Stephane Paltani; Robert Petre; Ciro Pinto; Frederick S. Porter; Katja Pottschmidt; Christopher S. Reynolds; Samar Safi-Harb; Shinya Saito; Kazuhiro Sakai; Toru Sasaki; Goro Sato; Kosuke Sato; Rie Sato; Toshiki Sato; Makoto Sawada; Norbert Schartel; Peter J. Serlemtsos; Hiromi Seta; Megumi Shidatsu; Aurora Simionescu; Randall K. Smith; Yang Soong; Lukasz Stawarz; Yasuharu Sugawara; Satoshi Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Tadayuki Takahashi; Shinichiro Takeda; Yoh Takei; Toru Tamagawa; Takayuki Tamura; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki T. Tanaka; Makoto S. Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Go Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yasunobu Uchiyama; Shutaro Ueda; Yoshihiro Ueda; Shinichiro Uno; C. Megan Urry; Eugenio Ursino; Shin Watanabe; Norbert Werner; Dan R. Wilkins; Brian J. Williams; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Y. Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Yoichi Yatsu; Daisuke Yonetoku; Irina Zhuravleva; Abderahmen Zoghbi; Nozomu Tominaga; Takashi J. Moriya
    Publications of the Astronomical Society of Japan Oxford University Press (OUP) 70 (2) 14  0004-6264 2018/04 [Refereed]
  • Hitomi Collaboration; Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Lorella Angelini; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Aya Bamba, Marshall; W. Bautz; Roger Blandford; Laura W. Brenneman; Gregory V. Brown; Esra Bulbul; Edward M. Cackett; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Elisa Costantini; Jelle de Plaa; Cor P. de Vries; Jan-Willem den Herder; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Ilana M. Harrus; Isamu Hatsukade; Katsuhiro Hayashi; Takayuki Hayashi; Kiyoshi Hayashida; Junko S. Hiraga; Ann Hornschemeier; Akio Hoshino; John; P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Yoshiyuki Inoue; Manabu Ishida; Kumi Ishikawa; Yoshitaka Ishisaki; Masachika Iwai; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Jun Kataoka; Satoru Katsuda; Nobuyuki Kawai; Richard L. Kelley; Caroline A. Kilbourne; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans A. Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Shiu-Hang Lee; Maurice A. Leutenegger; Olivier Limousin; Michael Loewenstein; Knox S. Long; David Lumb; Greg Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Brian R. McNamara; Missagh Mehdipour; Eric D. Miller; Jon M. Miller; Shin Mineshige; Kazuhisa Mitsuda; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Hideyuki Mori; Koji Mori; Koji Mukai; Hiroshi Murakami; Richard; F. Mushotzky; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Shinya Nakashima; Kazuhiro Nakazawa; Kumiko K. Nobukawa; Masayoshi Nobukawa; Hirofumi Noda; Hirokazu Odaka; Takaya Ohashi; Masanori Ohno; Takashi Okajima; Naomi Ota; Masanobu Ozaki; Frits Paerels; Stéphane Paltani; Robert Petre; Ciro Pinto; Frederick S. Porter; Katja Pottschmidt; Christopher S. Reynolds; Samar Safi-Harb; Shinya Saito; Kazuhiro Sakai; Toru Sasaki; Goro Sato; Kosuke Sato; Rie Sato; Toshiki Sato; Makoto Sawada; Norbert Schartel; Peter J. Serlemtsos; Hiromi Seta; Megumi Shidatsu; Aurora Simionescu; Randall K. Smith; Yang Soong; Łukasz Stawarz; Yasuharu Sugawara; Satoshi Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Tadayuki Takahashi; Shin'ichiro Takeda; Yoh Takei; Toru Tamagawa; Takayuki Tamura; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki T. Tanaka; Makoto S. Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Go Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yasunobu Uchiyama; Shutaro Ueda; Yoshihiro Ueda; Shin'ichiro Uno; C. Megan Urry; Eugenio Ursino; Shin Watanabe; Norbert Werner; Dan R. Wilkins; Brian J. Williams; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Y. Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Yoichi Yatsu; Daisuke Yonetoku; Irina Zhuravleva; Abderahmen Zoghbi
    Publications of the Astronomical Society of Japan Oxford University Press (OUP) 70 (2) 16  0004-6264 2018/04 [Refereed]
  • Hitomi Collaboration; Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Lorella Angelini; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Aya Bamba, Marshall; W. Bautz; Roger Blandford; Laura W. Brenneman; Gregory V. Brown; Esra Bulbul; Edward M. Cackett; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Elisa Costantini; Jelle de Plaa; Cor P. de Vries; Jan-Willem den Herder; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Ilana M. Harrus; Isamu Hatsukade; Katsuhiro Hayashi; Takayuki Hayashi; Kiyoshi Hayashida; Junko S. Hiraga; Ann Hornschemeier; Akio Hoshino; John; P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Yoshiyuki Inoue; Manabu Ishida; Kumi Ishikawa; Yoshitaka Ishisaki; Masachika Iwai; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Jun Kataoka; Satoru Katsuda; Nobuyuki Kawai; Richard L. Kelley; Caroline A. Kilbourne; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans A. Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Shiu-Hang Lee; Maurice A. Leutenegger; Olivier O. Limousin; Michael Loewenstein; Knox S. Long; David Lumb; Greg Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Brian R. McNamara; Missagh Mehdipour; Eric D. Miller; Jon M. Miller; Shin Mineshige; Kazuhisa Mitsuda; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Hideyuki Mori; Koji Mori; Koji Mukai; Hiroshi Murakami; Richard; F. Mushotzky; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Shinya Nakashima; Kazuhiro Nakazawa; Kumiko K. Nobukawa; Masayoshi Nobukawa; Hirofumi Noda; Hirokazu Odaka; Takaya Ohashi; Masanori Ohno; Takashi Okajima; Naomi Ota; Masanobu Ozaki; Frits Paerels; Stéphane Paltani; Robert Petre; Ciro Pinto; Frederick S. Porter; Katja Pottschmidt; Christopher S. Reynolds; Samar Safi-Harb; Shinya Saito; Kazuhiro Sakai; Toru Sasaki; Goro Sato; Kosuke Sato; Rie Sato; Makoto Sawada; Norbert Schartel; Peter J. Serlemitsos; Hiromi Seta; Megumi Shidatsu; Aurora Simionescu; Randall K. Smith; Yang Soong; Łukasz Stawarz; Yasuharu Sugawara; Satoshi Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Tadayuki Takahashi; Shin'ichiro Takeda; Yoh Takei; Toru Tamagawa; Takayuki Tamura; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki T. Tanaka; Makoto S. Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Go Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yasunobu Uchiyama; Shutaro Ueda; Yoshihiro Ueda; Shin'ichiro Uno; C. Megan Urry; Eugenio Ursino; Shin Watanabe; Norbert Werner; Dan R. Wilkins; Brian J. Williams; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Y. Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Yoichi Yatsu; Daisuke Yonetoku; Irina Zhuravleva; Abderahmen Zoghbi; Nozomi Nakaniwa
    Publications of the Astronomical Society of Japan Oxford University Press (OUP) 70 (2) 17  0004-6264 2018/04 [Refereed]
  • H. Nakajima; Y. Maeda; H. Uchida; T. Tanaka; H. Tsunemi; K. Hayashida; T. G. Tsuru; T. Dotani; R. Nagino; S. Inoue; M. Ozaki; H. Tomida; C. Natsukari; S. Ueda; K. Mori; M. Yamauchi; I. Hatsukade; Y. Nishioka; M. Sakata; T. Beppu; D. Honda; M. Nobukawa; J. S. Hiraga; T. Kohmura; H. Murakami; K. K. Nobukawa; A. Bamba; J. P. Doty; R. Iizuka; T. Sato; S. Kurashima; N. Nakaniwa; R. Asai; M. Ishida; H. Mori; Y. Soong; T. Okajima; P. Serlemitsos; Y. Tawara; I. Mitsuishi; K. Ishibashi; K. Tamura; T. Hayashi; A. Furuzawa; S. Sugita; T. Miyazawa; H. Awaki; E. D. Miller; H. Yamaguchi
    Publications of the Astronomical Society of Japan OXFORD UNIV PRESS 70 (2) 21  0004-6264 2018/04 [Refereed]
     
    We describe the in-orbit performance of the soft X-ray imaging system consisting of the Soft X-ray Telescope and the Soft X-ray Imager aboard Hitomi. Verification and calibration of imaging and spectroscopic performance are carried out, making the best use of the limited data of less than three weeks. Basic performance, including a large field of view of 38' x 38', is verified with the first-light image of the Perseus cluster of galaxies. Amongst the small number of observed targets, the on-minus-off pulse image for the out-of-time events of the Crab pulsar enables us to measure the half-power diameter of the telescope as similar to 1.'3. The average energy resolution measured with the onboard calibration source events at 5.89 keV is 179 +/- 3 eV in full width at half maximum. Light leak and crosstalk issues affected the effective exposure time and the effective area, respectively, because all the observations were performed before optimizing an observation schedule and the parameters for the dark-level calculation. Screening the data affected by these two issues, we measure the background level to be 5.6 x 10(-6) counts s(-1) arcmin(-2) cm(-2) in the energy band of 5-12 keV, which is seven times lower than that of the Suzaku XIS-BI.
  • Tadayuki Takahashi; Motohide Kokubun; Kazuhisa Mitsuda; Richard L. Kelley; Takaya Ohashi; Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Naohisa Anabuki; Lorella Angelini; Keith Arnaud; Makoto Asai; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Philipp Azzarello; Chris Baluta; Aya Bamba; Nobutaka Bando; Marshall W. Bautz; Thomas Bialas; Roger Blandford; Kevin Boyce; Laura W. Brenneman; Gregory V. Brown; Esra Bulbul; Edward M. Cackett; Edgar Canavan; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Elisa Costantini; Steve O' Dell; Michael DiPirro; Chris Done; Tadayasu Dotani; John Doty; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Stefan Funk; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Kirk Gilmore; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Daniel Haas; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Ilana M. Harrus; Isamu Hatsukade; Takayuki Hayashi; Katsuhiro Hayashi; Kiyoshi Hayashida; Jan Willem Den Herder; Junko S. Hiraga; Kazuyuki Hirose; Ann Hornschemeier; Akio Hoshino; John P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Yoshiyuki Inoue; Kazunori Ishibashi; Manabu Ishida; Kumi Ishikawa; Kosei Ishimura; Yoshitaka Ishisaki; Masayuki Itoh; Masachika Iwai; Naoko Iwata; Naoko Iyomoto; Chris Jewell; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Erin Kara; Jun Kataoka; Satoru Katsuda; Junichiro Katsuta; Madoka Kawaharada; Nobuyuki Kawai; Taro Kawano; Shigeo Kawasaki; Dmitry Khangulyan; Caroline A. Kilbourne; Mark Kimball
    Journal of Astronomical Telescopes, Instruments, and Systems 4 (2) 021402  2329-4124 2018/04 [Refereed]
     
    © The Authors. The Hitomi (ASTRO-H) mission is the sixth Japanese x-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E > 2 keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decades in energy from soft x-rays to gamma rays. After a successful launch on February 17, 2016, the spacecraft lost its function on March 26, 2016, but the commissioning phase for about a month provided valuable information on the onboard instruments and the spacecraft system, including astrophysical results obtained from first light observations. The paper describes the Hitomi (ASTRO-H) mission, its capabilities, the initial operation, and the instruments/spacecraft performances confirmed during the commissioning operations for about a month.
  • Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Lorella Angelini; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Aya Bamba; Marshall W. Bautz; Roger Blandford; Laura W. Brenneman; Gregory V. Brown; Esra Bulbul; Edward M. Cackett; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Elisa Costantini; Jelle De Plaa; Cor P. De Vries; Jan Willem Den Herder; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Ilana M. Harrus; Isamu Hatsukade; Katsuhiro Hayashi; Takayuki Hayashi; Kiyoshi Hayashida; Junko S. Hiraga; Ann Hornschemeier; Akio Hoshino; John P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Yoshiyuki Inoue; Manabu Ishida; Kumi Ishikawa; Yoshitaka Ishisaki; Masachika Iwai; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Jun Kataoka; Satoru Katsuda; Nobuyuki Kawai; Richard L. Kelley; Caroline A. Kilbourne; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans A. Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; L. E.E. Shiu-Hang; Maurice A. Leutenegger; Olivier O. Limousin; Michael Loewenstein; Knox S. Long; David Lumb; Greg Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Brian R. McNamara; Missagh Mehdipour; Eric D. Miller; Jon M. Miller; Shin Mineshige
    Publications of the Astronomical Society of Japan 70 (2) 15  0004-6264 2018/03 [Refereed]
     
    © The Author(s) 2017. Published by Oxford University Press on behalf of the Astronomical Society of Japan. To search for giant X-ray pulses correlated with the giant radio pulses (GRPs) from the Crab pulsar, we performed a simultaneous observation of the Crab pulsar with the X-ray satellite Hitomi in the 2-300 keV band and the Kashima NICT radio telescope in the 1.4-1.7 GHz band with a net exposure of about 2 ks on 2016 March 25, just before the loss of the Hitomi mission. The timing performance of the Hitomi instruments was confirmed to meet the timing requirement and about 1000 and 100 GRPs were simultaneously observed at the main pulse and inter-pulse phases, respectively, and we found no apparent correlation between the giant radio pulses and the X-ray emission in either the main pulse or inter-pulse phase. All variations are within the 2 σ fluctuations of the X-ray fluxes at the pulse peaks, and the 3 σ upper limits of variations of main pulse or inter-pulse GRPs are 22% or 80% of the peak flux in a 0.20 phase width, respectively, in the 2-300 keV band. The values for main pulse or inter-pulse GRPs become 25% or 110%, respectively, when the phase width is restricted to the 0.03 phase. Among the upper limits from the Hitomi satellite, those in the 4.5-10 keV and 70-300 keV bands are obtained for the first time, and those in other bands are consistent with previous reports. Numerically, the upper limits of the main pulse and inter-pulse GRPs in the 0.20 phase width are about (2.4 and 9.3) × 10−11 erg cm−2, respectively. No significant variability in pulse profiles implies that the GRPs originated from a local place within the magnetosphere. Although the number of photon-emitting particles should temporarily increase to account for the brightening of the radio emission, the results do not statistically rule out variations correlated with the GRPs, because the possible X-ray enhancement may appear due to a >0.02% brightening of the pulse-peak flux under such conditions.
  • Kumiko K. Nobukawa; Masayoshi Nobukawa; Katsuji Koyama; Shigeo Yamauchi; Hideki Uchiyama; Hiromichi Okon; Takaaki Tanaka; Hiroyuki Uchida; Takeshi G. Tsuru
    Astrophysical Journal Institute of Physics Publishing 854 (2) 87  1538-4357 2018/02 [Refereed]
     
    Supernova remnants (SNRs) have been prime candidates for Galactic cosmic-ray accelerators. When low-energy cosmic-ray protons (LECRp) collide with interstellar gas, they ionize neutral iron atoms and emit the neutral iron line (Fe i Kα) at 6.40 keV. We search for the iron K-shell line in seven SNRs from the Suzaku archive data of the Galactic plane in the 6° ≲ l ≲ 40°, < 1° region. All of these SNRs interact with molecular clouds. We discover Fe i Kα line emissions from five SNRs (W28, Kes 67, Kes 69, Kes 78, and W44). The spectra and morphologies suggest that the Fe i Kα line is produced by interactions between LECRp and the adjacent cold gas. The proton energy density is estimated to be 10-100 eV cm-3, which is more than 10 times higher than that in the ambient interstellar medium.
  • Aya Bamba; Yutaka Ohira; Ryo Yamazaki; Makoto Sawada; Yukikatsu Terada; Katsuji Koyama; Eric D. Miller; Hiroya Yamaguchi; Satoru Katsuda; Masayoshi Nobukawa; Kumiko K. Nobukawa
    Astrophysical Journal Institute of Physics Publishing 854 (1) 71  1538-4357 2018/02 [Refereed]
     
    Supernova remnants (SNRs) are the primary candidate of Galactic cosmic-ray accelerators. It is still an open issue when and how young SNRs, which typically exhibit strong synchrotron X-rays and GeV and TeV gamma rays, undergo the state transition to middle-aged SNRs dominated by thermal X-rays and GeV gamma rays. SNR N132D in the Large Magellanic Cloud is an ideal target to study such a transition, exhibiting bright X-rays and gamma rays, and with an expected age of ∼2500 years. In this paper we present results of NuSTAR and Suzaku spectroscopy. We reveal that N132D has a nearly equilibrium plasma with a temperature of > 5 keV or a recombining plasma with a lower temperature (∼1.5 keV) and a recombining timescale (net) of cm-3s. Together with the center-filled morphology observed in the iron K line image, our results suggest that N132D is now at the transition stage from being a young SNR to being middle-aged. We have constrained the tight upper limit of nonthermal X-rays. Bright gamma rays compared to faint nonthermal X-rays suggest that the gamma rays are hadronic in origin. The spectral energy distribution from radio to gamma rays shows a proton cutoff energy of ∼30 TeV. These facts confirm that N132D is undergoing the transition from a young to a middle-aged SNR. The large thermal energy of erg and accelerated proton energy of erg suggest the supernova explosion might have been very energetic.
  • Shigetaka Saji; Hironori Matsumoto; Masayoshi Nobukawa; Kumiko K. Nobukawa; Hideki Uchiyama; Shigeo Yamauchi; Katsuji Koyama
    Publications of the Astronomical Society of Japan Oxford University Press (OUP) 70 (2) 23  0004-6264 2018/02 [Refereed]
  • Makoto Tashiro; Hironori Maejima; Kenichi Toda; Richard Kelley; Lillian Reichenthal; James Lobell; Robert Petre; Matteo Guainazzi; Elisa Costantini; Mark Edison; Ryuichi Fujimoto; Martin Grim; Kiyoshi Hayashida; Jan-Willem den Herder; Yoshitaka Ishisaki; Stephane Paltani; Kyoko Matsushita; Koji Mori; Gary Sneiderman; Yoh Takei; Yukikatsu Terada; Hiroshi Tomida; Hiroki Akamatsu; Lorella Angelini; Yoshitaka Arai; Hisamitsu Awaki; Iurii Babyk; Aya Bamba; Peter Barfknecht; Kim Barnstable; Thomas Bialas; Branimir Blagojevic; Joseph Bonafede; Clifford Brambora; Laura Brenneman; Greg Brown; Kimberly Brown; Laura Burns; Edgar Canavan; Tim Carnahan; Meng Chiao; Brian Comber; Lia Corrales; Cor de Vries; Johannes Dercksen; Maria Diaz-Trigo; Tyrone Dillard; Michael DiPirro; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan Eckart; Teruaki Enoto; Yuichiro Ezoe; Carlo Ferrigno; Yutaka Fujita; Yasushi Fukazawa; Akihiro Furuzawa; Luigi Gallo; Steve Graham; Liyi Gu; Kohichi Hagino; Kenji Hamaguchi; Isamu Hatsukade; Dean Hawes; Takayuki Hayashi; Cailey Hegarty; Natalie Hell; Junko Hiraga; Edmund Hodges-Kluck; Matt Holland; Ann Hornschemeier; Akio Hoshino; Yuto Ichinohe; Ryo Iizuka; Kazunori Ishibashi; Manabu Ishida; Kumi Ishikawa; Kosei Ishimura; Bryan James; Timothy Kallman; Erin Kara; Satoru Katsuda; Steven Kenyon; Caroline Kilbourne; Mark Kimball; Takao Kitaguchi; Shunji Kitamoto; Shogo Kobayashi; Takayoshi Kohmura; Shu Koyama; Aya Kubota; Maurice Leutenegger; Tom Lockard; Mike Loewenstein; Yoshitomo Maeda; Lynette Marbley; Maxim Markevitch; Connor Martz; Hironori Matsumoto; Keiichi Matsuzaki; Dan McCammon; Brian McNamara; Joseph Miko; Eric Miller; Jon Miller; Kenji Minesugi; Ikuyuki Mitsuishi; Tsunefumi Mizuno; Hideyuki Mori; Koji Mukai; Hiroshi Murakami; Richard Mushotzky; Hiroshi Nakajima; Hideto Nakamura; Shinya Nakashima; Kazuhiro Nakazawa; Chikara Natsukari; Kenichiro Nigo; Yusuke Nishioka; Kumiko Nobukawa; Masayoshi Nobukawa; Hirofumi Noda; Hirokazu Odaka; Mina Ogawa; Takaya Ohashi; Masahiro Ohno; Masayuki Ohta; Takashi Okajima; Atsushi Okamoto; Michitaka Onizuka; Naomi Ota; Masanobu Ozaki; Paul Plucinsky; F. Scott Porter; Katja Pottschmidt; Kosuke Sato; Rie Sato; Makoto Sawada; Hiromi Seta; Ken Shelton; Yasuko Shibano; Maki Shida; Megumi Shidatsu; Peter Shirron; Aurora Simionescu; Randall Smith; Kazunori Someya; Yang Soong; Yasuharu Sugawara; Andy Szymkowiak; Hiromitsu Takahashi; Toru Tamagawa; Takayuki Tamura; Takaaki Tanaka; Yuichi Terashima; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yoshihiro Ueda; Shinichiro Uno; Thomas Walsh; Shin Watanabe; Brian Williams; Rob Wolfs; Michael Wright; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Yamasaki; Shigeo Yamauchi; Makoto Yamauchi; Keiichi Yanagase; Tahir Yaqoob; Susumu Yasuda; Nasa Yoshioka; Jaime Zabala; Irina Zhuravleva
    SPACE TELESCOPES AND INSTRUMENTATION 2018: ULTRAVIOLET TO GAMMA RAY SPIE-INT SOC OPTICAL ENGINEERING 10699 22  0277-786X 2018 
    The ASTRO-H mission was designed and developed through an international collaboration of JAXA, NASA, ESA, and the CSA. It was successfully launched on February 17, 2016, and then named Hitomi. During the in-orbit verification phase, the on-board observational instruments functioned as expected. The intricate coolant and refrigeration systems for soft X-ray spectrometer (SXS, a quantum micro-calorimeter) and soft X-ray imager (SXI, an X-ray CCD) also functioned as expected. However, on March 26, 2016, operations were prematurely terminated by a series of abnormal events and mishaps triggered by the attitude control system. These errors led to a fatal event: the loss of the solar panels on the Hitomi mission. The X-ray Astronomy Recovery Mission (or, XARM) is proposed to regain the key scientific advances anticipated by the international collaboration behind Hitomi. XARM will recover this science in the shortest time possible by focusing on one of the main science goals of Hitomi, "Resolving astrophysical problems by precise high-resolution X-ray spectroscopy".(1) This decision was reached after evaluating the performance of the instruments aboard Hitomi and the mission's initial scientific results, and considering the landscape of planned international X-ray astrophysics missions in 2020's and 2030's.Hitomi opened the door to high-resolution spectroscopy in the X-ray universe. It revealed a number of discrepancies between new observational results and prior theoretical predictions. Yet, the resolution pioneered by Hitomi is also the key to answering these and other fundamental questions. The high spectral resolution realized by XARM will not offer mere refinements; rather, it will enable qualitative leaps in astrophysics and plasma physics. XARM has therefore been given a broad scientific charge: "Revealing material circulation and energy transfer in cosmic plasmas and elucidating evolution of cosmic structures and objects". To fulfill this charge, four categories of science objectives that were defined for Hitomi will also be pursued by XARM; these include (1) Structure formation of the Universe and evolution of clusters of galaxies; (2) Circulation history of baryonic matters in the Universe; (3) Transport and circulation of energy in the Universe; (4) New science with unprecedented high resolution X-ray spectroscopy. In order to achieve these scientific objectives, XARM will carry a 6 x 6 pixelized X-ray micro-calorimeter on the focal plane of an X-ray mirror assembly, and an aligned X-ray CCD camera covering the same energy band and a wider field of view. This paper introduces the science objectives, mission concept, and observing plan of XARM.
  • Kiyoshi Hayashida; Hiroshi Tomida; Koji Mori; Hiroshi Nakajima; Takaaki Tanaka; Hiroyuki Uchida; Takeshi G. Tsuru; Hiroshi Murakami; Takashi Okajima; Takayoshi Kohmura; Kouichi Hagino; Shogo B. Kobayashi; Manabu Ishida; Yoshitomo Maeda; Hideki Uchiyama; Kazutaka Yamaoka; Hironori Matsumoto; Masayoshi Nobukawa; Kumiko K; Nobukawa; Junko S. Hiraga; Makoto Yamauchi; Isamu Hatsukade; Yang Soong; Hideyuki Mori; Takayuki Hayashi; Hiroshi Tsunemi; Masanobu Ozaki; Tadayasu Dotani; Junichi Iwagaki; Tomokage Yoneyama; Koki Okazaki; Kazunori Asakura; Satomi Onishi; Yoshiaki Kanemaru; Jin Sato; Yusuke Nishioka; Ayaki Takeda; Hiromichi Okon; Masayuki Yoshida; Takeo Shimoi
    Proceedings of SPIE - The International Society for Optical Engineering SPIE-INT SOC OPTICAL ENGINEERING 10699 23  0277-786X 2018/01 
    X-ray Astronomy Recovery Mission (XARM) scheduled to be launched in early 2020's carries two soft X-ray telescopes. One is Resolve consisting of a soft X-ray mirror and a micro calorimeter array, and the other is Soft X-ray Imaging Telescope (Xtend), a combination of an X-ray mirror assembly (XMA) and an X-ray CCD camera (SXI). Xtend covers a field of view (FOV) of 38′ × 38′, much larger than that of Resolve (3′ × 3 ′) with moderate energy resolution in the energy band from 0.4 keV to 13 keV, which is similar to that of Resolve (from 0.3 keV to 12 keV). Simultaneous observations of both telescopes provide complimentary data of X-ray sources in their FOV. In particular, monitoring X-ray sources outside the Resolve FOV but inside the Xtend FOV is important to enhance the reliability of super high resolution spectra obtained with Resolve. Xtend is also expected to be one of the best instruments for low surface brightness X-ray emissions with its low non X-ray background level, which is comparable to that of Suzaku XIS. The design of Xtend is almost identical to those of Soft X-ray Telescope (SXT) and Soft X-ray Imager (SXI) both on board the Hitomi satellite. However, several mandatory updates are included. Updates for the CCD chips are verified with experiment using test CCD chips before finalizing the design of the flight model CCD. Fabrication of the foils for XMA has started, and flight model production of the SXI is almost ready.
  • Takaaki Tanaka; Hiroyuki Uchida; Hiroshi Nakajima; Hiroshi Tsunemi; Kiyoshi Hayashida; Takeshi Go Tsuru; Tadayasu Dotani; Ryo Nagino; Shota Inoue; Shuhei Katada; Ryosaku Washino; Masanobu Ozaki; Hiroshi Tomida; Chikara Natsukari; Shutaro Ueda; Masachika Iwai; Koji Mori; Makoto Yamauchi; Isamu Hatsukade; Yusuke Nishioka; Eri Isoda; Masayoshi Nobukawa; Junko S. Hiraga; Takayoshi Kohmura; Hiroshi Murakami; Kumiko K. Nobukawa; Aya Bamba; John P. Doty
    Journal of Astronomical Telescopes, Instruments, and Systems SPIE 4 (1) 011211  2329-4221 2018/01 [Refereed]
     
    The Soft X-ray Imager (SXI) is an imaging spectrometer using charge-coupled devices (CCDs) aboard the Hitomi x-ray observatory. The SXI sensor has four CCDs with an imaging area size of 31 mm × 31 mm arranged in a 2 × 2 array. Combined with the x-ray mirror, the Soft X-ray Telescope, the SXI detects x-rays between 0.4 and 12 keV and covers a 38′ × 38′ field of view. The CCDs are P-channel fully depleted, back-illumination type with a depletion layer thickness of 200 μm. Low operation temperature down to -120°C as well as charge injection is employed to reduce the charge transfer inefficiency (CTI) of the CCDs. The functionality and performance of the SXI are verified in on-ground tests. The energy resolution measured is 161 to 170 eV in full width at half maximum for 5.9-keV x-rays. In the tests, we found that the CTI of some regions is significantly higher. A method is developed to properly treat the position-dependent CTI. Another problem we found is pinholes in the Al coating on the incident surface of the CCDs for optical light blocking. The Al thickness of the contamination blocking filter is increased to sufficiently block optical light.
  • Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Lorella Angelini; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Aya Bamba; Marshall W. Bautz; Roger Blandford; Laura W. Brenneman; Gregory V. Brown; Esra Bulbul; Edward M. Cackett; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Elisa Costantini; Jelle De Plaa; Jan-Willem den Herder; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Ilana M. Harrus; Isamu Hatsukade; Katsuhiro Hayashi; Takayuki Hayashi; Kiyoshi Hayashida; Junko S. Hiraga; Ann Hornschemeier; Akio Hoshino; John P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Yoshiyuki Inoue; Manabu Ishida; Kumi Ishikawa; Yoshitaka Ishisaki; Masachika Iwai; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Jun Kataoka; Satoru Katsuda; Nobuyuki Kawai; Richard L. Kelley; Caroline A. Kilbourne; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans A. Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Shiu-Hang Lee; Maurice A. Leutenegger; Olivier Limousine; Michael Loewenstein; Knox S. Long; David Lumb; Greg Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Brian R. McNamara; Missagh Mehdipour; Eric D. Miller; Jon M. Miller; Shin Mineshige; Kazuhisa Mitsuda; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Hideyuki Mori; Koji Mori; Koji Mukai; Hiroshi Murakami; Richard F. Mushotzky; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Shinya Nakashima; Kazuhiro Nakazawa; Kumiko K. Nobukawa; Masayoshi Nobukawa; Hirofumi Noda; Hirokazu Odaka; Takaya Ohashi; Masanori Ohno; Takashi Okajima; Naomi Ota; Masanobu Ozaki; Frits Paerels; StPhane Paltani; Robert Petre; Ciro Pinto; Frederick S. Porter; Katja Pottschmidt; Christopher S. Reynolds; Samar Safi-Harb; Shinya Saito; Kazuhiro Sakai; Toru Sasaki; Goro Sato; Kosuke Sato; Rie Sato; Makoto Sawada; Norbert Schartel; Peter J. Serlemitsos; Hiromi Seta; Megumi Shidatsu; Aurora Simionescu; Randall K. Smith; Yang Soong; Lukasz Stawarz; Yasuharu Sugawara; Satoshi Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Tadayuki Takahashi; Shin'ichiro Takeda; Yoh Takei; Toru Tamagawa; Takayuki Tamura; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki T. Tanaka; Makoto S. Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Go Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yasunobu Uchiyama; Shutaro Ueda; Yoshihiro Ueda; Shin'ichiro Uno; C. Megan Urry; Eugenio Ursino; Cor P. de Vries; Shin Watanabe; Norbert Werner; Daniel R. Wik; Dan R. Wilkins; Brian J. Williams; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Y. Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Yoichi Yatsu; Daisuke Yonetoku; Irina Zhuravleva; Abderahmen Zoghbi
    NATURE NATURE PUBLISHING GROUP 551 (7681) 478 - + 0028-0836 2017/11 [Refereed]
     
    The metal abundance of the hot plasma that permeates galaxy clusters represents the accumulation of heavy elements produced by billions of supernovae(1). Therefore, X-ray spectroscopy of the intracluster medium provides an opportunity to investigate the nature of supernova explosions integrated over cosmic time. In particular, the abundance of the iron-peak elements (chromium, manganese, iron and nickel) is key to understanding how the progenitors of typical type Ia supernovae evolve and explode(2-6). Recent X-ray studies of the intracluster medium found that the abundance ratios of these elements differ substantially from those seen in the Sun(7-11), suggesting differences between the nature of type Ia supernovae in the clusters and in the Milky Way. However, because the K-shell transition lines of chromium and manganese are weak and those of iron and nickel are very close in photon energy, highresolution spectroscopy is required for an accurate determination of the abundances of these elements. Here we report observations of the Perseus cluster, with statistically significant detections of the resonance emission from chromium, manganese and nickel. Our measurements, combined with the latest atomic models, reveal that these elements have near-solar abundance ratios with respect to iron, in contrast to previous claims. Comparison between our results and modern nucleosynthesis calculations(12-14) disfavours the hypothesis that type Ia supernova progenitors are exclusively white dwarfs with masses well below the Chandrasekhar limit (about 1.4 times the mass of the Sun). The observed abundance pattern of the iron-peak elements can be explained by taking into account a combination of near-and sub-Chandrasekhar-mass type Ia supernova systems, adding to the mounting evidence that both progenitor types make a substantial contribution to cosmic chemical enrichment(5,15,16).
  • M. Nobukawa; K. K. Nobukawa; S. Yamauchi; H. Uchiyama; K. Koyama
    Proceedings of the XII Multifrequency Behaviour of High Energy Cosmic Sources Workshop 55  2017/06 [Refereed]
  • Hideaki Matsumura; Hiroyuki Uchida; Takaaki Tanaka; Takeshi Go Tsuru; Masayoshi Nobukawa; Kumiko Kawabata Nobukawa; Makoto Itou
    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN OXFORD UNIV PRESS 69 (2) 30  0004-6264 2017/04 [Refereed]
     
    We observed the Galactic mixed-morphology supernova remnant G166.0+4.3 with Suzaku. The X-ray spectrum in the western part of the remnant is well represented by a one-component ionizing plasma model. The spectrum in the northeastern region can be explained by two components. One is an Fe-rich component with electron temperature kTe = 0.87(-0.03)(+0.02) keV. The other is a recombining plasma (RP) component of lighter elements with kTe = 0.46 +/- 0.03 keV, initial temperature kTinit = 3 keV (fixed), and ionization parameter net = (6.1(-0.4) (0.5)) x 10(11) cm(-3) s. As the formation process of the recombining plasma, both rarefaction and thermal conduction scenarios are considered. The former would not be favored since we found the recombining plasma only in the northeastern region, whereas the latter would explain the origin of the RP. In the latter scenario, an RP is anticipated where blast waves in part of the remnant are in contact with cool dense gas. The emission measure suggests higher ambient gas density in the northeastern region. The morphology of the radio shell and a GeV gamma ray emission also suggest a molecular cloud in the region.
  • F. A. Aharonian; H. Akamatsu; F. Akimoto; S. W. Allen; L. Angelini; K. A. Arnaud; M. Audard; H. Awaki; M. Axelsson; A. Bamba; M. W. Bautz; R. D. Blandford; E. Bulbul; L. W. Brenneman; G. V. Brown; E. M. Cackett; M. Chernyakova; M. P. Chiao; P. Coppi; E. Costantini; J. de Plaa; J. -W. den Herder; C. Done; T. Dotani; K. Ebisawa; M. E. Eckart; T. Enoto; Y. Ezoe; A. C. Fabian; C. Ferrigno; A. R. Foster; R. Fujimoto; Y. Fukazawa; A. Furuzawa; M. Galeazzi; L. C. Gallo; P. Gandhi; M. Giustini; A. Goldwurm; L. Gu; M. Guainazzi; Y. Haba; K. Hagino; K. Hamaguchi; I. Harrus; I. Hatsukade; K. Hayashi; T. Hayashi; K. Hayashida; J. Hiraga; A. E. Hornschemeier; A. Hoshino; J. P. Hughes; Y. Ichinohe; R. Iizuka; H. Inoue; S. Inoue; Y. Inoue; K. Ishibashi; M. Ishida; K. Ishikawa; Y. Ishisaki; M. Itoh; M. Iwai; N. Iyomoto; J. S. Kaastra; T. Kallman; T. Kamae; E. Kara; J. Kataoka; S. Katsuda; J. Katsuta; M. Kawaharada; N. Kawai; R. L. Kelley; D. Khangulyan; C. A. Kilbourne; A. L. King; T. Kitaguchi; S. Kitamoto; T. Kitayama; T. Kohmura; M. Kokubun; S. Koyama; K. Koyama; P. Kretschmar; H. A. Krimm; A. Kubota; H. Kunieda; P. Laurent; F. Lebrun; S. -H. Lee; M. A. Leutenegger; O. Limousin; M. Loewenstein; K. S. Long; D. H. Lumb; G. M. Madejski; Y. Maeda; D. Maier; K. Makishima; M. Markevitch; H. Matsumoto; K. Matsushita; D. McCammon; B. R. McNamara; M. Mehdipour; E. D. Miller; J. M. Miller; S. Mineshige; K. Mitsuda; I. Mitsuishi; T. Miyazawa; T. Mizuno; H. Mori; K. Mori; H. Moseley; K. Mukai; H. Murakami; T. Murakami; R. F. Mushotzky; T. Nakagawa; H. Nakajima; T. Nakamori; T. Nakano; S. Nakashima; K. Nakazawa; K. Nobukawa; M. Nobukawa; H. Noda; M. Nomachi; S. L. O'Dell; H. Odaka; T. Ohashi; M. Ohno; T. Okajima; N. Ota; M. Ozaki; F. Paerels; S. Paltani; A. Parmar; R. Petre; C. Pinto; M. Pohl; F. S. Porter; K. Pottschmidt; B. D. Ramsey; C. S. Reynolds; H. R. Russell; S. Safi-Harb; S. Saito; K. Sakai; H. Sameshima; T. Sasaki; G. Sato; K. Sato; R. Sato; M. Sawada; N. Schartel; P. J. Serlemitsos; H. Seta; M. Shidatsu; A. Simionescu; R. K. Smith; Y. Soong; L. Stawarz; Y. Sugawara; S. Sugita; A. E. Szymkowiak; H. Tajima; H. Takahashi; T. Takahashi; S. Takeda; Y. Takei; T. Tamagawa; K. Tamura; T. Tamura; T. Tanaka; Yasuo Tanaka; Yasuyuki Tanaka; M. Tashiro; Y. Tawara; Y. Terada; Y. Terashima; F. Tombesi; H. Tomida; Y. Tsuboi; M. Tsujimoto; H. Tsunemi; T. Tsuru; H. Uchida; H. Uchiyama; Y. Uchiyama; S. Ueda; Y. Ueda; S. Ueno; S. Uno; C. M. Urry; E. Ursino; C. P. de Vries; S. Watanabe; N. Werner; D. R. Wik; D. R. Wilkins; B. J. Williams; S. Yamada; H. Yamaguchi; K. Yamaoka; N. Y. Yamasaki; M. Yamauchi; S. Yamauchi; T. Yaqoob; Y. Yatsu; D. Yonetoku; A. Yoshida; I. Zhuravleva; A. Zoghbi
    ASTROPHYSICAL JOURNAL LETTERS IOP PUBLISHING LTD 837 (1) L15  2041-8205 2017/03 [Refereed]
     
    X-ray spectroscopy with Hitomi was expected to resolve the origin of the faint unidentified E approximate to 3.5 keV emission line reported in several low-resolution studies of various massive systems, such as galaxies and clusters, including the Perseus cluster. We have analyzed the Hitomi first-light observation of the Perseus cluster. The emission line expected for Perseus based on the XMM-Newton signal from the large cluster sample under the dark matter decay scenario is too faint to be detectable in the Hitomi data. However, the previously reported 3.5 keV flux from Perseus was anomalously high compared to the sample-based prediction. We find no unidentified line at the reported high flux level. Taking into account the XMM measurement uncertainties for this region, the inconsistency with Hitomi is at a 99% significance for a broad dark matter line and at 99.7% for a narrow line from the gas. We do not find anomalously high fluxes of the nearby faint K line or the Ar satellite line that were proposed as explanations for the earlier 3.5 keV detections. We do find a hint of a broad excess near the energies of high-n transitions of S XVI (E similar or equal to 3.44 keV rest-frame)-a possible signature of charge exchange in the molecular nebula and another proposed explanation for the unidentified line. While its energy is consistent with XMM pn detections, it is unlikely to explain the MOS signal. A confirmation of this interesting feature has to wait for a more sensitive observation with a future calorimeter experiment.
  • K. K. Nobukawa; M. Nobukawa; S. Yamauchi; H. Uchiyama; K. Koyama
    Proceedings of Science 2017/01 
    Cosmic rays (CRs) in our galaxy are thought to be generated via diffusive shock acceleration. Gamma-ray observations have revealed that protons and/or electrons are accelerated to energies up to 100 TeV in supernova remnants (SNRs), and hence SNRs are the most plausible source of CR production. Whereas low-energy cosmic rays (LECRs) below the MeV band have important information on the initial acceleration mechanism, there has been very little information on LECRs due to lack of an effective probe. By interacting with neutral iron atoms in the interstellar medium, LECRs produce fluorescent X-ray line emission at 6.40 keV. The 6.40 keV line obser-vation can be a probe to investigate LECRs. The Suzaku data analysis discovered the 6.40 keV line emission from several SNRs interacting with molecular clouds (W28, Kes 67, Kes 69, Kes 78, Kes 79, W44 and 3C391). The 6.40 keV line emission would be produced by MeV protons with the energy density of > 10-100 eV cm-3. Furthermore, we discovered the 6.40 keV line emission from a giant molecular cloud located near the Galactic center. The energy density of MeV protons is estimated to be ∼80 eV cm-3. The diffusion length of MeV protons is very short, and thus the MeV protons should be produced in situ. Surprisingly, there is no SNR in the vicinity. The LECRs would possibly be generated by stochastic acceleration via Alfvén turbulence.
  • Masayoshi Nobukawa; Hideki Uchiyama; Kumiko K. Nobukawa; Shigeo Yamauchi; Katsuji Koyama
    ASTROPHYSICAL JOURNAL IOP PUBLISHING LTD 833 (2) 268  0004-637X 2016/12 [Refereed]
     
    This paper reports detailed K-shell line profiles of iron (Fe) and nickel (Ni) of the Galactic Center X-ray Emission (GCXE), Galactic Bulge X-ray Emission (GBXE), Galactic Ridge X-ray Emission (GRXE), magnetic Cataclysmic Variables (mCVs), non-magnetic Cataclysmic Variables (non-mCVs), and coronally Active Binaries (ABs). For the study of the origin of the GCXE, GBXE, and GRXE, the spectral analysis is focused on equivalent widths of the Fe I-K alpha, Fe XXV-He alpha, and Fe XXVI-Ly alpha. lines. The global spectrum of the GBXE is reproduced by a combination of the mCVs, non-mCVs, and ABs spectra. On the other hand, the GRXE spectrum shows significant data excesses at the Fe I-Ka and Fe XXV-Hea. line energies. This means that additional components other than mCVs, non-mCVs, and ABs are required, which have symbiotic phenomena of cold gas and very high-temperature plasma. The GCXE spectrum shows larger excesses than those found in the GRXE spectrum at all the K-shell lines of iron and nickel. Among them the largest ones are the Fe I-K alpha, Fe XXV-He alpha, Fe XXVI-Ly alpha, and Fe XXVI-Ly beta. lines. Together with the fact that the scale heights of the Fe I-K alpha, Fe XXV-He alpha, and Fe XXVI-Ly alpha lines are similar to that of the central molecular zone (CMZ), the excess components would be related to high-energy activity in the extreme envelopment of the CMZ.
  • Shota Inoue; Kiyoshi Hayashida; Shuhei Katada; Hiroshi Nakajima; Ryo Nagino; Naohisa Anabuki; Hiroshi Tsunemi; Takeshi Go Tsuru; Takaaki Tanaka; Hiroyuki Uchida; Masayoshi Nobukawa; Kumiko Kawabata Nobukawa; Ryosaku Washino; Koji Mori; Eri Isoda; Miho Sakata; Takayoshi Kohmura; Koki Tamasawa; Shoma Tanno; Yuma Yoshino; Takahiro Konno; Shutaro Ueda
    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT ELSEVIER SCIENCE BV 831 415 - 419 0168-9002 2016/09 [Refereed]
     
    The ASTRO-H satellite is the 6th Japanese X-ray astronomical observatory to be launched in early 2016. The satellite carries four kinds of detectors, and one of them is an X-ray CCD camera, the soft X-ray imager (SXI), installed on the focal plane of an X-ray telescope. The SXI contains four CCD chips, each with an imaging area of 31 mm x 31 mm, arrayed in mosaic, covering the field-of-view of 38' x 38', the widest ever flown in orbit. The CCDs are a P-channel back-illuminated (BI) type with a depletion layer thickness of 200 um. We operate the CCDs in a photon counting mode in which the position and energy of each photon are measured in the energy band of 0.4-12 keV. To evaluate the X-ray spectra obtained with the SXI, an accurate calibration of its response function is essential. For this purpose, we performed calibration experiments at Kyoto and Photon Factory of KEK, each with different X-ray sources with various X-ray energies. We fit the obtained spectra with 5 components; primary peak, secondary peak, constant tail, Si escape and Si fluorescence, and then model their energy dependence using physics based or empirical formulae. Since this is the first adoption of P -channel BI -type CCDs on an X-ray astronomical satellite, we need to take special care on the constant tail component which is originated in partial charge collection. It is found that we need to assume a trapping layer at the incident surface of the CCD and implement it in the response model. In addition, the Si fluorescence component of the SXI response is significantly weak, compared with those of front -illuminated type CCDs. (C) 2016 Elsevier B.V. All rights reserved.
  • Shigeo Yamauchi; Kumiko K. Nobukawa; Masayoshi Nobukawa; Hideki Uchiyama; Katsuji Koyama
    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN OXFORD UNIV PRESS 68 (4) 59  0004-6264 2016/08 [Refereed]
     
    This paper reports the analysis of the X-ray spectra of the Galactic diffuse X-ray emission (GDXE) in the Suzaku archive. The fluxes of the Fe I K alpha (6.4 keV), Fe XXV He alpha (6.7 keV), and Fe XXVI Ly alpha (6.97 keV) lines are separately determined. From the latitude distributions, we confirm that the GDXE is decomposed into the Galactic center (GCXE), the Galactic bulge (GBXE) and the Galactic ridge (GRXE) X-ray emissions. The scale heights (SHs) of the Fe XXV He alpha line of the GCXE, GBXE, and GRXE are determined to be similar to 40, similar to 310, and similar to 140 pc, while those of the Fe I K alpha line are similar to 30, similar to 160, and similar to 70 pc, respectively. The mean equivalent widths (EWs) of the sum of the Fe XXV He alpha and Fe XXVI Lya lines are similar to 750 eV, similar to 600 eV, and similar to 550 eV, while those of the Fe I K alpha line are similar to 150 eV, similar to 60 eV, and similar to 100 eV for the GCXE, GBXE, and GRXE, respectively. The origin of the GBXE, GRXE, and GCXE is separately discussed based on the new results of the SHs and EWs, in comparison with those of the cataclysmic variables, active binaries and coronal active stars.
  • Ryosaku Washino; Hiroyuki Uchida; Masayoshi Nobukawa; Takeshi Go Tsuru; Takaaki Tanaka; Kumiko Kawabata Nobukawa; Katsuji Koyama
    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN OXFORD UNIV PRESS 68 (SP1) S4  0004-6264 2016/06 [Refereed]
     
    We report on Suzaku results concerning Kes 17, a Galactic mixed-morphology supernova remnant. The X-ray spectrum of the whole Kes 17 is well explained by a pure thermal plasma, in which we found Ly alpha of Al XIII and He alpha of Al XII, Ar XVII, and Ca XIX lines for the first time. The abundance pattern and the plasma mass suggest that Kes 17 is a remnant of a core-collapsed supernova of a 25-30 M-circle dot progenitor star. The X-ray spectrum of the north region is expressed by a recombining plasma. The origin would be due to the cooling of electrons by thermal conduction to molecular clouds located near the north region.
  • Hiroshi Tsunemi; Kiyoshi Hayashida; Takeshi Go Tsuru; Tadayasu Dotani; Hiroshi Nakajima; Naohisa Anabuki; Ryo Nagino; Takaaki Tanaka; Hiroyuki Uchida; Masanobu Ozaki; Chikara Natsukari; Hiroshi Tomida; Shutaro Ueda; Masachika Iwai; Masayoshi Nobukawa; Junko S. Hiraga; Takayoshi Kohmura; Hiroshi Murakami; Koji Mori; Makoto Yamauchi; Isamu Hatsukade; Yusuke Nishioka; Aya Bamba; Kumiko K. Nobukawa; John Doty
    SPACE TELESCOPES AND INSTRUMENTATION 2016: ULTRAVIOLET TO GAMMA RAY SPIE-INT SOC OPTICAL ENGINEERING 9905 10  0277-786X 2016 [Refereed]
     
    We report here the performance of the SXI on ASTRO-H that was started its operation from March, 02 2016. The SXI consists of 4 CCDs that cover 38' x 38' sky region. They are P-channel back-illumination type CCD with a depletion layer of 200 mu m. Charge injection (CI) method is applied from its beginning of the mission. Two single stage sterling coolers are equipped with the SXI while one of them has enough power to cool the CCD to -120 degrees C. There are two issues in the SXI performance: one is a light-leak and the other is a cosmic-ray echo. The light-leak is due to the fact that the day-Earth irradiates visible lights onto the SXI body through holes in the satellite base plate. It can be avoided by selecting targets not on the anti-day-Earth direction. The cosmic-ray echo is due to the improper parameter values that is fixed by revising them with which the cosmic-ray echo does not affect the image. Using the results of RXJ1856.5-3754, we confirm that the possible contaminants on the CCD is well within our expectation.
  • Tadayuki Takahashi; Motohide Kokubun; Kazuhisa Mitsuda; Richard Kelley; Takaya Ohashi; Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steve Allen; Naohisa Anabuki; Lorella Angelini; Keith Arnaud; Makoto Asai; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Philipp Azzarello; Chris Baluta; Aya Bamba; Nobutaka Bando; Marshall Bautz; Thomas Bialas; Roger Blandford; Kevin Boyce; Laura Brenneman; Greg Brown; Esra Bulbul; Edward Cackett; Edgar Canavan; Maria Chernyakova; Meng Chiao; Paolo Coppi; Elisa Costantini; Jelle De Plaa; Jan Willem Den Herder; Michael DiPirro; Chris Done; Tadayasu Dotani; John Doty; Ken Ebisawa; Megan Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew Fabian; Carlo Ferrigno; Adam Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi Gallo; Poshak Gandhi; Kirk Gilmore; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Daniel Haas; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Atsushi Harayama; Ilana Harrus; Isamu Hatsukade; Takayuki Hayashi; Katsuhiro Hayashi; Kiyoshi Hayashida; Junko Hiraga; Kazuyuki Hirose; Ann Hornschemeier; Akio Hoshino; John Hughes; Yuto Ichinohe; Ryo Iizuka; Yoshiyuki Inoue; Hajime Inoue; Kazunori Ishibashi; Manabu Ishida; Kumi Ishikawa; Kosei Ishimura; Yoshitaka Ishisaki; Masayuki Itoh; Naoko Iwata; Naoko Iyomoto; Chris Jewell; Jelle Kaastra; Timothy Kallman; Tuneyoshi Kamae; Erin Kara; Jun Kataoka; Satoru Katsuda; Junichiro Katsuta; Madoka Kawaharada; Nobuyuki Kawai; Taro Kawano; Shigeo Kawasaki; Dmitry Khangulyan; Caroline Kilbourne; Mark Kimball; Ashley King
    Proceedings of SPIE - The International Society for Optical Engineering 9905 0277-786X 2016 
    © 2016 SPIE. The Hitomi (ASTRO-H) mission is the sixth Japanese X-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E > 2 keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decades in energy from soft X-rays to gamma-rays. After a successful launch on 2016 February 17, the spacecraft lost its function on 2016 March 26, but the commissioning phase for about a month provided valuable information on the on-board instruments and the spacecraft system, including astrophysical results obtained from first light observations. The paper describes the Hitomi (ASTRO-H) mission, its capabilities, the initial operation, and the instruments/spacecraft performances confirmed during the commissioning operations for about a month.
  • Masayoshi Nobukawa; Hideki Uchiyama; Kumiko K. Nobukawa; Shigeo Yamauchi; Katsuji Koyama
    Proceedings of the International Astronomical Union Cambridge University Press 11 206 - 207 1743-9221 2016 
    An unresolved X-ray emission extends along the Galactic plane, so-called the Galactic diffuse X-ray emission (GDXE). The characteristic feature is three K-shell lines of Fe at 6.4, 6.7, and 6.9 keV. Recently, superposition of faint point sources, such as Cataclysmic variables (CVs) and Active binaries (ABs) is thought to be a major origin, although it is under debate which sub-class mostly contribute. We re-analyzed the Suzaku archive data and constructed spectral models of ABs, magnetic CVs (mCVs), and non-magnetic CVs (non-mCVs). The GBXE is explained by combination of those models non-mCVs and ABs mainly contribute while mCVs account for ∼10% or less of the 5-10 keV flux. On the other hand, the GCXE and GRXE spectra cannot be represented by any combination of the point sources, indicating another origin would be required.
  • V. A. Dogiel; D. O. Chernyshov; A. M. Kiselev; M. Nobukawa; K. S. Cheng; C. Y. Hui; C. M. Ko; K. K. Nobukawa; T. G. Tsuru
    ASTROPHYSICAL JOURNAL IOP PUBLISHING LTD 809 (1) 48  0004-637X 2015/08 [Refereed]
     
    From the rate of hydrogen ionization and the gamma-ray flux, we derived the spectrum of relativistic and subrelativistic cosmic rays (CRs) nearby and inside the molecular cloud Sgr B2 near the Galactic Center. We studied two cases of CR propagation in molecular clouds: free propagation and scattering of particles by magnetic fluctuations excited by the neutral gas turbulence. We showed that in the latter case CR propagation inside the cloud can be described as diffusion with a coefficient of similar to 3 x 10(27) cm(2) s(-1). For the case of hydrogen ionization by subrelativistic protons, we showed that their spectrum outside the cloud is quite hard with a spectral index of delta > -1. The energy density of subrelativistic protons (>50 eV cm(-3)) is one order of magnitude higher than that of relativistic CRs. These protons generate the 6.4 keV emission from Sgr B2, which was about 30% of the flux observed by Suzaku in 2013. Future observations for the period after 2013 may discover the background flux generated by subrelativistic CRs in Sgr B2. Alternatively, hydrogen ionization of the molecular gas in Sgr B2 may be caused by high energy electrons. We showed that the spectrum of electron bremsstrahlung is harder than the observed continuum from Sgr B2, and in principle, this X-ray component provided by electrons could be seen from the INTEGRAL data as a stationary high energy excess above the observed spectrum E-x(-2).
  • K. K. Nobukawa; M. Nobukawa; H. Uchiyama; T. G. Tsuru; K. Torii; T. Tanaka; D. O. Chernyshov; Y. Fukui; V. A. Dogiel; K. Koyama
    ASTROPHYSICAL JOURNAL LETTERS IOP PUBLISHING LTD 807 (1) L10  2041-8205 2015/07 [Refereed]
     
    A common idea for the origin of the Galactic diffuse X-ray emission, particularly that of the iron lines from neutral and highly ionized atoms, is a superposition of many cataclysmic variables and coronally active binaries. In this scenario, the flux should symmetrically distribute between the east and west on the plane with respect to Sagittarius A* because the stellar mass distribution determined by infrared observations is nearly symmetric. This symmetry is confirmed for the highly ionized iron line as well as the continuum emission. However, a clear excess of the neutral iron line in the near east of the Galactic center compared to the near-west side is found. The flux distribution of the excess emission well correlates with the molecular column density. The X-ray spectrum of the excess emission is described by a power-law continuum plus a 6.4 keV line with a large equivalent width of similar to 1.3 keV, which is hardly explained by the low-energy electron bombardment scenario. The longitudinal and latitudinal distribution of the excess emission disfavors the X-ray irradiation, either by Sagittarius A* or by nearby X-ray binaries. Then, the low-energy proton bombardment is the most probable origin, although the high-energy density similar to 80 eV cm(-3) in 0.1-1000 MeV is required and there is no conventional proton source in the vicinity.
  • K. K. Nobukawa; M. Nobukawa; T. G. Tsuru; K. Koyama
    ADVANCES IN SPACE RESEARCH ELSEVIER SCI LTD 55 (11) 2493 - 2499 0273-1177 2015/06 [Refereed]
     
    HESS J1841-055 is a diffuse unidentified gamma-ray source with the size of similar to 1 degrees.3 x 1 degrees. No conclusive counterpart in other wavelengths has so far detected. To search for X-rays responsible for the TeV emission, the Suzaku observations were conducted, which covered a half region of the HESS source. In the soft band (0.5-2.0 keV), we discovered a diffuse emission, Suzaku J1840.2-0552, with the size of similar to 10'. Since its spectrum was fitted by an optically thin thermal plasma model, Suzaku J1840.2-0552 is likely to be a supernova remnant. We also discovered an extended source, Suzaku J1840.2-0544, in the hard band (2.0-8.0 keV) with an emission line at 6.1 keV. From the spectral feature and large interstellar absorption, this source is likely to be a cluster of galaxies behind the Galactic plane at the red-shift of similar to 0.09. The other diffuse source spatially overlaps with the SNR candidate G26.6-0.2, which shows a non-thermal dominant spectrum. Since no other candidate is found in the hard X-ray band, we infer that these largely extended sources could be possible counterparts of HESS J1841-055. (C) 2015 COSPAR. Published by Elsevier Ltd. All rights reserved.
  • Masayoshi Nobukawa; Kumiko K. Nobukawa
    Proceedings of the XI Multifrequency Behaviour of High Energy Cosmic Sources Workshop (MULTIF15). 25-30 May 2015. Palermo, Italy. id.28  2015/01 [Refereed]
     
    There exists an unresolved X-ray emission component, that extends along the Galactic plane, and called the Galactic ridge X-ray emission (GRXE). The GRXE spectrum exhibits prominent Fe K-shell lines at 6.4, 6.7, and 7.0 keV. Approximately 80% of the Fe line flux has recently been resolved into point sources; hence, a superposition of faint point sources is now considered to be the dominant origin of the GRXE. However, the remaining portion of the flux is still under debate. Therefore, we investigated longitudinal distributions of the Fe lines in l < 4° with Suzaku, and discovered an asymmetrical profile in the 6.4-keV line intensity, which is contrary to the symmetrical behavior of the 6.7 keV line. The excess of the 6.4 keV line intensity in l = 1°.5-4° is associated with the12CO intensity, which consists of a hard continuum and a 6.4 keV line with an equivalent width of 1.3±0.4 keV. These results indicate that the 6.4 keV excess is difficult to explain using the integration of faint point sources; the excess is probably emitted from the dense interstellar medium due to the bombardment of low-energy cosmic-ray protons with energy density of ∼80 eV cm-3. No canonical accelerator, such as a supernova remnant or a pulsar wind nebula, can be found in the vicinity. One possible mechanism would be stochastic acceleration by Alfvénic turbulence in interstellar space.
  • Koyama, K; Kataoka, J; Nobukawa, M; Uchiyama, H; Nakashima, S; Aharonian, F; Chernyakova, M; Ichinohe, Y; Nobukawa, K. K; Maeda, Y; Matsumoto, H; Murakami, H; Ricci, C; Stawarz, L; Tanaka, T; Tsuru, T. G; Watanabe, S; Yamauchi, S; Yuasa, T; for the ASTRO-H; Science Working Group
    eprint arXiv 1412.1170 eprint arXiv 2014/12
  • Kumiko Kawabata Nobukawa; Takeshi Go Tsuru; Masayoshi Nobukawa; Takaaki Tanaka; Hiroyuki Uchida; Hiroshi Tsunemi; Kiyoshi Hayashida; Naohisa Anabuki; Hiroshi Nakajima; Ryo Nagino; Tadayasu Dotani; Masanobu Ozaki; Chikara Natsukari; Hiroshi Tomida; Masashi Kimura; Makoto Yamauchi; Koji Mori; Isamu Hatsukade; Yusuke Nishioka; Takayoshi Kohmura; Junko Sato Hiraga; Hiroshi Murakami
    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT ELSEVIER SCIENCE BV 765 269 - 274 0168-9002 2014/11 [Refereed]
     
    We are developing the Soft X-ray Imager (SXI), a charge-coupled device (CCD) camera system to be deployed onboard the ASTRO-H satellite. Using an engineering model system in which design specifications were the same as those of the flight model, we measured charge transfer inefficiency (ETU and the effects of charge [railing. The CCD was irradiated with monochromatic X-rays produced by a radio isotope (Fe-55) and X-ray generator using alpha particles from Am-241. We used four targets for the X-ray generator: (C2F4)(n), SiO2, Ti, and Ge. Since CTl degrades energy resolution, we adopted the charge-injection technique to the SM. With this technique, injected charges till traps, and subsequent signal charges are transferred with less loss of charge. However, the charge-injection technique can cause positional variations in gain on the CCD chip. Thus, we constructed a method for correcting CTl. We also evaluated the charge trailing effect and tested a method for correcting its effects. After applying these corrections to charge injection, variations in gain improved from 0.5% to 0.1% over the CCD chip, and the energy resolution (FWHM) improved from similar to 220 eV to similar to 180 eV at 5.9 KeV. (C) 2014 Elsevier B.V. All rights reserved,
  • Use of a Charge-Injection Technique to Improve Performance of the Soft X-ray Imager aboard ASTRO-H
    Nobukawa K. Kumiko; Tsuru T. Go; Nobukawa Masahiro; Tanaka Takaaki; Uchida Hiroyuki
    Proceedings of a conference on "Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe" 196 - 197 2014/09
  • New Correction Method for CTI and Charge Trail of the Soft X-ray Imager onboard ASTRO-H
    K. K. Nobukawa; T. G. Tsuru; M. Nobukawa; T. Tanaka; H. Uchida; H. Tsunemi; K. Hayashida; N. Anabuki; H. Nakajima; R. Nagino; T. Dotani; M. Ozaki; H. Tomida; C. Natsukari; M. Kimura; M. Yamauchi; K. Mori; I. Hatsukade; Y. Nishioka; T. Kohmura; J. S. Hiraga; H. Murakami on; behalf of; the; SXI team
    Proceedings of a conference on Suzaku-MAXI 2014: Expanding the frontiers of the X-ray universe 196 - 197 2014
  • Kiyoshi Hayashida; Hiroshi Tsunemi; Takeshi Go Tsuru; Tadayasu Dotani; Hiroshi Nakajima; Naohisa Anabuki; Ryo Nagino; Shutaro Ueda; Takaaki Tanaka; Hiroyuki Uchida; Masayoshi Nobukawa; Masanobu Ozaki; Chikara Natsukari; Junko S. Hiraga; Hiroshi Tomida; Masashi Kimura; Takayoshi Kohmura; Hiroshi Murakami; Koji Mori; Makoto Yamauchi; Isamu Hatsukade; Yusuke Nishioka; Aya Bamba; Shuhei Katada; Kumiko Kawabata Nobukawa; Masachika Iwai; Keisuku Kondo; Tukasa Takeyoshi; John P. Doty
    SPACE TELESCOPES AND INSTRUMENTATION 2014: ULTRAVIOLET TO GAMMA RAY SPIE-INT SOC OPTICAL ENGINEERING 9144 0277-786X 2014 
    Soft X-ray Imager (SXI) is a CCD camera onboard the ASTRO-H satellite which is scheduled to be launched in 2015. The SXI camera contains four CCD chips, each with an imaging area of 31 mm x31 mm, arrayed in mosaic, covering the whole FOV area of 38' x 38'. The CCDs are a P-channel back-illuminated (BI) type with a depletion layer thickness of 200 pm. High QE of 77% at 10 keV expected for this device is an advantage to cover an overlapping energy band with the Hard X-ray Imager (HXI) onboard ASTRO-H. Most of the flight components of the SXI system are completed until the end of 2013 and assembled, and an end-to-end test is performed. Basic performance is verified to meet the requirements. Similar performance is confirmed in the first integration test of the satellite performed in March to June 2014, in which the energy resolution at 5.9 keV of 160 eV is obtained. In parallel to these activities, calibrations using engineering model CCDs are performed, including QE, transmission of a filter, linearity, and response profiles.
  • NOBUKAWA Kumiko Kawabata; NOBUKAWA Masayoshi; TSURU Takeshi Go; KOYAMA Katsuji
    Publications of the Astronomical Society of Japan Astronomical Society of Japan 64 (5) 99  0004-6264 2012/10 [Refereed]
  • Kumiko Kawabata; Masayoshi Nobukawa; Takeshi Go Tsuru; Katsuji Koyama
    SUZAKU 2011: EXPLORING THE X-RAY UNIVERSE: SUZAKU AND BEYOND AMER INST PHYSICS 1427 310  0094-243X 2012 
    We observed the supergiant fast X-ray transient (SFXT) AX J1841.0-0536 with Suzaku. Many short flares with durations of similar to 100 s were detected in the XIS and HXD bands. We found that the overall spectrum in the 1.0-40 keV band was fitted with an partially absorbed cut-off power-law plus an Fe I K alpha line and an absorption feature at the center energy of similar to 15 keV, that we interpret as possible evidence of a resonant cyclotron absorption feature. We then made time-resolved spectra and fit them with the same models as the overall spectrum. The photon indices of the power-law were distributed in 0-2 with the trend of "harder when brighter". On the other hand, no significant difference was found, either in the absorption column densities nor in the covering fractions between any of the phases.

Conference Activities & Talks

  • ISS曝露部搭載のX線SOI-CMOSピクセル検出器XRPIXで探る超高層大気の観測計画  [Not invited]
    信川久実子; 武田彩希; 勝田哲; 鶴剛; 中澤知洋; 森浩二; 信川正順; 内田裕之; 眞方恒陽; 河邉圭寿; 岸本拓海; 黒木瑛介; 桒野慧
    日本物理学会 第78回年次大会（2023年）  東北大学
  • Suzaku Observations of Fe K-shell Lines in the Supernova Remnant W51C and Hard X-ray Sources in the Proximity  [Invited]
    Kumiko Nobukawa
    Multifrequency Behaviour of High Energy Cosmic Sources - XIV  Palermo
  • XRISM observations of the GC  [Invited]
    Kumiko Nobukawa
    Galactic Center Workshop 2023  Granada
  • X線分光撮像衛星(XRISM) 搭載軟X線撮像装置(Xtend) の開発の現状(9)  [Not invited]
    信川久実子; 森浩二; 冨田洋; 中嶋大; 野田博文; 林田清; 鈴木寛大; 小林翔悟; 内田裕之; 萩野浩一; 青木悠馬; 伊藤耶馬斗; 金丸善朗; 宮崎啓太郎; 楠康平; 大塚芳徳; 横須晴彦; 米丸若菜; 市川雄大; 中野瑛子; 中村彰太郎; 亀井貴光; 朝倉一統; 善本真梨那; 大出優一; 佐藤淳矢; 袴田知宏; 青柳美緒; 角町駿; 土居俊輝; 青木大輝; 藤澤海斗; 清水康行; 畠中大介; 田中孝明; 村上弘志; 信川正順; 内山秀樹; 吉田鉄生; 米山友景; 幸村孝由; 鶴剛; 松本浩典; Takashi Okajima; 石田学; 前田良知; 山内誠; 廿日出勇; 平賀純子; 山岡和貴; 尾崎正伸; 堂谷忠靖; 常深博; 他 XRISM; end チーム
    日本天文学会2023年春季年会  立教大学
  • 超小型衛星で探る銀河系中心・銀河面からの鉄輝線
    信川久実子; 鶴剛; 信川正順
    2040年代のスペース天文学  2022/11
  • 次期X線天文衛星XRISMで探る天の川銀河に広がるX線放射
    信川久実子
    天の川銀河研究会2022  2022/11
  • 信川久実子
    公益財団法人 山田科学振興財団 2022年度研究交歓会  2022/10
  • 超新星残骸3C396における鉄K輝線の調査
    信川久実子; 神農夕奈
    日本天文学会2022年秋季年会  2022/09
  • 低エネルギー宇宙線起源の中性鉄輝線探査と今後の展望  [Invited]
    信川久実子
    SNR Workshop 2022  2022/03
  • SwiftとすざくによるMAXI J1421-613のダスト散乱エコーの観測  [Not invited]
    信川久実子; 信川正順; 山内茂雄
    日本天文学会2022年春季年会  2022/03
  • 中性鉄輝線で探る低エネルギー宇宙線  [Invited]
    信川久実子
    低エネルギー宇宙線ワークショップ  2021/03
  • Discovery of annular X-ray emission centered on MAXI J1421-613: Dust-scattering X-rays?  [Not invited]
    K. K. Nobukawa; M. Nobukawa; S. Yamauchi
    43rd COSPAR Scientific Assembly  2021/01
  • 30 Doradus複合領域における中性鉄輝線の調査 (2)  [Not invited]
    信川久実子; 山内茂雄; 信川正順; 佐野栄俊; 柘植紀節; 藤田裕
    日本天文学会2020年春季年会  2020/03
  • Measurements of low-energy cosmic rays  [Invited]
    Kumiko K. Nobukawa
    GCWS2019: New Horizons in Galactic Center Astronomy and Beyond  2019/10
  • 30 Doradus複合領域における中性鉄輝線の調査  [Not invited]
    信川 久実子
    日本天文学会2019年秋季年会  2019/09
  • MeV 宇宙線の研究とMeVガンマ線との関連  [Invited]
    信川 久実子
    第二回MeVガンマ線天文学研究会  2019/09
  • Low-energy cosmic rays in supernova remnants interacting with molecular clouds  [Invited]
    Kumiko K. Nobukawa
    Multifrequency Behaviour of High Energy Cosmic Sources - XIII  2019/06
  • X線分光撮像衛星(XRISM)搭載Xtend用試作miniCCDにおけるCTIモデル  [Not invited]
    信川 久実子
    日本天文学会2019年春季年会  2019/03
  • 中性鉄輝線で探る超新星残骸における低エネルギー宇宙線  [Not invited]
    信川 久実子
    第18回高宇連研究会  2019/03
  • Observations of Neutral Iron Line in Supernova Remnants and Implications for Low-energy Cosmic Rays  [Not invited]
    Kumiko K. Nobukawa
    SNR workshop 2018  2018/10
  • 6.4 keV鉄輝線を用いた超新星残骸におけるMeV宇宙線の測定  [Not invited]
    信川 久実子
    日本天文学会2018年秋季年会  2018/09
  • Measurement of low-energy cosmic rays via the neutral iron line  [Invited]
    Kumiko K. Nobukawa
    26th E+CRS/35th RCRC  2018/07  Altai State University
  • Measurement of low-energy cosmic rays in Supernova remnants via neutral iron line  [Not invited]
    Kumiko K. Nobukawa
    42nd COSPAR Scientific Assembly  2018/07
  • X線天文衛星「ひとみ」による超新星残骸N132Dの観測  [Invited]
    信川 久実子
    第17回高宇連研究会  2018/03
  • MAXI J1421−613 周辺からのX線円環放射の発見  [Not invited]
    信川 久実子
    日本天文学会2018年春季年会  2018/03
  • 銀河リッジX線放射の中性鉄輝線における低エネルギー宇宙線の寄与  [Not invited]
    信川 久実子
    天の川銀河研究会2017  2017/10
  • Low-Energy Cosmic Rays from Supernova Remnants  [Invited]
    Kumiko K. Nobukawa
    SNR workshop 2017  2017/09  Nagoya University
  • 分子雲と相互作用している超新星残骸における宇宙線起源の中性鉄輝線探査  [Not invited]
    信川 久実子
    日本天文学会2017年秋季年会  2017/09
  • First discovery of iron line emission generated by low-energy cosmic rays  [Not invited]
    Kumiko K. Nobukawa
    35th International Cosmic Ray Conference  2017/07  Busan
  • 超新星残骸における MeV 陽子起源の中性鉄輝線放射  [Not invited]
    信川 久実子
    日本天文学会2017年春季年会  2017/03
  • 銀河リッジX線放射の中性鉄輝線における宇宙線の寄与  [Not invited]
    信川 久実子
    日本天文学会2016年春季年会  2016/03
  • 銀河リッジX線放射における中性鉄輝線の研究: 低エネルギー宇宙線の寄与  [Not invited]
    信川 久実子
    高宇連第15回研究会・博士論文発表会  2016/03
  • 銀河リッジX線放射の6.4 keV輝線  [Not invited]
    信川 久実子
    日本天文学会2015年秋季年会  2015/09
  • Enhancement of the 6.4 keV line in the inner Galactic ridge: Proton-induced fluorescence?  [Not invited]
    Kumiko K. Nobukawa
    The Galactic center workshop 2015  2015/07  Nagoya University
  • The 6.4 keV line emission in the Galactic ridge: Proton-induced fluorescence?  [Not invited]
    Kumiko K. Nobukawa
    Japanese-Dutch bilateral workshop: Spectroscopy of Cosmic Plasma in the Era of ASTRO-H  2015/05
  • 3度領域における銀河リッジX線放射の中性鉄輝線の超過の発見  [Not invited]
    信川 久実子
    天の川銀河研究会2015  2015/03
  • 銀河面X線放射における中性鉄輝線放射の非対称性の発見  [Not invited]
    信川 久実子
    日本天文学会2014年秋季年会  2014/09
  • Suzaku Observation of the Unidentified Gamma-ray Source HESS J1841-055  [Not invited]
    Kumiko K. Nobukawa
    The 40th COSPAR Scientific Assembly  2014/08  Moscow
  • Discovery of excess fluorescence Fe emission in the 3-4 degree eastern region of the Galactic center: Evidence for cosmic-ray bombardment on interstellar gas?  [Not invited]
    Kumiko K. Nobukawa
    The 40th COSPAR Scientific Assembly  2014/08  Moscow
  • 銀河面X線放射における中性鉄輝線放射の非対称性の発見  [Not invited]
    信川 久実子
    銀河系中心部ワークショップ2014 -銀河面外に残された痕跡-  2014/05
  • ASTRO-H搭載 軟X線撮像検出器SXIにおけるCTIおよびCharge Trail補正  [Not invited]
    信川 久実子
    日本天文学会2014年春季年会  2014/03
  • New Correction Method for CTI and Charge Trail of the Soft X-ray Imager onboard ASTRO-H  [Not invited]
    Kumiko K. Nobukawa
    Suzaku-MAXI 2014, Expanding the Frontiers of the X-ray Universe  2014/02
  • ASTRO-H衛星搭載X線CCDカメラ （SXI） の地上較正実験とそれに用いるX線発生装置の製作  [Not invited]
    信川 久実子
    日本天文学会2013年秋季年会  2013/09
  • Performance Verification and Calibration of the Soft X-ray Imager (SXI) aboard ASTRO-H  [Not invited]
    Kumiko K. Nobukawa
    9th International “Hiroshima” Symposium on the Development and Application of Semiconductor Tracking Detectors  2013/09  Hiroshima
  • ASTRO-H搭載 軟X線撮像検出器 （SXI） : EMシステムを用いた性能評価と機能試験  [Not invited]
    信川 久実子
    日本天文学会2013年春季年会  2013/09
  • ASTRO-H搭載 軟X線撮像検出器 （SXI） : FPC熱サイクル試験  [Not invited]
    信川 久実子
    日本天文学会2012年秋季年会  2012/09
  • すざく衛星によるガンマ線未同定天体 HESS J1841-055の観測  [Not invited]
    河畠 久実子
    日本天文学会2012年春季年会  2012/03
  • すざく衛星によるガンマ線未同定天体 HESS J1841-055の観測  [Not invited]
    信川 久実子
    第12回宇宙科学シンポジウム  2012/01
  • すざく衛星による大質量X線連星系AX J1841.0-0536の観測  [Not invited]
    河畠 久実子
    日本天文学会2011年秋季年会  2011/09
  • Exploring the X-ray Universe: Suzaku and Beyond  [Not invited]
    Kumiko K. Nobukawa
    Exploring the X-ray Universe: Suzaku and Beyond  2011/06

MISC

  • 花岡真帆; 林田清; 野田博文; 米山友景; 朝倉一統; 岡崎貴樹; 佐久間翔太郎; 石倉彩美; 服部兼吾; 松本浩典; 金丸善朗; 佐藤仁; 高木駿亨; 寺田裕大; 住田知也; 森浩二; 齋藤真梨子; 信川久実子; 迫聖; 信川正順; 天野雄輝; 尾近洸行; 田中孝明; 内田裕之; 鶴剛; 樫村晶; 中嶋大; 冨田洋; 吉田鉄生; 卜部夕希乃; 平賀純子; 村上弘志; 内山秀樹; 小林翔悟; 萩野浩一; 幸村孝由; 山内誠; 廿日出勇; 山岡和貴; 尾崎正伸; 堂谷忠靖; 常深博  日本天文学会年会講演予稿集  2021-  2021
  • 冨田洋; 林田清; 森浩二; 中嶋大; 内田裕之; 鶴剛; 野田博文; 松本浩典; 常深博; 村上弘志; 山内誠; 廿日出勇; 幸村孝由; 萩野浩一; 小林翔悟; 田中孝明; 鈴木寛大; 岡島崇; 石田学; 前田良知; 堂谷忠靖; 尾崎正伸; 吉田鉄生; 米山友景; 内山秀樹; 山岡和貴; 信川正順; 信川久実子; 平賀純子  日本天文学会年会講演予稿集  2021-  2021
  • Nakazawa K.; Mori K.; Tsuru T. G.; Ueda Y.; Ishida M.; Matsumoto H.; Awaki H.; Murakami H.; Terada Y.; Kubota A.; Bamba A.; Odaka H.; Yatsu Y.; Kohmura T.; Hagino K.; Kobayashi S. B.; Uchiyama Y.; Kitayama T.; Takahashi T.; Watanabe S.; Iizuka R.; Yamaguchi H.; Ohashi T.; Nakajima M.; Furuzawa A.; Tanaka T.; Uchida H.; Noda H.; Tsunemi H.; Ito M.; Nobukawa M.; Nobukawa K.; Ota N.; Terashima Y.; Fukazawa Y.; Mizuno T.; Takahashi H.; Ohno M.; Takeda A.; Hornschemeier A. E.; Okajima T.; Zhang W. W.; Williams B. J.; the FORCE team  Meeting Abstracts of the Physical Society of Japan  75.1-  523  -523  2020
  • 金丸善朗; 佐藤仁; 高木駿亨; 寺田裕大; 住田知也; 森浩二; 齋藤真梨子; 信川久実子; 山内茂雄; 迫聖; 信川正順; 田中孝明; 内田裕之; 天野雄輝; 尾近洗行; 鶴剛; 花岡真帆; 米山友景; 岡崎貴樹; 朝倉一統; 佐久間翔太郎; 服部兼吾; 石倉彩美; 野田博文; 林田清; 松本浩典; 冨田洋; 樫村晶; 中嶋大; 卜部夕希乃; 平賀純子; 村上弘志; 内山秀樹; 山内誠; 廿日出勇; 幸村孝由; 萩野浩一; 小林翔悟; 山岡和貴; 堂谷忠靖; 尾崎正伸; 常深博  日本天文学会年会講演予稿集  2020-  2020
  • 迫聖; 信川正順; 齋藤真梨子; 信川久実子; 山内茂雄; 佐藤仁; 金丸善朗; 高木駿亨; 西岡祐介; 森浩二; 林田清; 冨田洋; 尾近洸行; 天野雄輝; 田中孝明; 内田裕之; 鶴剛; 樫村晶; 中嶋大; 米山友景; 岡崎貴樹; 朝倉一統; 花岡真帆; 服部兼吾; 佐久間翔太郎; 野田博文; 松本浩典; 常深博; 村上弘志; 内山秀樹; 山内誠; 廿日出勇; 幸村孝由; 萩野浩一; 小林翔悟; 山岡和貴; 卜部夕希乃; 平賀純子; 尾崎正伸; 堂谷忠靖  日本天文学会年会講演予稿集  2020-  2020
  • 内田裕之; 田中孝明; 鶴剛; 林田清; 冨田洋; 森浩二; 中嶋大; 松本浩典; 野田博文; 常深博; 村上弘志; 山内誠; 廿日出勇; 幸村孝由; 萩野浩一; 小林翔悟; 岡島崇; 石田学; 前田良知; 堂谷忠靖; 尾崎正伸; 内山秀樹; 山岡和貴; 信川正順; 信川久実子; 平賀純子  日本天文学会年会講演予稿集  2020-  2020
  • 齋藤真梨子; 信川久実子; 山内茂雄; 信川正順; 迫聖; 金丸善朗; 佐藤仁; 高木駿亨; 森浩二; 山内誠; 廿日出勇; 林田清; 野田博文; 松本浩典; 米山友景; 花岡真帆; 岡崎貴樹; 朝倉一統; 佐久間翔太郎; 服部兼吾; 石倉彩美; 常深博; 冨田洋; 田中孝明; 内田裕之; 天野雄輝; 尾近洸行; 鶴剛; 樫村晶; 中嶋大; 村上弘志; 内山秀樹; 幸村孝由; 萩野浩一; 小林翔悟; 山岡和貴; 卜部夕希乃; 平賀純子  日本天文学会年会講演予稿集  2020-  2020
  • 信川正順; 山内茂雄; 内山秀樹; 信川久実子; 村上弘志; 鶴剛; 前田良知; 野田博文  日本天文学会年会講演予稿集  2020-  2020
  • 金丸善朗; 佐藤仁; 高木駿亨; 寺田裕大; 住田知也; 森浩二; 齋藤真梨子; 山内茂雄; 信川久実子; 迫聖; 信川正順; 田中孝明; 内田裕之; 天野雄輝; 尾近洸行; 鶴剛; 花岡真帆; 米山友景; 岡崎貴樹; 朝倉一統; 佐久間翔太郎; 服部兼吾; 石倉彩美; 野田博文; 林田清; 松本浩典; 冨田洋; 吉田鉄生; 樫村晶; 中嶋大; 卜部夕希乃; 平賀純子; 村上弘志; 内山秀樹; 山内誠; 廿日出勇; 幸村孝由; 萩野浩一; 小林翔悟; 山岡和貴; 堂谷忠靖; 尾崎正伸; 常深博  日本天文学会年会講演予稿集  2020-  2020
  • Tanaka T.; Hayashida K.; Tomida H.; Mori K.; Uchida H.; Tsuru T. G.; Nakajima H.; Noda H.; Matsumoto H.; Okajima T.; Ishida M.; Maeda Y.; Murakami H.; Yamauchi M.; Hatsukade I.; Nobukawa M.; Nobukawa K. K.; Hagino K.; Kohmura T.; Kobayashi S.; Hiraga J. S.; Uchiyama H.; Yamaoka K.; Ozaki M.; Dotani T.; Tsunemi H.; the XRISM Xtend team  Meeting Abstracts of the Physical Society of Japan  2020-  533  -533  2020
  • 花岡真帆; 林田清; 野田博文; 岡崎貴樹; 米山友景; 朝倉一統; 佐久間翔太郎; 石倉彩美; 服部兼吾; 松本浩典; 金丸善朗; 佐藤仁; 高木駿亨; 寺田裕大; 住田知也; 森浩二; 齋藤真梨子; 信川久実子; 迫聖; 信川正順; 天野雄輝; 尾近洸行; 田中孝明; 内田裕之; 鶴剛; 樫村晶; 中嶋大; 冨田洋; 吉田鉄生; 卜部夕希乃; 平賀純子; 村上弘志; 内山秀樹; 小林翔悟; 萩野浩一; 幸村孝由; 山内誠; 廿日出勇; 山岡和貴; 尾崎正伸; 堂谷忠靖; 常深博  日本天文学会年会講演予稿集  2020-  2020
  • The astronomical herald
    信川 久実子  天文月報  112-  (8)  580  -581  2019/07
  • 信川 正順; 信川 久実子  天文月報 = The astronomical herald  112-  (6)  360  -362  2019/06
  • Kashimura H.; Nakajima H.; Tomida H.; Arai Y.; Hayashida K.; Noda H.; Matsumoto H.; Tsunemi H.; Tanaka T.; Uchida H.; Tsuru T. G.; Mori K.; Ozaki M.; Dotani T.; Yamauchi M.; Hatsukade I.; Murakami H.; Nobukawa M.; Nobukawa K. K.; Kohmura T.; Hagino K.; Kobayashi S.; Hiraga J. S.; Uchiyama H.; Yamaoka K.; the XRISM Xtend  Meeting Abstracts of the Physical Society of Japan  74.2-  410  -410  2019
  • Mori K.; Hayashida K.; Tomida H.; Tanaka T.; Uchida H.; Tsuru T. G.; Nakajima H.; Noda H.; Matsumoto H.; Okajima T.; Ishida M.; Maeda Y.; Murakami H.; Yamauchi M.; Hatsukade I.; Nobukawa M.; Nobukawa K. K.; Kohmura T.; Hagino K.; Kobayashi S.; Hiraga J. S.; Uchiyama H.; Yamaoka K.; Ozaki M.; Dotani T.; Tsunemi H.; the XRISM Xtend team  Meeting Abstracts of the Physical Society of Japan  74.2-  409  -409  2019
  • 村上弘志; 林田清; 冨田洋; 森浩二; 松本浩典; 野田博文; 常深博; 山内誠; 廿日出勇; 鶴剛; 田中孝明; 内田裕之; 幸村孝由; 萩野浩一; 小林翔悟; 中嶋大; 岡島崇; 石田学; 前田良知; 堂谷忠靖; 尾崎正伸; 内山秀樹; 山岡和貴; 信川正順; 信川久実子; 平賀純子  日本天文学会年会講演予稿集  2019-  2019
  • 岡崎貴樹; 林田清; 野田博文; 朝倉一統; 米山友景; 松本浩典; 信川久実子; 中嶋大; 金丸善朗; 佐藤仁; 西岡祐介; 森浩二; 冨田洋; 萩野浩一; 幸村孝由; 尾近洸行; 田中孝明; 内田裕之; 鶴剛; 村上弘志; 山内誠; 廿日出勇; 信川正順; 小林翔悟; 平賀純子; 内山秀樹; 山岡和貴; 尾崎正伸; 堂谷忠靖; 常深博  日本天文学会年会講演予稿集  2019-  2019
  • 齋藤真梨子; 信川久実子; 山内茂雄; 信川正順; 迫聖; 金丸善朗; 佐藤仁; 高木駿亨; 森浩二; 山内誠; 廿日出勇; 林田清; 野田博文; 松本浩典; 米山友景; 岡崎貴樹; 朝倉一統; 常深博; 冨田洋; 田中孝明; 内田裕之; 天野雄輝; 鶴剛; 中嶋大; 村上弘志; 内山秀樹; 幸村孝由; 萩野浩一; 小林翔悟; 山岡和貴; 平賀純子  日本天文学会年会講演予稿集  2019-  2019
  • 信川久実子; 岩垣純一; 岡崎貴樹; 米山友景; 野田博文; 林田清; 松本浩典; 中嶋大; 森浩二; 山内誠; 廿日出勇; 冨田洋; 田中孝明; 内田裕之; 鶴剛; 村上弘志; 萩野浩一; 幸村孝由; 信川正順; 小林翔悟; 平賀純子; 内山秀樹; 山岡和貴; 尾崎正伸; 堂谷忠靖; 常深博  日本天文学会年会講演予稿集  2019-  2019
  • 冨田洋; 林田清; 森浩二; 松本浩典; 野田博文; 常深博; 山内誠; 廿日出勇; 鶴剛; 田中孝明; 内田裕之; 幸村孝由; 萩野浩一; 小林翔悟; 中嶋大; 岡島崇; 石田学; 前田良知; 堂谷忠靖; 尾崎正伸; 村上弘志; 内山秀樹; 山岡和貴; 信川正順; 信川久実子; 平賀純子  日本天文学会年会講演予稿集  2019-  2019
  • 岩垣純一; 野田博文; 林田清; 岡崎貴樹; 朝倉一統; 米山友景; 松本浩典; 信川久実子; 中嶋大; 金丸善朗; 佐藤仁; 西岡祐介; 森浩二; 下井建生; 冨田洋; 萩野浩一; 幸村孝由; 尾近洸行; 田中孝明; 内田裕之; 鶴剛; 村上弘志; 山内誠; 廿日出勇; 信川正順; 小林翔悟; 平賀純子; 内山秀樹; 山岡和貴; 尾崎正伸; 堂谷忠靖; 常深博  日本天文学会年会講演予稿集  2019-  2019
  • 林田清; 岩垣純一; 米山友景; 岡崎貴樹; 朝倉一統; 松本浩典; 中嶋大; 金丸善朗; 佐藤仁; 西岡祐介; 森浩二; 山内誠; 廿日出勇; 内田裕之; 尾近洸行; 田中孝明; 鶴剛; 信川久実子; 平賀純子; 村上弘志; 冨田洋; 山岡和貴; 幸村孝由; 萩野浩一; 小林翔悟; 内山秀樹; 信川正順; 堂谷忠靖; 尾崎正伸; 常深博  日本天文学会年会講演予稿集  2018-  219  2018/08
  • 米山友景; 林田清; 岩垣純一; 岡崎貴樹; 朝倉一統; 松本浩典; 中嶋大; 金丸善朗; 佐藤仁; 西岡祐介; 森浩二; 山内誠; 廿日出勇; 内田裕之; 田中孝明; 尾近洸行; 鶴剛; 信川久実子; 平賀純子; 村上弘志; 冨田洋; 山岡和貴; 幸村孝由; 萩野浩一; 小林翔悟; 内山秀樹; 信川正順; 堂谷忠靖; 尾崎正伸; 常深博  日本天文学会年会講演予稿集  2018-  221  2018/08
  • 冨田洋; 石田学; 前田良知; 堂谷忠靖; 尾崎正伸; 林田清; 中嶋大; 松本浩典; 常深博; 森浩二; 山内誠; 廿日出勇; 鶴剛; 田中孝明; 内田裕之; 小林翔悟; 幸村孝由; 萩野浩一; 岡島崇; 村上弘志; 内山秀樹; 山岡和貴; 信川正順; 信川久実子; 平賀純子  日本天文学会年会講演予稿集  2018-  228  2018/02
  • 大西里実; 岩垣純一; 中嶋大; 林田清; 松本浩典; 常深博; 鶴剛; 田中孝明; 内田裕之; 小林翔悟; 冨田洋; 堂谷忠靖; 尾崎正伸; 森浩二; 山内誠; 廿日出勇; 幸村孝由; 萩野浩一; 村上弘志; 内山秀樹; 山岡和貴; 信川正順; 信川久実子; 平賀純子  日本天文学会年会講演予稿集  2018-  229  2018/02
  • Mori K.; Ishida M.; Maeda Y.; Murakami H.; Yamauchi M.; Hatsukade I.; Nobukawa M.; Nobukawa K. K.; Kohmura T.; Hagino K.; Kobayashi S.; Hayashida K.; Hiraga J. S.; Uchiyama H.; Yamaoka K.; Ozaki M.; Dotani T.; Tsunemi H.; the Xtend team; Tomida H.; Tanaka T.; Uchida H.; Tsuru T. G.; Nakajima H.; Matsumoto H.; Okajima T.  Meeting Abstracts of the Physical Society of Japan  73-  (0)  186  -186  2018
  • 長友竣; 長田哲也; 栗田光樹夫; 木野勝; 善光哲哉; 鶴剛; 山内茂雄; 信川久実子; 信川正順; 西山正吾  日本天文学会年会講演予稿集  2017-  161  2017/02
  • Katsuda Satoru; Yamaguchi Hiroya; Sawada Makoto; Nobukawa Kumiko; Hitomi collaboration  Meeting Abstracts of the Physical Society of Japan  72-  (0)  483  -483  2017
  • 信川 久実子  天文月報 = The astronomical herald  109-  (11)  773  -779  2016/11
  • 内田裕之; 田中孝明; 鶴剛; 常深博; 林田清; 中嶋大; 井上翔太; 森浩二; 坂田美穂; 西岡祐介; 山内誠; 廿日出勇; 堂谷忠靖; 尾崎正伸; 冨田洋; 夏苅権; 上田周太朗; 平賀純子; 信川正順; 村上弘志; 幸村孝由; 信川久実子  日本天文学会年会講演予稿集  2016-  243  2016/08
  • 井上翔太; 中嶋大; 林田清; 常深博; 村上弘志; 鶴剛; 田中孝明; 内田裕之; 森浩二; 坂田美穂; 西岡祐介; 山内誠; 廿日出勇; 堂谷忠靖; 尾崎正伸; 冨田洋; 夏苅権; 上田周太朗; 岩井將親; 平賀純子; 信川正順; 幸村孝由; 信川久実子  日本天文学会年会講演予稿集  2016-  244  2016/08
  • 坂田美穂; 安田賢杜; 別府達彦; 本田大悟; 森浩二; 山内誠; 廿日出勇; 西岡祐介; 平賀純子; 中嶋大; 井上翔太; 常深博; 林田清; 信川正順; 信川久実子; 鶴剛; 田中孝明; 内田裕之; 堂谷忠靖; 尾崎正伸; 冨田洋; 夏苅権; 上田周太朗; 岩井將親; 村上弘志; 幸村孝由  日本天文学会年会講演予稿集  2016-  244  2016/08
  • 安田賢杜; 坂田美穂; 別府達彦; 本田大悟; 森浩二; 山内誠; 廿日出勇; 西岡祐介; 常深博; 林田清; 中嶋大; 井上翔太; 鶴剛; 田中孝明; 内田裕之; 堂谷忠靖; 尾崎正伸; 冨田洋; 夏苅権; 上田周太朗; 岩井將親; 信川正順; 村上弘志; 平賀純子; 幸村孝由; 信川久実子  日本天文学会年会講演予稿集  2016-  243  2016/08
  • 松村英晃; 内田裕之; 田中孝明; 鶴剛; 伊藤真音; 信川正順; 信川久実子  日本天文学会年会講演予稿集  2016-  152  2016/08
  • 森浩二; 山内誠; 廿日出勇; 西岡祐介; 坂田美穂; 安田賢杜; 常深博; 林田清; 中嶋大; 井上翔太; 鶴剛; 田中孝明; 内田裕之; 堂谷忠靖; 尾崎正伸; 冨田洋; 夏苅権; 上田周太朗; 岩井將親; 信川正順; 村上弘志; 平賀純子; 幸村孝由; 信川久実子  日本天文学会年会講演予稿集  2016-  243  2016/08
  • 井上翔太; 林田清; 片多修平; 中嶋大; 薙野綾; 穴吹直久; 常深博; 鶴剛; 田中孝明; 内田裕之; 信川久実子; 鷲野遼作; 信川正順; 森浩二; 磯田依里; 坂田美穂; 幸村孝由; 丹野憧馬; 玉澤晃希; 吉野祐馬; 近野貴博; 上田周太朗  日本天文学会年会講演予稿集  2016-  204  2016/02
  • 信川久実子; 山内茂雄; 信川正順; 鶴剛; 小山勝二; 鳥居和史; 福井康雄  日本天文学会年会講演予稿集  2016-  116  2016/02
  • 内田裕之; 鷲野遼作; 信川久実子; 田中孝明; 鶴剛; 森浩二; 磯田依里; 坂田美穂; 西岡祐介; 山内誠; 廿日出勇; 常深博; 林田清; 中嶋大; 穴吹直久; 薙野綾; 堂谷忠靖; 尾崎正伸; 冨田洋; 夏苅権; 上田周太朗; 信川正順; 村上弘志; 幸村孝由; 平賀純子  日本天文学会年会講演予稿集  2016-  204  2016/02
  • 松村英晃; 鶴剛; 内田裕之; 田中孝明; 信川久実子; 鷲野遼作; 信川正順  日本天文学会年会講演予稿集  2016-  118  2016/02
  • 信川久実子; 信川正順; 鶴剛; 小山勝二; 山内茂雄  日本天文学会年会講演予稿集  2015-  167  2015/08
  • 内田裕之; 鷲野遼作; 小山勝二; 鶴剛; 田中孝明; 信川正順; 信川久実子; 高田明寛; 小池貴之  日本天文学会年会講演予稿集  2015-  171  2015/02
  • 信川久実子; 信川正順; 鶴剛; 内山秀樹; 小山勝二  日本天文学会年会講演予稿集  2014-  181  2014/08
  • 片多修平; 林田清; 中嶋大; 薙野綾; 穴吹直久; 常深博; 上田周太朗; 井上翔太; 信川正順; 内田裕之; 田中孝明; 鶴剛; 信川久実子; 森浩二; 武吉司; 幸村孝由  日本天文学会年会講演予稿集  2014-  278  2014/08
  • 信川久実子; 鶴剛; 田中孝明; 内田裕之; 信川正順; 常深博; 林田清; 穴吹直久; 中嶋大; 薙野綾; 堂谷忠靖; 尾崎正伸; 冨田洋; 夏苅権; 木村公; 山内誠; 森浩二; 廿日出勇; 西岡佑介; 幸村孝由; 平賀純子; 村上弘志  日本天文学会年会講演予稿集  2014-  274  2014/02
  • 信川久実子; 鶴剛; 田中孝明; 内田裕之; 信川正順; 常深博; 林田清; 穴吹直久; 中嶋大; 薙野綾; 堂谷忠靖; 尾崎正伸; 冨田洋; 夏苅権; 木村公; 山内誠; 森浩二; 廿日出勇; 西岡佑介; 幸村孝由; 平賀純子; 村上弘志  日本天文学会年会講演予稿集  2013-  289  2013/08
  • 信川久実子; 鶴剛; 田中孝明; 内田裕之; 信川正順; 大西隆雄; 中島真也; 菅原隆介; 八隅真人; 常深博; 林田清; 中嶋大; 穴吹直久; 薙野綾; 堂谷忠靖; 尾崎正伸; 夏苅権; 冨田洋; 廿日出勇; 山内誠; 森浩二; 幸村孝由; 村上弘志; 平賀純子  日本天文学会年会講演予稿集  2013-  275  2013/02

Awards & Honors

  • 2017/02 Inoue Foundation for Science FY2016 Inoue Research Award for Young Scientists
     
    受賞者: Kumiko K. Nobukawa
  • 2016/03 Kyoto University FY2015 Tachibana Honorable Mention Award
     
    受賞者: Kumiko K. Nobukawa

Research Grants & Projects

  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2023/04 -2027/03 
    Author : 信川 久実子; 武田 彩希; 勝田 哲; 中澤 知洋
  • 超小型衛星による X 線観測を用いた新手法で実現する低エネルギー銀河宇宙線の測定と起源解明
    公益財団法人 三菱財団：第54回（2023年度）三菱財団自然科学研究助成 若手助成
    Date (from‐to) : 2023/10 -2024/09 
    Author : 信川久実子
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2021/04 -2024/03 
    Author : 信川 正順; 内山 秀樹; 山内 茂雄; 信川 久実子
     
    本研究課題での目的は、これまで解明されていない銀河中心拡散X線放射(GCXE)の起源を次世代のX線天文衛星XRISMを用いて観測し、構成成分を定量的に分離し、その運動を初めて測定することである。 XRISMは2022年度打ち上げ予定であり、本研究課題の研究者全員は XRISMの開発メンバーの一員でもある。2021年度は XRISMの開発を進め、観測の準備を行った。特に、観測装置の開発ではフライトモデルの製作を行い、検証試験および性能確認試験を実施した。さらにデータ較正の方法の開発も進めるとともに、実データを用いて較正データベースの準備を行った。打ち上げ後の観測データ処理システムの開発を進め、テストデータを用いた確認を実施し、問題がないことを確認した。 さらに、すざく衛星によるデータを用いて、GCXEスペクトルを構成する成分の定量分析を行った。我々が2016年に調べた結果では、5keV以上のエネルギー帯域だけであったが、全エネルギー帯域のスペクトルを用いた。その結果、X線点源や冷たいX線成分だけでは観測スペクトルの再現はできないが、それらに真に広がったプラズマ成分を加えると再現できることがわかった。そのプラズマは温度kT~1 keVの過電離状態である可能性がある。特に、これまでは温度kT~7 keVと高温であるため、銀河の重力では留めておけないことが問題だった。それよりも低温であれば、その問題は解決できるかもしれない。 また、GCXEの高温プラズマの候補の1つである超新星残骸の研究も進めた。特に通常の超新星残骸プラズマの進化では考えられない過電離状態の起源を明らかにするために、通常の電離進行型の超新星残骸も含めた複数の天体データを集めて、系統調査を行った。その結果、過電離を示す天体の電子温度は、通常天体の電子温度の時間変化と矛盾がなく、電離が促進されている可能性がわかった。
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Fund for the Promotion of Joint International Research (Fostering Joint International Research (B))
    Date (from‐to) : 2020/10 -2024/03 
    Author : 中嶋 大; 野田 博文; 信川 久実子; 松本 浩典
     
    日独の共同研究により、将来の大有効面積X線望遠鏡の焦点面検出器として、高速低雑音X線撮像分光検出器を開発することが本研究の最終目的である。そのために、独マックスプランク地球外物理学研究所(MPE)の研究者が中心となりアクティブピクセルセンサDepFETを用いたフロントエンド部分を開発し、並行して我々がDepFET用電源回路および駆動回路を開発する。 2021年度は、特にDepFETの信号処理を行うフロントエンドASICに供給するアナログ電圧生成回路を開発した。1.7Vから2.2Vまでの範囲で精密に供給電圧を制御し、マイコンを用いたシリアル通信により計算機からコマンドを送信すると、それに応じて電圧を変化させることができる仕様である。また出力電圧は house keeping 情報としてモニタ可能としている。このブレッドボード回路を２枚制作し、初期動作試験を行っている。 上記と同時に、DepFET自体に与える印加電圧生成回路の設計を行っている。こちらは正負両側電圧を精密に制御するため、レギュレータを用いた回路を製作予定であり、部品選定までを完了した。 さらにDepFETと同じシリコン固体検出器に分類されるCMOSセンサを用いてこの回路の動作検証を行うため、CMOSセンサ冷却用ペルチェシステムを導入した。真空槽内での動作確認が完了し、従来のCMOS評価基板システムを用いた場合と遜色ない雑音レベルを得た。このシステムにはX線発生装置を接続し、二次ターゲットを差し替えることで様々な特性X線を照射しセンサの応答を評価できるようにしている。今後、このシステムを用いてセンサの応答関数構築試験を進める予定である。
  • 日本学術振興会：科学研究費助成事業 若手研究
    Date (from‐to) : 2020/04 -2024/03 
    Author : 信川 久実子
     
    超新星残骸 (SNR) は銀河宇宙線の起源と考えられている。銀河系内のSNR W51Cをすざく衛星で観測し、低エネルギー宇宙線が星間物質中の中性鉄原子を電離することで放射されたと考えられる中性鉄輝線を2.0σの有意度で検出した。またW51C近傍のHII領域G49.0-0.3からは3.4σの有意度でヘリウム状鉄輝線を検出した。G49.0-0.3からのX線放射は、温度~3.0 keVで元素組成比が~0.5太陽組成のプラズマであった。これはO型星からの星風で生成されたと考えられる。これらの結果を査読付き論文にまとめ受理された。並行して、銀河系中心の西側の領域に存在する超新星残骸で、低エネルギー宇宙線起源の中性鉄輝線の系統的な調査を行った。 電離率、中性鉄輝線、ガンマ線放射に寄与する宇宙線陽子のエネルギーはそれぞれ異なるため、3つの観測量を同じ場所で観測すれば、広帯域な宇宙線の情報が得られる。そこで中性鉄輝線とガンマ線が両方観測されている領域で電離率を測定するため、電波望遠鏡の観測提案を行い、採択された。
  • 公益財団法人 山田科学振興財団：2020年度研究援助
    Date (from‐to) : 2020/10 -2022/03
  • 鉄輝線精密分光による銀河宇宙線加速の初期機構解明
    日本学術振興会：特別研究員奨励費
    Date (from‐to) : 2016/04 -2020/03 
    Author : 信川 久実子
  • 高電離輝線の精密分光観測による銀河面Ｘ線放射の点源成分と拡散成分の定量的分離
    日本学術振興会：特別研究員奨励費
    Date (from‐to) : 2013/04 -2016/03 
    Author : 信川 久実子

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