@article{a7ae3b94c91d412f9b724ee41121ffe5,
title = "Hitomi X-ray observation of the pulsar wind nebula G21.5-0.9",
abstract = "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.",
keywords = "ISM: individual objects(G21.5-0.9), ISM: supernovaremnants, pulsars: individual(PSR J1833-1034)",
author = "{Hitomi Collaboration} and Felix Aharonian and Hiroki Akamatsu and Fumie Akimoto and Allen, {Steven W.} and Lorella Angelini and Marc Audard and Hisamitsu Awaki and Magnus Axelsson and Aya Bamba and Bautz, {Marshall W.} and Roger Blandford and Brenneman, {Laura W.} and Brown, {Gregory V.} and Esra Bulbul and Cackett, {Edward M.} and Maria Chernyakova and Chiao, {Meng P.} and Coppi, {Paolo S.} and Elisa Costantini and {De Plaa}, Jelle and {De Vries}, {Cor P.} and {Den Herder}, {Jan Willem} and Chris Done and Tadayasu Dotani and Ken Ebisawa and Eckart, {Megan E.} and Teruaki Enoto and Yuichiro Ezoe and Fabian, {Andrew C.} and Carlo Ferrigno and Foster, {Adam R.} and Ryuichi Fujimoto and Yasushi Fukazawa and Akihiro Furuzawa and Massimiliano Galeazzi and Gallo, {Luigi C.} and Poshak Gandhi and Margherita Giustini and Andrea Goldwurm and Liyi Gu and Matteo Guainazzi and Yoshito Haba and Kouichi Hagino and Kenji Hamaguchi and Harrus, {Ilana M.} and Isamu Hatsukade and Katsuhiro Hayashi and Takayuki Hayashi and Kiyoshi Hayashida and Hiraga, {Junko S.}",
note = "Funding Information: We thank D. A. Smith and M. Kerr for giving us the detailed information on the Fermi LAT observations of PSR J1833−1034. We acknowledge the support from the JSPS Core-to-Core Program, and all the JAXA members who have contributed to the ASTRO-H (Hitomi) project. All U.S. members gratefully acknowledge support through the NASA Science Mission Directorate. Stanford and SLAC members acknowledge support via the DoE contract to the SLAC National Accelerator Laboratory DE-AC3-76SF00515. Part of this work was performed under the auspices of the U.S DoE by LLNL under Contract DE-AC52-07NA27344. Support from the European Space Agency is gratefully acknowledged. French members acknowledge support from CNES, the Centre National d{\textquoteright}{\'E}tudes Spatiales. SRON is supported by NWO, the Netherlands Organization for Scientific Research. The Swiss team acknowledges the support of the Swiss Secretariat for Education, Research and Innovation (SERI). The Canadian Space Agency is acknowledged for the support of the Canadian members. We acknowledge support from JSPS/MEXT KAKENHI grant numbers JP15H00773, JP15H00785, JP15H02070, JP15H02090, JP15H03639, JP15H03641, JP15H03642, JP15H05438, JP15H06896, JP15K05107, JP15K17610, JP15K17657, JP16H00949, JP16H03983, JP16H06342, JP16J02333, JP16K05295, JP16K05296, JP16K05300, JP16K05309, JP16K13787, JP16K17667, JP16K17672, JP16K17673, JP17H02864, JP17K05393, JP21659292, JP23340055, JP23340071, JP23540280, JP24105007, JP24540232, JP25105516, JP25109004, JP25247028, JP25287042, JP25400236, JP25800119, JP26109506, JP26220703, JP26400228, JP26610047, and JP26800102. The following NASA grants are acknowledged: NNX15AC76G, NNX15AE16G, NNX15AK71G, NNX15AU54G, NNX15AW94G, and NNG15PP48P to Eureka Scientific. This work was partly supported by Leading Initiative for Excellent Young Researchers, MEXT, Japan, and also by the Research Fellowship of JSPS for Young Scientists. H. Akamatsu acknowledges the support of NWO via a Veni grant. C. Done acknowledges STFC funding under grant ST/L00075X/1. A. Fabian and C. Pinto acknowledge ERC Advanced Grant 340442. P. Gandhi acknowledges JAXA International Top Young Fellowship and UK Science and Technology Funding Council (STFC) grant ST/J003697/2. Y. Ichinohe and K. Nobukawa are supported by the Research Fellow of JSPS for Young Scientists. N. Kawai is supported by the Grant-in-Aid for Scientific Research on Innovative Areas “New Developments in Astrophysics Through Multi-Messenger Observations of Gravitational Wave Sources.” S. Kitamoto is partially supported by the MEXT Supported Program for the Strategic Research Foundation at Private Universities, 2014–2018. B. McNamara and S. Safi-Harb acknowledge support from NSERC. T. Dotani, T. Takahashi, T. Tamagawa, M. Tsujimoto, and Y. Uchiyama acknowledge support from the Grant-in-Aid for Scientific Research on Innovative Areas “Nuclear Matter in Neutron Stars Investigated by Experiments and Astronomical Observations.” N. Werner is supported by the Lend{\"u}let LP2016-11 grant from the Hungarian Academy of Sciences. D. Wilkins is supported by NASA through Einstein Fellowship grant number PF6-170160, awarded by the Chandra X-ray Center, operated by the Smithsonian Astrophysical Observatory for NASA under contract NAS8-03060. We are grateful for contributions by many companies, including in particular, NEC, Mitsubishi Heavy Industries, Sumitomo Heavy Industries, and Japan Aviation Electronics Industry. Publisher Copyright: {\textcopyright} 2018 The Author(s).",
year = "2018",
month = jun,
day = "1",
doi = "10.1093/pasj/psy027",
language = "English (US)",
volume = "70",
journal = "Publication of the Astronomical Society of Japan",
issn = "0004-6264",
publisher = "Astronomical Society of Japan",
number = "3",
}