Hitomi X-ray Observation of the Pulsar Wind Nebula G21.5$-$0.9
Creators: name: Hitomi Collaboration
name: Aharonian, Felix
name: Akamatsu, Hiroki
name: Akimoto, Fumie
name: Allen, Steven W.
name: Angelini, Lorella
name: Audard, Marc
name: Awaki, Hisamitsu
name: Axelsson, Magnus
name: Bamba, Aya
name: Bautz, Marshall W.
name: Blandford, Roger
name: Brenneman, Laura W.
name: Brown, Gregory V.
name: Bulbul, Esra
name: Cackett, Edward M.
name: Chernyakova, Maria
name: Chiao, Meng P.
name: Coppi, Paolo S.
name: Costantini, Elisa
name: de Plaa, Jelle
name: de Vries, Cor P.
name: Herder, Jan-Willem den
name: Done, Chris
name: Dotani, Tadayasu
name: Ebisawa, Ken
name: Eckart, Megan E.
name: Enoto, Teruaki
name: Ezoe, Yuichiro
name: Fabian, Andrew C.
name: Ferrigno, Carlo
name: Foster, Adam R.
name: Fujimoto, Ryuichi
name: Fukazawa, Yasushi
name: Furuzawa, Akihiro
name: Galeazzi, Massimiliano
name: Gallo, Luigi C.
name: Gandhi, Poshak
name: Giustini, Margherita
name: Goldwurm, Andrea
name: Gu, Liyi
name: Guainazzi, Matteo
name: Haba, Yoshito
name: Hagino, Kouichi
name: Hamaguchi, Kenji
name: Harrus, Ilana M.
name: Hatsukade, Isamu
name: Hayashi, Katsuhiro
name: Hayashi, Takayuki
name: Hayashida, Kiyoshi
name: Hiraga, Junko S.
name: Hornschemeier, Ann
name: Hoshino, Akio
name: Hughes, John P.
name: Ichinohe, Yuto
name: Iizuka, Ryo
name: Inoue, Hajime
name: Inoue, Yoshiyuki
name: Ishida, Manabu
name: Ishikawa, Kumi
name: Ishisaki, Yoshitaka
name: Iwai, Masachika
name: Kaastra, Jelle
name: Kallman, Tim
name: Kamae, Tsuneyoshi
name: Kataoka, Jun
name: Katsuda, Satoru
name: Kawai, Nobuyuki
name: Kelley, Richard L.
name: Kilbourne, Caroline A.
name: Kitaguchi, Takao
name: Kitamoto, Shunji
name: Kitayama, Tetsu
name: Kohmura, Takayoshi
name: Kokubun, Motohide
name: Koyama, Katsuji
name: Koyama, Shu
name: Kretschmar, Peter
name: Krimm, Hans A.
name: Kubota, Aya
name: Kunieda, Hideyo
name: Laurent, Philippe
name: Lee, Shiu-Hang
name: Leutenegger, Maurice A.
name: Limousin, Olivier
name: Loewenstein, Michael
name: Long, Knox S.
name: Lumb, David
name: Madejski, Greg
name: Maeda, Yoshitomo
name: Maier, Daniel
name: Makishima, Kazuo
name: Markevitch, Maxim
name: Matsumoto, Hironori
name: Matsushita, Kyoko
name: McCammon, Dan
name: McNamara, Brian R.
name: Mehdipour, Missagh
name: Miller, Eric D.
name: Miller, Jon M.
name: Mineshige, Shin
name: Mitsuda, Kazuhisa
name: Mitsuishi, Ikuyuki
name: Miyazawa, Takuya
name: Mizuno, Tsunefumi
name: Mori, Hideyuki
name: Mori, Koji
name: Mukai, Koji
name: Murakami, Hiroshi
name: Mushotzky, Richard F.
name: Nakagawa, Takao
name: Nakajima, Hiroshi
name: Nakamori, Takeshi
name: Nakashima, Shinya
name: Nakazawa, Kazuhiro
name: Nobukawa, Kumiko K.
name: Nobukawa, Masayoshi
name: Noda, Hirofumi
name: Odaka, Hirokazu
name: Ohashi, Takaya
name: Ohno, Masanori
name: Okajima, Takashi
name: Ota, Naomi
name: Ozaki, Masanobu
name: Paerels, Frits
name: Paltani, Stéphane
name: Petre, Robert
name: Pinto, Ciro
name: Porter, Frederick S.
name: Pottschmidt, Katja
name: Reynolds, Christopher S.
name: Safi-Harb, Samar
name: Saito, Shinya
name: Sakai, Kazuhiro
name: Sasaki, Toru
name: Sato, Goro
name: Sato, Kosuke
name: Sato, Rie
name: Sato, Toshiki
name: Sawada, Makoto
name: Schartel, Norbert
name: Serlemtsos, Peter J.
name: Seta, Hiromi
name: Shidatsu, Megumi
name: Simionescu, Aurora
name: Smith, Randall K.
name: Soong, Yang
name: Stawarz, Łukasz
name: Sugawara, Yasuharu
name: Sugita, Satoshi
name: Szymkowiak, Andrew
name: Tajima, Hiroyasu
name: Takahashi, Hiromitsu
name: Takahashi, Tadayuki
name: Takeda, Shin'ichiro
name: Takei, Yoh
name: Tamagawa, Toru
name: Tamura, Takayuki
name: Tanaka, Takaaki
name: Tanaka, Yasuo
name: Tanaka, Yasuyuki T.
name: Tashiro, Makoto S.
name: Tawara, Yuzuru
name: Terada, Yukikatsu
name: Terashima, Yuichi
name: Tombesi, Francesco
name: Tomida, Hiroshi
name: Tsuboi, Yohko
name: Tsujimoto, Masahiro
name: Tsunemi, Hiroshi
name: Tsuru, Takeshi Go
name: Uchida, Hiroyuki
name: Uchiyama, Hideki
name: Uchiyama, Yasunobu
name: Ueda, Shutaro
name: Ueda, Yoshihiro
name: Uno, Shin'ichiro
name: Urry, C. Megan
name: Ursino, Eugenio
name: Watanabe, Shin
name: Werner, Norbert
name: Wilkins, Dan R.
name: Williams, Brian J.
name: Yamada, Shinya
name: Yamaguchi, Hiroya
name: Yamaoka, Kazutaka
name: Yamasaki, Noriko Y.
name: Yamauchi, Makoto
name: Yamauchi, Shigeo
name: Yaqoob, Tahir
name: Yatsu, Yoichi
name: Yonetoku, Daisuke
name: Zhuravleva, Irina
name: Zoghbi, Abderahmen
name: Sato, Toshiki
name: Nakaniwa, Nozomu
name: Murakami, Hiroaki
name: Guest, Benson
Publisher: name: arXiv
Year: 2018
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: 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 (SXI) 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 $Γ_1=1.74\pm0.02$ and $Γ_2=2.14\pm0.01$ below and above the break at $7.1\pm0.3$ keV, which is significantly lower than the NuSTAR result ($\sim9.0$ 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 SGD. 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 $σ$. 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.
description: 16 pages, 8 figures, 4 tables. Accepted for publication in PASJ