Hitomi X-ray observation of the pulsar wind nebula G21.5-0.9

• Authors: AHARONIAN F.; AKAMATSU H.; AKIMOTO F.; ALLEN SW; ANGELINI L.; AUDARD M.; AWAKI H.; AXELSSON M.; BAMBA A.; BAUTZ MW; BLANDFORD R.; BRENNEMAN LW; BROWN GV; BULBUL E.; CACKETT EM; CHERNYAKOVA M.; CHIAO MP; COPPI PS; COSTANTINI E.; DE PLAA J.; DE VRIES CP; DEN HERDER JW; DONE C.; DOTANI T.; EBISAWA K.; ECKART ME; ENOTO T.; EZOE Y.; FABIAN AC; FERRIGNO C.; FOSTER AR; FUJIMOTO R.; FUKAZAWA Y.; FURUZAWA A.; GALEAZZI M.; GALLO LC; GANDHI P.; GIUSTINI M.; GOLDWURM A.; LY Gu; GUAINAZZI M.; HABA Y.; HAGINO K.; HAMAGUCHI K.; HARRUS IM; HATSUKADE I.; HAYASHI K.; HAYASHI T.; HAYASHIDA K.; HIRAGA JS; HORNSCHEMEIER A.; HOSHINO A.; HUGHES JP; ICHINOHE Y.; IIZUKA R.; INOUE H.; INOUE Y.; ISHIDA M.; ISHIKAWA K.; ISHISAKI Y.; IWAI M.; KAASTRA J.; KALLMAN T.; KAMAE T.; KATAOKA J.; KATSUDA S.; KAWAI N.; KELLEY RL; KILBOURNE CA; KITAGUCHI T.; KITAMOTO S.; KITAYAMA T.; KOHMURA T.; KOKUBUN M.; KOYAMA K.; KOYAMA S.; KRETSCHMAR P.; KRIMM HA; KUBOTA A.; KUNIEDA H.; LAURENT P.; LEE SH; LEUTENEGGER MA; LIMOUSIN O.; LOEWENSTEIN M.; LONG KS; LUMB D.; MADEJSKI G.; MAEDA Y.; MAIER D.; MAKISHIMA K.; MARKEVITCH M.; MATSUMOTO H.; MATSUSHITA K.; MCCAMMON D.; MCNAMARA BR; MEHDIPOUR M.; MILLER ED; MILLER JM; MINESHIGE S.; MITSUDA K.; MITSUISHI I.; MIYAZAWA T.; MIZUNO T.; MORI H.; MORI K.; MUKAI K.; MURAKAMI H.; MUSHOTZKY RF; NAKAGAWA T.; NAKAJIMA H.; NAKAMORI T.; NAKASHIMA S.; NAKAZAWA K.; NOBUKAWA KK; NOBUKAWA M.; NODA H.; ODAKA H.; OHASHI T.; OHNO M.; OKAJIMA T.; OTA N.; OZAKI M.; PAERELS F.; PALTANI S.; PETRE R.; PINTO C.; PORTER FS; POTTSCHMIDT K.; REYNOLDS CS; SAFI-HARB S.; SAITO S.; SAKAI K.; SASAKI T.; SATO G.; SATO K.; SATO R.; SAWADA M.; SCHARTEL N.; SERLEMTSOS PJ; SETA H.; SHIDATSU M.; SIMIONESCU A.; SMITH RK; SOONG Y.; STAWARZ L.; SUGAWARA Y.; SUGITA S.; SZYMKOWIAK A.; TAJIMA H.; TAKAHASHI H.; TAKAHASHI T.; TAKEDA S.; TAKEI Y.; TAMAGAWA T.; TAMURA T.; TANAKA T.; TANAKA Y.; TANAKA YT; TASHIRO MS; TAWARA Y.; TERADA Y.; TERASHIMA Y.; TOMBESI F.; TOMIDA H.; TSUBOI Y.; TSUJIMOTO M.; TSUNEMI H.; TSURU TG; UCHIDA H.; UCHIYAMA H.; UCHIYAMA Y.; UEDA S.; UNO S.; UEDA Y.; URRY CM; URSINO E.; WATANABE S.; WERNER Norbert; WILKINS DR; WILLIAMS BJ; YAMADA S.; YAMAGUCHI H.; YAMAOKA K.; YAMASAKI NY; YAMAUCHI M.; YAMAUCHI S.; YAQOOB T.; YATSU Y.; YONETOKU D.; ZHURAVLEVA I.; ZOGHBI A.; SATO T.; NAKANIWA N.; MURAKAMI H.; GUEST B.
• Year of publication: 2018
• Type: Article in Periodical
• Magazine / Source: PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN
• MU Faculty or unit: Faculty of Science

Web

• https://academic.oup.com/pasj/article/70/3/38/4961358
• https://arxiv.org/pdf/1802.05068.pdf

• Doi: http://dx.doi.org/10.1093/pasj/psy027
• Keywords: ISM: individual objects (G21.5-0.9); ISM: supernova remnants; pulsars: individual (PSR J1833-1034)
• 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, 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 Gamma(1) = 1.74 +/- 0.02 and Gamma(2) = 2.14 +/- 0.01 below and above the break at 7.1 +/- 0.3 keV, which is significantly lower than the NuSTAR result (similar to 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 sigma. 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.