論文

2015年12月

Number density distribution of near-infrared sources on a sub-degree scale in the Galactic center: Comparison with the Fe XXV K alpha line at 6.7 keV

PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN
  • Kazuki Yasui
  • Shogo Nishiyama
  • Tatsuhito Yoshikawa
  • Schun Nagatomo
  • Hideki Uchiyama
  • Takeshi Go Tsuru
  • Katsuji Koyama
  • Motohide Tamura
  • Jungmi Kwon
  • Koji Sugitani
  • Rainer Schodel
  • Tetsuya Nagata
  • 全て表示

67
6
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1093/pasj/psv100
出版者・発行元
OXFORD UNIV PRESS

The stellar distribution derived from an H- and KS-band survey of the central region of our Galaxy is compared with the Fe xxv K alpha (6.7 keV) line intensity observed with the Suzaku satellite. The survey is for the galactic coordinates |l| less than or similar to 3 degrees 0 and |b| less than or similar to 1 degrees 0 (equivalent to 0.8 kpc x 0.3 kpc for R-circle dot = 8 kpc), and the number-density distribution N( K-S,(0); l, b) of stars is derived by using the extinction-corrected magnitude K-S,(0) = 10.5. This is deep enough to probe the old red-giant population and in turn to estimate the (l, b) distribution of faint X-ray point sources such as coronally active binaries and cataclysmic variables. In the Galactic plane (b= 0 degrees.), N(10.5; l, b) increases in the direction of the Galactic center as | l |(- 0.30 +/- 0.03) in the range of - 0 degrees.1 greater than or similar to l greater than or similar to - 0 degrees.7, but this increase is significantly slower than the increase (| l|(- 0.44 +/- 0.02)) of the Fe xxv K alpha line intensity. If normalized with the ratios in the outer region 1 degrees.5 less than or similar to | l | less than or similar to 2.degrees. 8, where faint X-ray point sources are argued to dominate the diffuse Galactic X-ray ridge emission, the excess of the Fe xxv K alpha line intensity over the stellar number density is at least a factor of two at | l | = 0.degrees 1. This indicates that a significant part of the Galactic-center diffuse emission arises from a truly diffuse optically thin thermal plasma, and not from an unresolved collection of faint X-ray point sources related to the old stellar population.

リンク情報
DOI
https://doi.org/10.1093/pasj/psv100
arXiv
http://arxiv.org/abs/arXiv:1510.06832
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000389248100001&DestApp=WOS_CPL
URL
http://arxiv.org/abs/1510.06832v2
ID情報
  • DOI : 10.1093/pasj/psv100
  • ISSN : 0004-6264
  • eISSN : 2053-051X
  • arXiv ID : arXiv:1510.06832
  • Web of Science ID : WOS:000389248100001

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