X-Ray and Near-Infrared Spectroscopy of Dim X-Ray Point Sources Constituting the Galactic Ridge X-Ray Emission

Authors

  • Kumiko Morihana Nishiharima Astronomical Observatory, Center for Astronomy, University of Hyogo, 407-2 Nishigaichi, Sayo-cho, Sayo- gun, Hyogo, 679-5313, Japan
  • Masahiro Tsujimoto Japan Astrospace Exporation Agency, Institute of Space and Astronautical Science, 3-1-1 Yoshino-dai, Chuo-ku, Sagami- hara, Kanagawa 252-5210, Japan
  • Ken Ebisawa Japan Astrospace Exporation Agency, Institute of Space and Astronautical Science, 3-1-1 Yoshino-dai, Chuo-ku, Sagami- hara, Kanagawa 252-5210, Japan

DOI:

https://doi.org/10.14311/APP.2014.01.0222

Abstract

We present the results of X-ray and Near-Infrared observations of the Galactic Ridge X-ray Emission (GRXE). We extracted 2,002 X-ray point sources in the Chandra Bulge Field (l =0°.113, b = 1°.424) down to ~10-14.8 ergscm-2s-1 in 2-8 keV band with the longest observation (900 ks) of the GRXE. Based on X-ray brightness and hardness, we classied the X-ray point sources into three groups: A (hard), B (soft and broad spectrum), and C (soft and peaked spectrum). In order to know populations of the X-ray point sources, we carried out NIR imaging and spectroscopy observation. We identied 11% of X-ray point sources with NIR and extracted NIR spectra for some of them. Based on X-ray and NIR properties, we concluded that non-thermal sources in the group A are mostly active galactic nuclei and the thermal sources are mostly white dwarf binaries such as cataclysmic variables (CVs) and Pre-CVs. We concluded that the group B and C sources are X-ray active stars in flare and quiescence, respectively.

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Published

2014-12-04

Issue

Vol. 1 No. 1 (2014): FRASCATI WORKSHOP 2013

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Articles

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