X-RAY POINT-SOURCE POPULATIONS CONSTITUTING THE GALACTIC RIDGE X-RAY EMISSION

• Published in: The Astrophysical journal Vol. 766; no. 1; pp. 14 - 13
• Main Authors: Morihana, Kumiko, Tsujimoto, Masahiro, Yoshida, Tessei, Ebisawa, Ken
• Format: Journal Article
• Language: English
• Published: United States 20.03.2013
• Subjects: ASTRONOMY; ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COLOR; Color-color diagram; Constraining; EMISSION; Emission spectroscopy; GALAXIES; GALAXY NUCLEI; KEV RANGE; Photometry; POINT SOURCES; Ridges; SPECTRA; SYMBIOTIC STARS; WHITE DWARF STARS; X RADIATION; X-rays
• ISSN: 0004-637X; 1538-4357
• DOI: 10.1088/0004-637X/766/1/14

Apparently diffuse X-ray emission has been known to exist along the central quarter of the Galactic Plane since the beginning of X-ray astronomy; this is referred to as the Galactic Ridge X-ray emission (GRXE). Recent deep X-ray observations have shown that numerous X-ray point sources account for a large fraction of the GRXE in the hard band (2-8 keV). Using the deepest X-ray observations made in the Chandra bulge field, we present the result of a coherent photometric and spectroscopic analysis of individual X-ray point sources for the purpose of constraining their nature and deriving their fractional contributions to the hard-band continuum and Fe K line emission of the GRXE. Based on the X-ray color-color diagram, we divided the point sources into three groups: A (hard), B (soft and broad spectrum), and C (soft and peaked spectrum). The Fe K alpha emission is mostly from the group A thermal (WD binaries) and the group B (X-ray active stars) sources.