A Chandra Catalog of X-ray Sources in the Central 150 pc of the Galaxy
(2006)cite arxiv:astro-ph/0601627
Comment: 16 pages, incl. 9 figures, 3 in color. Submitted to ApJ. An
electronic catalog of X-ray point sources is located at
http://astro.ucla.edu/~mmuno/sgra/shallow_survey_catalog.txt . A
high-resolution version of figure 1 will be available when the manuscript is
published.Abstract
We present the catalog of X-ray sources detected in a shallow Chandra survey
of the inner 2 by 0.8 degrees of the Galaxy, and in two deeper observations of
the Radio Arches and Sgr B2. The catalog contains 1352 objects that are
highly-absorbed (N_H > 4e22 cm^-2 and are therefore likely to lie near the
Galactic center (D~8 kpc), and 549 less-absorbed sources that lie within <6 kc
of Earth. Based on the inferred luminosities of the X-ray sources and the
expected numbers of various classes of objects, we suggest that the sources
with L_X < 1e33 erg/s that comprise ~90% of the catalog are cataclysmic
variables, and that the ~100 brighter objects are accreting neutron stars and
black holes, young isolated pulsars, and Wolf-Rayet and O stars in
colliding-wind binaries. We find that the spatial distribution of X-ray sources
matches that of the old stellar population observed in the infrared, which
supports our suggestion that most of the X-ray sources are old cataclysmic
variables. However, we find that there is an apparent excess of ~10 bright
sources in the Radio Arches region. That region is already known to be the site
of recent star formation, so we suggest that the bright sources in this region
are young high-mass X-ray binaries, pulsars, or WR/O star binaries. We briefly
discuss some astrophysical questions that this catalog can be used to address.
Description
A Chandra Catalog of X-ray Sources in the Central 150 pc of the Galaxy