| |
 |
| Paper: |
The Chandra Galactic Bulge Survey |
| Volume: |
491, Fifty Years of Wide Field Studies in the Southern Hemisphere: Resolved Stellar Populations in the Galactic Bulge and the Magellanic Clouds |
| Page: |
77 |
| Authors: |
Britt, C. T.; Hynes, R. I.; Jonker, P. G.; Maccarone, T.; Torres, M. A. P.; Steeghs, D.; Nelemans, G.; Johnson, C.; Greiss, S. |
| Abstract: |
The Chandra Galactic Bulge Survey (GBS) is a multi-wavelength survey
of two 6×1 degree strips
above and below the Galactic plane, including deep r' and i'
imaging and time domain photometry from CTIO and shallow, wide-field
X-ray imaging with Chandra. Targeting fields above |b|=1 avoids most
of the copious extinction along the Galactic plane while maintaining
high source density. This results in targets that are accessible to
follow up in optical and NIR wavelengths. The X-ray observations are
shallow to maximize the number of quiescent Low Mass X-ray Binaries
(LMXBs) relative to Cataclysmic Variables (CVs). The goals of the GBS
are to conduct a census of Low Mass X-ray Binaries in the Milky Way in
order to constrain models of binary evolution, the common envelope
phase in particular, and to expand the number of known LMXBs for
optical follow up. Mass measurements in particular will help constrain
the black hole (BH) mass distribution and the equation of state for
neutron stars (NS). Constraining the BH mass distribution will
constrain models of their formation in supernovae. The current
population of Galactic BHs suffers from selection effects, which the
GBS avoids by finding new objects while still in quiescence. We expect
to find qLMXBs, magnetic CVs, RS CVn stars, and smaller numbers of
other types of sources. After removing duplicates, there are 1640
unique X-ray sources in the 12 square degree survey area, which
closely matches the predicted number of 1648. We are currently
matching X-ray sources to counterparts in other wavelengths using new
photometric and spectroscopic observations as well as in archival data
where it exists, and searching for variability and periodicity in the
counterparts in photometric data. So far, we have spectroscopically
identified 27 interacting binaries including promising candidates for
quiescent black holes. |
|
|
|
|
|
