TY - JOUR
T1 - The MAVERIC survey
T2 - Chandra/ACIS catalog of faint X-ray sources in 38 galactic globular clusters
AU - Bahramian, Arash
AU - Strader, Jay
AU - Miller-Jones, James C.A.
AU - Chomiuk, Laura
AU - Heinke, Craig O.
AU - Maccarone, Thomas J.
AU - Pooley, David
AU - Shishkovsky, Laura
AU - Tudor, Vlad
AU - Zhao, Yue
AU - Li, Kwan Lok
AU - Sivakoff, Gregory R.
AU - Tremou, Evangelia
AU - Buchner, Johannes
N1 - Funding Information:
We thank the anonymous referee for their helpful comments. A.B. thanks Patrick Broos, Diogo Belloni, Liliana Rivera Sandoval, and Scott Ransom for helpful discussions. J.C.A.M.J. is the recipient of an Australian Research Council Future Fellowship (FT140101082) funded by the Australian government. L.C. is grateful for the support of NASA grants Chandra-G06-17040X, Chandra-GO7-18032A, and HST-GO-14351. J.S. acknowledges support from a Packard Fellowship, NASA grants Chandra-GO3-14029X, Chandra-GO5-16036X, and Chandra-GO8-19122X, and NSF grants AST-1308124 and AST-1514763. C.O.H. and G.R.S. acknowledge NSERC Discovery Grants RGPIN-2016-04602 and RGPIN-2016-06569, respectively, and C.O.H. also a Discovery Accelerator Supplement. K.L.L. is supported by the Ministry of Science and Technology of the Republic of China (Taiwan) through grant 108-2112-M-007-025-MY3. We acknowledge extensive use of NASA's Astrophysics Data System Bibliographic Services, Arxiv, and SIMBAD (Wenger et al. 2000).
Publisher Copyright:
© 2020. The Author(s). Published by the American Astronomical Society.
PY - 2020/9/20
Y1 - 2020/9/20
N2 - Globular clusters host a variety of lower-luminosity (LX < 1035 erg s−1) X-ray sources, including accreting neutron stars (NSs) and black holes (BHs), millisecond pulsars (MSPs), cataclysmic variables, and chromospherically active binaries. In this paper, we provide a comprehensive catalog of more than 1100 X-ray sources in 38 Galactic globular clusters (GCs) observed by the Chandra X-ray Observatory's Chandra/ACIS detector. The targets are selected to complement the MAVERIC survey's deep radio continuum maps of Galactic GCs. We perform photometry and spectral analysis for each source, determine a best-fit model, and assess the possibility of it being a foreground or background source based on its spectral properties and location in the cluster. We also provide basic assessments of variability. We discuss the distribution of X-ray binaries in GCs and their X-ray luminosity function, and we carefully analyze systems with LX > 1033 erg s−1. Among these moderately bright systems, we discover a new source in NGC 6539 that may be a candidate accreting stellar-mass BH or a transitional MSP. We show that quiescent NS low-mass X-ray binaries in GCs may spend ∼2% of their lifetimes as transitional MSPs in their active (LX > 1033 erg s−1) state. Finally, we identify a substantial underabundance of bright (LX > 1033 erg s−1) intermediate polars in GCs compared to the Galactic field, in contrast with the literature of the past two decades.
AB - Globular clusters host a variety of lower-luminosity (LX < 1035 erg s−1) X-ray sources, including accreting neutron stars (NSs) and black holes (BHs), millisecond pulsars (MSPs), cataclysmic variables, and chromospherically active binaries. In this paper, we provide a comprehensive catalog of more than 1100 X-ray sources in 38 Galactic globular clusters (GCs) observed by the Chandra X-ray Observatory's Chandra/ACIS detector. The targets are selected to complement the MAVERIC survey's deep radio continuum maps of Galactic GCs. We perform photometry and spectral analysis for each source, determine a best-fit model, and assess the possibility of it being a foreground or background source based on its spectral properties and location in the cluster. We also provide basic assessments of variability. We discuss the distribution of X-ray binaries in GCs and their X-ray luminosity function, and we carefully analyze systems with LX > 1033 erg s−1. Among these moderately bright systems, we discover a new source in NGC 6539 that may be a candidate accreting stellar-mass BH or a transitional MSP. We show that quiescent NS low-mass X-ray binaries in GCs may spend ∼2% of their lifetimes as transitional MSPs in their active (LX > 1033 erg s−1) state. Finally, we identify a substantial underabundance of bright (LX > 1033 erg s−1) intermediate polars in GCs compared to the Galactic field, in contrast with the literature of the past two decades.
KW - Astrophysical black holes (98)
KW - Celestial objects catalogs (212)
KW - Globular star clusters (656)
KW - Low-mass x-ray binary stars (939)
KW - Neutron stars (1108)
KW - Stellar accretion disks (1579)
UR - http://www.scopus.com/inward/record.url?scp=85092631442&partnerID=8YFLogxK
U2 - 10.3847/1538-4357/aba51d
DO - 10.3847/1538-4357/aba51d
M3 - Review article
AN - SCOPUS:85092631442
SN - 0004-637X
VL - 901
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 57
ER -