Faint X‐Ray Sources in the Globular Cluster Terzan 5

We report our analysis of a Chandra X-ray observation of the rich globularcluster Terzan 5, in which we detect 50 sources to a limiting 1.0-6 keV X-rayluminosity of 3*10^{31} ergs/s within the half-mass radius of the cluster.Thirty-three of these have L_X>10^{32} ergs/s, the largest number yet seen inany globular cluster. In addition to the quiescent low-mass X-ray binary (LMXB,identified by Wijnands et al.), another 12 relatively soft sources may bequiescent LMXBs. We compare the X-ray colors of the harder sources in Terzan 5to the Galactic Center sources studied by Muno and collaborators, and find theGalactic Center sources to have harder X-ray colors, indicating a possibledifference in the populations. We cannot clearly identify a metallicitydependence in the production of low-luminosity X-ray binaries in Galacticglobular clusters, but a metallicity dependence of the form suggested by Jordanet al. for extragalactic LMXBs is consistent with our data.Comment: 15 pages, 10 figures (3 color). Resubmitted to ApJ after incorporating referee comments. v2: Added references to introductio