Faint X-ray sources in Terzan 5

Thirty-three of these have LX>10^32^ergs/s, the largest number yet seen in any globular cluster. In addition to the quiescent low-mass X-ray binary (LMXB; identified by Wijnands et al., 2005ApJ...618..883W), another 12 relatively soft sources may be quiescent LMXBs.

We compare the X-ray colors of the harder sources in Terzan 5 to the Galactic center sources studied by Muno and collaborators (2003, Cat. <J/ApJ/589/225>) and find the Galactic center sources to have harder X-ray colors, indicating a possible difference in the populations. We cannot clearly identify a metallicity dependence in the production of low-luminosity X-ray binaries in Galactic globular clusters, but a metallicity dependence of the form suggested by Jordan et al. (2004, Cat. <J/ApJ/613/270>) for extragalactic LMXBs is consistent with our data.