Globular Cluster X-ray Sources.

I report the preliminary results of two recent Chandra surveys which together resulted in new observations of 30 Galactic globular clusters. The aim of these observations is to probe in detail the overabundance of various classes of X-ray sources—low-mass X-ray binaries (LMXBs), cataclysmic variables (CVs), millisecond pulsars (MSPs), and active main-sequence binaries (ABs)—in globular clusters. The overabundance of low-mass X-ray binaries in outburst has long been known and is the result of the dynamical interactions unique to the dense stellar environs in globular clusters. Results from the early Chandra observations of globular clusters established that the entire low-mass X-ray binary population (including the low-luminosity quiescent systems) is overabundant, as is the cataclysmic variable population. When combined with previous Chandra observations, these two recent surveys have uncovered over 90% of the dynamically formed X-ray source population in all Galactic globular clusters. These sources are a powerful probe of the internal dynamics of globular clusters. In addition, these data test the recent suggestion (Fregeau 2008) that we have misunderstood the dynamical states of globular clusters. [ABSTRACT FROM AUTHOR]