2006/06/13 by C. O. Heinke, R. Wijnands, H. N. Cohn +4 · 3 citations
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Star Formation Studies #Cluster (spacecraft) #Galactic Center #Galaxy #Globular cluster #Luminosity #Metallicity #Physics #RADIUS #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/507884
published as Astrophys.J.651:1098-1111,2006 · 15 pages, 10 figures (3 color). Resubmitted to ApJ after incorporating referee comments. v2: Added references to introduction
arxiv created 2006/06/13 · openalex publication_date 2006/11/02 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We report our analysis of a Chandra X-ray observation of the rich globular cluster Terzan 5, in which we detect 50 sources to a limiting 1.0-6 keV X-ray luminosity of 3 × 10 31 ergs s -1 within the half-mass radius of the cluster. Thirty-three of these have L X > 10 32 ergs s -1 , 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.), 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 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 Jordán et al. for extragalactic LMXBs is consistent with our data.