Astronomy and Astrophysics – Astrophysics
Scientific paper
2004-05-10
Astrophys.J. 613 (2004) 279-301
Astronomy and Astrophysics
Astrophysics
23 pages, 21 figures. Accepted for publication in ApJ. Also available at http://www.physics.rutgers.edu/~pcote/acs/publication
Scientific paper
10.1086/422545
The ACIS instrument on board the Chandra X-ray Observatory has been used to carry out the first systematic study of low-mass X-ray binaries (LMXBs) in M87. We identify 174 X-ray point-sources, of which ~150 are likely LMXBs. This LMXB catalog is combined with deep F475W and F850LP images taken with ACS on HST to examine the connection between LMXBs and globular clusters in M87. Of the 1688 globular clusters in our catalog, f_X = 3.6 +- 0.5% contain a LMXB and we find that the metal-rich clusters are 3 +- 1 times more likely to harbor a LMXB than their metal-poor counterparts. In agreement with previous findings for other galaxies, we find that brighter, more metal-rich clusters are more likely to contain a LMXB. For the first time, however, we are able to demonstrate that the probability, p_X, that a given cluster will contain a LMXB depends sensitively on the dynamical properties of the host cluster. Specifically, we use the HST images to measure the half-light radius, concentration index and central density, \rho_0, for each globular, and define a parameter, \Gamma, which is related to the tidal capture and binary-neutron star exchange rate. Our preferred form for p_X is then p_X \propto \Gamma \rho_0^{-0.42\pm0.11} (Z/Z_{\odot})^{0.33\pm0.1}. We argue that if the form of p_X is determined by dynamical processes, then the observed metallicity dependence is a consequence of an increased number of neutron stars per unit mass in metal-rich globular clusters. Finally, we find no compelling evidence for a break in the luminosity distribution of resolved X-ray point sources. Instead, the LMXB luminosity function is well described by a power law with an upper cutoff at L_X ~ 10^39 erg/s. (abridged)
Blakeslee John P.
Cote' Patrick
Ferrarese Laura
Jord'an Andrés
Mei Simona
No associations
LandOfFree
The ACS Virgo Cluster Survey III. Chandra and HST Observations of Low-Mass X-Ray Binaries and Globular Clusters in M87 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The ACS Virgo Cluster Survey III. Chandra and HST Observations of Low-Mass X-Ray Binaries and Globular Clusters in M87, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The ACS Virgo Cluster Survey III. Chandra and HST Observations of Low-Mass X-Ray Binaries and Globular Clusters in M87 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-672242