A deeper look at the X-ray point source population of NGC 4472

Abstract

In this paper we discuss the X-ray point source population of NGC 4472, an elliptical galaxy in the Virgo cluster. We used recent deep Chandra data combined with archival Chandra data to obtain a 380 ks exposure time. We find 238 X-ray point sources within 3.7' of the galaxy centre, with a completeness flux, F(X,0.5-2 keV)= 6.3x$10^{-16}$ $erg{s}^{-1}c{m}^{-2}$. Most of these sources are expected to be low mass X-ray binaries. We finding that, using data from a single galaxy which is both complete and has a large number of objects (~ 100) below 10${}^{38}$ $erg{s}^{-1}$, the X-ray luminosity function is well fit with a single power law model. By cross matching our X-ray data with both space based and ground based optical data for NGC 4472, we find that 80 of the 238 sources are in globular clusters. We compare the red and blue globular cluster subpopulations and find red clusters are nearly six times more likely to host an X-ray source than blue clusters. We show that there is evidence that these two subpopulations have significantly different X-ray luminosity distributions. Source catalogues for all X-ray point sources, as well as any corresponding optical data for globular cluster sources, are also presented here.

14 pages, 4 figures, 2 data tables

References in corpus (6)

• Comparing GC and Field LMXBs in Elliptical Galaxies with deep Chandra and Hubble data
• Luminosity functions of LMXBs in Centaurus A: globular clusters versus the field
• The X-ray Luminosity Functions of Field Low Mass X-ray Binaries in Early-Type Galaxies: Evidence for a Stellar Age Dependence
• Probing the Low-Luminosity XLF in Normal Elliptical Galaxies
• The X-ray luminosity function of low mass X-ray binaries in early-type galaxies, their metal-rich, and metal-poor globular clusters
• Demonstrating the likely neutron star nature of five M31 globular cluster sources with Swift-NuSTAR spectroscopy