The Megasecond Chandra X-Ray Visionary Project Observation of NGC 3115 (II): properties of point sources

摘要: We have carried out an in-depth study of low-mass X-ray binaries (LMXBs) detected in the nearby lenticular galaxy NGC 3115, using Megasecond Chandra X-Ray Visionary Project observation (total exposure time 1.1 Ms). In total we found 136 candidate LMXBs field and 49 globular clusters (GCs) above 2\sigma\ detection, with 0.3--8 keV luminosity L_X ~10^36-10^39 erg/s. Other than 13 transient candidates, sources overall less long-term variability at higher luminosity, least > 2x10^37 order to identify nature spectral state our sources, compared their collective properties based on single-component models (a simple power law or a multicolor disk) evolution seen representative Galactic LMXBs. that versus photon index \Gamma_PL disk temperature kT_MCD plots, most fall narrow track which shape hardens increasing below L_X~7x10^37 erg/s but is relatively constant (\Gamma_PL~1.5 kT_MCD~1.5 keV) this similar neutron star (NS) soft bandpass. Therefore identified as NS LMXB soft-state suggested 7x10^37 Z sources. Ten other (five are transients) displayed significantly softer spectra probably black hole thermal state. One them (persistent) metal-poor GC.