Abstract Details

Conference ID: ASI2017_682
Title : X-ray reprocessing: Through eclipse spectra of High and Low Mass X-ray Binaries
Authors and Co-Authors : Biswajit Paul RAMAN RESEARCH INSTITUTE
Abstract Type : Oral
Abstract Category : Stars,ISM and the Galaxy
Abstract : A difficult aspect of studying reprocessed X-rays in X-ray binary systems is that the reprocessed emission is detected along with the primary emission, which is much brighter. During eclipse, the primary emission is blocked by the companion star and only the reprocessed emission is detected, allowing study of the reprocessing agent. We have studied 9 High Mass X-ray Binaries (Cen X-3, LMC X-4, 4U1538-522, 4U1700-377, IGR J16479-4514, SMC X-1, IGR J18027-2016, IGR J16418-4532, IGR J17252-3616) and one Low Mass X-ray Binary EXO 0748-676 during and outside eclipse with XMM-NEWTON EPIC PN. In the HMXB systems, we have generally found much stronger Fe Kα emission lines in the eclipse spectra compared to the out of eclipse spectra. However, there are some exceptions and there are significant system to system differences. In seven long observations of the LMXB EXO 0748-676, each covering several binary orbits and the eclipses, we have not detected Fe Kα line. The eclipse spectrum in all these observations carried out over a 2 months period show the spectrum to be nearly identical and so is the out-of-eclipse spectrum above 5 keV, indicating a non-varying accretion/emission scenario. However, the out-of-eclipse spectrum below 5 keV shows significant variation. Comparing the eclipse spectra with the out-of-eclipse of these sources, we try to infer the X-ray wind and accretion disk characteristics of these systems, which are the reprocessing agents in the high and low mass X-ray binaries respectively.