Abstract Details

Name: DR. Broja Gopal Dutta
Affiliation: RBC College, (West Bengal State University), Naihati, North Twenty Four Parganas, W.B., 743165
Conference ID: ASI2017_820
Title : Implication of disk inclination on Hard and Soft lags in binary systems
Authors and Co-Authors : Broja Gopal Dutta1,2 and Sandip K. Chakrabarti3,2 1. Rishi Bankim Chandra College, Naihati, North Twenty Four Parganas, 743165, W.B, India 2. S.N. Bose National Centre for Basic Sciences, Sector-III, Saltlake, Kolkata-700098, India 3. Indian Centre for Space Physics, 43 Chalantika, Garia Station Road, Kolkata 700084, India
Abstract Type : Oral
Abstract Category : Stars,ISM and the Galaxy
Abstract : We study the lag properties from fast variability in X-ray emission high inclination (XTE J1550-564) and low inclination (GX 339-4) black hole sources during outbursts. It is clearly observed in both high and low inclination systems that the lag increases when QPO frequency goes down, i.e., when the size of the Comptonizing region goes up. In fact, exactly opposite result is found also in the declining phase. We find that (Dutta & Chakrabarti, 2016) the time lag is not only a function of the average energy of the emitted photons, it is also a function of the inclination angle of the binary system. We explain the hard and soft lags are due to the effects of (i) repeated Compton scattering which accounts higher lags (hard) for higher-energy photons and for Compton clouds of larger size before they escape, (ii) reflection, and (iii) focusing due to gravitational bending. Specifically, we showed that if we add up the qualitative variations of the lag components, then the high inclination objects could have negative time lags, i.e., soft photons appearing after hard photons due to reflection and focusing effects. We explain lag-behaviour within the framework of a single two component advective flow model. Reference; 1.Dutta, Broja. G., Chakrabarti, S. K., Astro Physical Journal (ApJ), 2016, Vol. 828: 110 (8pp), 2016