Abstract Details
| Name: BARI Affiliation: DEPARTMENT OF PHYSICS,KASHMIR UNIVERSITY SRINAGAR Conference ID: ASI2015_864 Title : The Effect of X-ray Irradiation on the Time Dependent behavior of Accretion Disks with Stochastic Perturbations. Authors and Co-Authors : Bari Maqbool,Ranjeev Misra, Naseer Iqbal Abstract Type : Poster Abstract Category : Extragalactic astronomy Abstract : The UV emission from X-ray binaries, may arise from the outer regions of an accretion disk. The structure of the outer disk may be altered due to the presence of X-ray irradiation and we discuss the physical regimes where this may occur and point out certain X-ray binaries where this effect may be important. The long term X-ray variability of these sources is believed to be due stochastic fluctuations in the outer disk, which propagate inwards giving rise to accretion rate variation in the X-ray producing inner regions. The X-ray variation will induce structural variations in the outer disk which in turn may affect the inner accretion rate. To understand the qualitative behavior of the disk in such a scenario, we adopt simplistic assumptions that the disk is fully ionized and is not warped. We develop and use a time dependent global hydrodynamical code to study the effect of a sinusoidal accretion rate perturbation introduced as a specific radius. The response of the disk, especially the inner accretion rate, to such perturbations at different radii and with different time periods is quantified. While we didn't find any oscillatory or limit cycle behavior, our results show irradiation enhances the X-ray variability at time-scales corresponding to the viscous time-scales of the irradiated disk. |