Non-linear behaviour of the black hole system GRS 1915+ 105

Abstract

Using non-lin~ar ti?Ie seri.e~ analysis, along with surrogate data analysis, it is shown that the various types of lon~ t~rI? varla~lbty exhibited by the black hole system GRS 1915+105, can be explained in terms of a ~et~rmlmstlc.n?n-bnear system with some inherent stochastic noise. Evidence is provided for a non-linear limit cycle ongm of one of.the low f~eque~cy QPO detected in the source, while some other types of variability could. be due ~oan underlying low dimensional chaotic system. These results imply that the partial differential equanons which govern the magneto- ~drodynamic flow of the inner accretion disk, can be approximated by a by a small number ( ~ 3 - 5) of non-linear but ordinary differential equations. While this analysis does not reveal the exact nature of these approximate equations, they may be obtained in the future, after results of magneto-hydrodynamic simulation of realistic accretion disks become available.