Computation of Mass Outflow Rate from Relativistic Quasi-Spherical Accretion onto Black Hol.pdf

a r X i v : a s t r o - p h / 9 8 1 1 4 1 5 v 2 9 A p r 1 9 9 9 Mon. Not. R. Astron. Soc. 000, 000–000 (0000) Printed 1 February 2008 (MN LATEX style file v1.4) Computation of Mass Outflow Rate from Relativistic Quasi-Spherical Accretion onto Black Holes Tapas K. Das Theoretical Astrophysics Group S. N. Bose National Centre For Basic Sciences Block JD Sector III Salt Lake Calcutta 700 091 India E-mail tdas@boson.bose.res.in Accepted 08.04.99 Received 07.12.98. ; in original form 07.12.98 ABSTRACT We compute mass outflow rate Rm? from relativistic matter accreting quasi-spherically onto Schwarzschild black holes. Taking the pair-plasma pressure mediated shock sur- face as the effective boundary layer (of the black hole) from where bulk of the outflow is assumed to be generated, computation of this rate is done using combinations of exact transonic inflow and outflow solutions. We find that Rm? depends on the initial parameters of the flow, the polytropic index of matter, the degree of compression of matter near the shock surface and on the location of the shock surface itself. We thus not only study the variation of the mass outflow rate as a function of various physical parameters governing the problem but also provide a sufficiently plausible estimation of this rate. Key words: AGN – quasars – jets – accretion, accretion discs – black hole physics – shock-waves – hydrodynamics – outflow – wind To appear in MNRAS 1 INTRODUCTION Computation of mass outflow rates from the advective accretion disks around black holes and neutron stars very re- cently has been done (Chakrabarti, 1998; Das, 1998, 1998a; Das Chakrabarti, 1998 [DC98 hereafter]). by self consis- tently combining the exact transonic accretion and wind solutions. Rigoriously justifying the fact that most of the outflowing matter comes out from the CENtrifugal Pressure Supported BOundary Layer (CENBOL) it has been shown there that the Rankine-Hugoniot shock location or the loca- tion of the maximum polyt