Estimation of mass outflow rates from dissipative accretion disc around rotating black holes

Aktar, Ramiz and Das, Santabrata and Nandi, Anuj and Sreehari, H (2017) Estimation of mass outflow rates from dissipative accretion disc around rotating black holes. In: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 471 (4). pp. 4816-4829.

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Abstract

We study the properties of the dissipative accretion flow around rotating black holes in the presence of mass loss. We obtain a complete set of global inflow-outflowsolutions in the steady state by solving the underlying conservation equations self-consistently. We observe that global inflow-outflow solutions are not the isolated solution, instead such solutions are possible for wide range of inflow parameters. Accordingly, we identify the boundary of the parameter space for outflows, spanned by the angular momentum (lambda(in)) and the energy (epsilon(in)) at the inner sonic point (chi(in)), as a function of the dissipation parameters and find that parameter space gradually shrinks with the increase of dissipation rates. Further, we examine the properties of the outflow rate R-m (defined as the ratio of the outflow-to-inflow mass flux) and ascertain that dissipative processes play a decisive role in determining the outflow rates. We calculate the limits on the maximum outflow rate (R-m(max)) in terms of viscosity parameter (a) as well as the black hole spin (a(k)) and obtain the limiting range as 3 per cent <= R-m(max) <= 19 per cent. Moreover, we calculate the viable range of a that admits the coupled inflow-outflow solutions and find that alpha less than or similar to 0.25 for R-m not equal 0. Finally, we discuss the observational implication of our formalism to infer the spin of the black holes. Towards this, considering the highest observed quasi-periodic oscillation frequency of the black hole source GRO J1655-40 (similar to 450 Hz), we constrain the spin value of the source as a(k) >= 0.57.

Item Type:	Journal Article
Publication:	MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
Additional Information:	Copy right for this article belongs to the OXFORD UNIV PRESS, GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND
Department/Centre:	Division of Physical & Mathematical Sciences > Joint Astronomy Programme
Date Deposited:	13 Oct 2017 04:53
Last Modified:	13 Oct 2017 04:53
URI:	http://eprints.iisc.ac.in/id/eprint/58004

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