EDP Sciences
Free access
Volume 379, Number 2, November IV 2001
Page(s) 683 - 689
Section Physical and chemical processes
DOI http://dx.doi.org/10.1051/0004-6361:20011307

A&A 379, 683-689 (2001)
DOI: 10.1051/0004-6361:20011307

Computation of outflow rates from accretion disks around black holes

S. Das, I. Chattopadhyay, A. Nandi and S. K. Chakrabarti

S. N. Bose National Centre for Basic Sciences, Salt Lake, Kolkata 700098, India

(Received 15 May 2001 / Accepted 30 August 2001 )

We self-consistently estimate the outflow rate from the accretion rates of an accretion disk around a black hole in which both the Keplerian and the sub-Keplerian matter flows simultaneously. While Keplerian matter supplies soft-photons, hot sub-Keplerian matter supplies thermal electrons. The temperature of the hot electrons is decided by the degree of inverse Comptonization of the soft photons. If we consider only thermally-driven flows from the centrifugal pressure-supported boundary layer around a black hole, we find that when the thermal electrons are cooled down, either because of the absence of the boundary layer (low compression ratio), or when the surface of the boundary layer is formed very far away, the outflow rate is negligible. For an intermediate size of this boundary layer the outflow rate is maximal. Since the temperature of the thermal electrons also decides the spectral state of a black hole, we predict that the outflow rate should be directly related to the spectral state.

Key words: X-rays: stars -- stars: winds, outflows -- black hole physics

Offprint request: S. K. Chakrabarti, chakraba@boson.bose.res.in

© ESO 2001