EDP Sciences
Free access
Volume 444, Number 2, December III 2005
Page(s) 417 - 424
Section Extragalactic astronomy
DOI http://dx.doi.org/10.1051/0004-6361:20040527

A&A 444, 417-424 (2005)
DOI: 10.1051/0004-6361:20040527

Cascades of shocks in active galactic nuclei and their radiation

T. J.-L. Courvoisier1, 2 and M. Türler1, 2

1  INTEGRAL Science Data Centre, ch. d'Écogia 16, 1290 Versoix, Switzerland
    e-mail: thierry.courvoisier@obs.unige.ch
2  Geneva Observatory, ch. des Maillettes 51, 1290 Sauverny, Switzerland

(Received 26 March 2004 / Accepted 11 August 2005)

We discuss accretion flows on massive black holes in which different elements of the flow (clumps) have velocities that may differ substantially. We estimate the consequence of collisions between these clumps as they come close to the central object and calculate the resulting radiation. We show that this radiation is similar to that observed in the optical to X-ray spectral domain in Seyfert galaxies and quasars. We also show that the large scale accretion is likely to be clumpy when arriving in the active region and that the clumps keep their identity between collisions.

Key words: accretion, accretion disks -- radiation mechanisms: thermal -- radiation mechanisms: non-thermal -- galaxies: active -- quasars: general

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