Data di Pubblicazione:
2007
Citazione:
Self-gravitating accretion discs / G. Lodato. - In: LA RIVISTA DEL NUOVO CIMENTO DELLA SOCIETÀ ITALIANA DI FISICA. - ISSN 0393-697X. - 30:7(2007), pp. 293-353. [10.1393/ncr/i2007-10022-x]
Abstract:
I review recent progress in the dynamics and the evolution of selfgravitating
accretion discs. Accretion discs are a fundamental component of several
astrophysical systems on very diverse systems, and can be found in external galaxies
around supermassive black holes in Active Galactic Nuclei (AGN), and also in our
Galaxy around stellar mass compact objects and around young stars. Notwithstanding
the specific differences arising from such diversity in physical extent, all these
systems share a common feature where a central object is fed from the accretion
disc, due to the effect of turbulence and disc instabilities, which are able to remove
the angular momentum from the gas and allow its accretion. In recent years, it
has become increasingly apparent that the gravitational field produced by the disc
itself (the disc’s self-gravity) is an important ingredient in the models, especially
in the context of protostellar discs and of AGN discs. Indeed, it appears that in
many cases (and especially in the colder outer parts of the disc) the development of
gravitational instabilities can be one of the main agents in the redistribution of angular
momentum. In some cases, the instability can be strong enough to lead to the
formation of gravitationally bound clumps within the disc, and thus to determine
the disc fragmentation. As a result, progress in our understanding of the dynamics
of self-gravitating discs is essential to identify the processes that lead to the feeding
of both young stars and of supermassive black holes in AGN. At the same time,
understanding the fragmentation conditions is important to determine under which
conditions AGN discs would fragment and form stars and whether, through disc
fragmentation, protostellar discs might form giant gaseous planets.
Tipologia IRIS:
01 - Articolo su periodico
Elenco autori:
G. Lodato
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