Accretion onto compact objects

Studies of accretion onto black holes are concerned both with this type of situation and also with accretion happening in active galactic nuclei where the masses of the black holes are typically 10-100 million times greater and the accreting matter is ambient material in the central part of the galaxy rather than coming from a binary companion. Despite the differences in scale, these different types of accretion process have many similarities with the consequence that observations of relatively nearby stellar-mass systems can be used to gain insight into the corresponding processes in the active galactic nuclei.

 Main Projects:

• Non-stationary accretion onto black holes: Use of computer codes, written at SISSA, for making in-depth investigations of non-stationary accretion focussing particularly on limit-cycle behaviour, sonic-point instabilities and disco-seismic modes.


• Advection-dominated flows: Numerical computations to investigate how a transition might occur from a disc-like accretion flow into a hot advection-dominated flow with the inner parts of the disc swelling up in the process.


• Accretion from Oscillating Toroidal Neutron Stars These might be formed by the coalescence of a neutron-star binary leading to a black hole plus an accretion torus with density near to that of nuclear matter. Such a configuration might then be subject to the "runaway" instability. This work has links with gamma-ray bursts and gravitational wave emission.



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People involved:

• Staff Members: J.C. Miller, L. Rezzolla
• Post-docs:
• Ph.D. students: P. Montero
• Main Collaborators: M.A. Abramowicz (Gothenburg), E. Szuszkiewicz (Stettin), L. Zampieri (Padua), V. Karas (Prague), P.A. Charles (Southampton)




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Page created by: L. Rezzolla
Last change: Wed Apr 21 09:14:33 CEST 2004