EDP Sciences
Free Access
Volume 454, Number 1, July IV 2006
Page(s) 11 - 16
Section Astrophysical processes
DOI https://doi.org/10.1051/0004-6361:20054564

A&A 454, 11-16 (2006)
DOI: 10.1051/0004-6361:20054564

Precession of neutrino-cooled accretion disks in gamma-ray burst engines

M. M. Reynoso1, G. E. Romero2, 3 and O. A. Sampayo1

1  Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3350, (7600) Mar del Plata, Argentina
    e-mail: mreynoso@mdp.edu.ar
2  Instituto Argentino de Radioastronomía, C.C.5, (1894) Villa Elisa, Buenos Aires, Argentina
3  Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Paseo del Bosque, (1900) La Plata, Argentina

(Received 21 November 2005 / Accepted 16 March 2006)

Aims.We study the precession of accretion disks in the context of gamma-ray burst inner engines.
Methods.With an accretion disk model that allows for neutrino cooling, we evaluate the possible periods of disk precession and nutation due to the Lense-Thirring effect.
Results.Assuming jet ejection perpendicular to the disk midplane and a typical intrinsic time dependence for the burst, we find possible gamma-ray light curves with a temporal microstructure similar to what is observed in some subsamples.
Conclusions.We conclude that the precession and nutation of a neutrino-cooled accretion disk in the burst engine might be responsible for some events, especially those with a slow rise and a fast decay.

Key words: gamma-ray: bursts -- accretion, accretion disks -- neutrinos -- black hole physics

© ESO 2006