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

REYNOSO, M. M.; ROMERO, G. E.; SAMPAYO, O. A.

ASTRONOMY AND ASTROPHYSICS

Año: 2006 vol. 454 p. 11 - 16

0004-6361

 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.