Gravitational radiation from precessing accretion disks in gamma-ray bursts

ROMERO, G.E.; REYNOSO, M.M.; CHRISTIANSEN, H.R.

ASTRONOMY AND ASTROPHYSICS

EDP SCIENCES S A

Año: 2010 vol. 524 p. 1 - 5

0004-6361

Context. We study the precession of accretion disks in the context of gamma-ray burst inner engines. Aims: Our aim is to quantitatively estimate the characteristics of gravitational waves produced by the precession of the transient accretion disk in gamma-ray bursts. Methods: We evaluate the possible periods of disk precession caused by the Lense-Thirring effect using an accretion disk model that allows for neutrino cooling. Assuming jet ejection perpendicular to the disk plane and a typical intrinsic time-dependence for the burst, we find gamma-ray light curves that have a temporal microstructure similar to that observed in some reported events. The parameters obtained for the precession are then used to evaluate the production of gravitational waves. Results: We find that the precession of accretion disks of outer radius smaller than 108 cm and accretion rates above 1 M_ȯ s-1 could be detected by Advanced LIGO if they occur at distances of less than 100 Mpc. Conclusions: We conclude that the precession of a neutrino-cooled accretion disk in long gamma-ray bursts can be probed by gravitational wave astronomy. Precession of the disks in short gamma-ray events is undetectable with the current technology.