Feeding a gamma-ray burster

Journal Article · Mon Apr 15 04:00:00 EST 1985 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/163118· OSTI ID:5315749

Epstein, R I

The energetics of a ..gamma..-ray burster can be explained by the rapid accretion of > or approx. =10/sup 19/ g of matter onto a neutron star surface. It is proposed that this sudden infall of matter may be the result of a radiation-driven instability which occurs at the boundary between an accretion disk and the surface of a slowly rotating neutron star. The observed ..gamma..-ray burst intensities require that the surface densities in the inner regions of the accretion disks exceed about 10/sup 8/ g cm/sup -2/. It is conjectured that disks with this property could form from the tidal breakup of planets that were thrown into eccentric orbits following the explosions that created the neutron stars. During an outburst, the boundary instability depletes the materials from the inner edge of an accretion disk, and between outbursts this material is replenished by the mass flow that is driven by the viscosity in the disk. The long interval between bursts indicates that the mean mass accretion rate is very slow. This suggests that the flow in the disk is laminar and that the main source of dissipation and angular momentum transport is molecular viscosity. Such disks are found to be dense and relatively cool and to contain highly degenerate electrons which furnish most of the pressure and viscosity. This model yields estimates for the recurrence time for bursts, for the steady emission from the accretion disks, and for the flux of reprocessed radiation that is emitted during outbursts. These estimates are consistent with observations of the 1978 November 19 burster and the 1979 March 5 burster if the former is a few hundred pc from the solar system and if the latter is located in the LMC.

• Research Organization: Los Alamos National Laboratory
• OSTI ID: 5315749
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 291:2; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640103* -- Astrophysics & Cosmology-- Quasi-Stellar
Radio
& X-Ray Sources-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANGULAR MOMENTUM
COSMIC GAMMA BURSTS
COSMIC RADIATION
DISSIPATION FACTOR
FLUID FLOW
INSTABILITY
IONIZING RADIATIONS
LAMINAR FLOW
MAGNETIC FIELDS
MATHEMATICAL MODELS
NEUTRON STARS
PLANETS
PLASMA
PRIMARY COSMIC RADIATION
RADIATIONS
STAR ACCRETION
STAR BURNING
STAR EVOLUTION
STAR MODELS
STARS
STELLAR RADIATION
TORQUE
VISCOSITY