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Author Colgate, S. A. ♦ Leonard, P. J.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword PHYSICS ♦ COSMIC GAMMA BURSTS ♦ NEUTRON STARS ♦ MILKY WAY ♦ STAR ACCRETION ♦ ACCRETION DISKS ♦ PLASMA ♦ COSMIC NEUTRINOS ♦ BINARY STARS ♦ MATHEMATICAL MODELS
Abstract What makes a Galactic model of gamma-ray bursts (GBs) feasible is the observation of a new population of objects, fast neutron stars, that are isotropic with respect to the galaxy following a finite period, {approx}30 My, after their formation (1). Our Galactic model for the isotropic component of GBs is based upon high-velocity neutron stars (NSs) that have accretion disks. These fast NSs are formed in tidally locked binaries, producing a unique population of high velocity ({approx_gt}10{sup 3} kms{sup -1}) and slowly rotating (8 s) NSs. Tidal locking occurs due to the meridional circulation caused by the conservation of angular momentum of the tidal lobes. Following the collapse to a NS and the explosion, these lobes initially perturb the NS in the direction of the companion. Subsequent accretion (1 to 2 s) occurs on the rear side of the initial motion, resulting in a runaway acceleration of the NS by neutrino emission from the hot accreted matter. The recoil momentum of the relativistic neutrino emission from the localized, down flowing matter far exceeds the momentum drag of the accreted matter. The recoil of the NS is oriented towards the companion, but the NS misses because of the pre-explosion orbital motion. The near miss captures matter from the companion and forms a disk around the NS. Accretion onto the NS from this initially gaseous disk due to the ``alpha`` viscosity results in a soft gamma-ray repeater phase, which lasts {approx}10{sup 4} yr. Later, after the neutron star has moved {approx}30 kpc from its birthplace, solid bodies form in the disk, and accrete to planetoid size bodies after {approx}3{times}10{sup 7} years. Some of these planetoid bodies, with a mass of {approx}10{sup 21}{endash}10{sup 22} g, are perturbed into an orbit inside the tidal distortion radius of {approx_gt}10{sup 5} km. Of these {approx}1% are captured by the magnetic field of the NS at R{lt}2{times}10{sup 3} km to create GBs.
ISSN 0094243X
Educational Use Research
Learning Resource Type Article
Publisher Date 1996-04-01
Publisher Place United States
Volume Number 366
Issue Number 1
Technical Publication No. CONF-9503269-


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