SOME REQUIREMENTS OF A COLLIDING COMET SOURCE OF GAMMA-RAY BURSTS

Colliding comets in the Solar System may be an important source of gamma ray bursts. The spherical gamma ray comet cloud required by the results of the Venera Satellites (Mazets and Golenetskii, 1987) and the BATSE detector on the Compton Satellite (Meegan et al., 1992a, b) is neither the Oort Cloud nor the Kuiper Belt. To satisfy observations of N(> P(max)) vs P(max) for the maximum gamma ray fluxes, P(max) > 10(-5) erg cm-2 s-1 (about 30 bursts yr-1), the comet density, n, should increase as n approximately a1 from about 40 to 100 AU where a is the comet heliocentric distance. The turnover above 100 AU requires n approximately a-1/2 to 200 AU to fit the Venera results and n approximately a1/4 to 400 AU to fit the BATSE data. Then the masses of comets in the 3 regions are from: 40-100 AU, about 9 earth masses, m(E); 100-200 AU about 25 m(E); and 100-400 AU, about 900 m(E). The flux of 10(-5) erg cm-2 s-1 corresponds to a luminosity at 100 AU of 3 x 10(26) erg s-1. Two colliding spherical comets at a distance of 100 AU, each with nucleus of radius R of 5 km, density of 0.5 g cm-3 and Keplerian velocity 3 km s-1 have a combined kinetic energy of 3 x 10(28) erg, a factor of about 100 greater than required by the burst maximum fluxes that last for one second. Betatron acceleration in the compressed magnetic fields between the colliding comets could accelerate electrons to energies sufficient to produce the observed high energy gamma rays. Many of the additional observed features of gamma ray bursts can be explained by the solar comet collision source.