Title:
Numerical modeling of the nonequilibrium flow of a rarefied gas in the inner coma of a comet
Authors:
Bisikalo, D. V.; Shematovich, V. I.
Affiliation:
AB(AN SSSR, Astronomicheskii Sovet, Moscow, USSR)
Journal:
Astronomicheskii Vestnik (ISSN 0320-930X), vol. 22, Jan.-Mar. 1988, p. 41-48. In Russian.
Publication Date:
03/1988
Category:
Astrophysics
Origin:
STI
NASA/STI Keywords:
COMET HEADS, NONEQUILIBRIUM FLOW, RAREFIED GAS DYNAMICS, HALLEY'S COMET, HYDROGEN, HYDROXYL RADICALS, NONEQUILIBRIUM THERMODYNAMICS, WATER VAPOR
Bibliographic Code:
1988AVest..22...41B

Abstract

The velocity distribution functions of the gas components of an inner coma consisting of H2O vapor and its photolysis products are calculated for a comet with a medium gas production rate (e.g., Comet Halley) at a heliocentric distance of 1 AU. The radial profiles of the macroscopic parameters of H2O, OH, and H are then obtained for the spherically symmetric outflow. It is shown that the breakdown of the local thermodynamic equilibrium for the gas of parent molecules (H2O) begins very close to the nucleus.