Interaction of the Expanding Atmosphere with the Stellar Wind around Gliese 436b

Abstract

Numerical modeling results of interactions of the planetary atmosphere of Gliese 436b with ionizing radiation and the plasma wind of an M star are presented. A self-consistent gas-dynamic 2D model characterizing the processes of radiation heating and ionization and hydrogen photochemistry reactions was used in the modeling. It is demonstrated that Gliese 436b should have an extended (several tens of planetary radii) exosphere, which is formed by partially ionized gas with added molecular components, with a supersonic outflow velocity. The influence of such factors as the XUV radiation intensity and the temperature of the lower atmosphere on the mass loss rate is examined.