H Atom Velocity Distributions in Heliospheric Interface

V. V. Izmodenov (1), Yu. G. Malama (3), M. Gruntman (3), R. Lallement (4)

(1) Department of Aeromechanics and Gas Dynamics, Faculty of Mechanics and Mathematics, Lomonosov Moscow State University, Vorob'evy Gory, Moscow, 119899, Russia, izmod@ipmnet.ru/Fax: +7-095-9382048; (2) Institute for Problems in Mechanics, Moscow, Russia; (3) University of Southern California, Los Angeles, California; (4) Service d'Aéronomie, Verrieres-le-Buisson, France

We study evolution of the velocity distribution function of interstellar neutral gas in the heliospheric interface, the region of the solar and interstellar wind interaction. We numerically solve the kinetic equation for neutral gas self-consistently with hydrodynamical equations for plasma. Neutral and plasma components interact by charge-exchange. This interaction disturbs of atom velocity distribution, which is assumed Maxwellian in the circumsolar interstellar medium. To describe a complex of velocity distribution of interstellar atoms in the heliospheric interface we introduce three atom populations in addition to the primary interstellar neutrals. We present velocity distributions of these populations and discuss their kinetic properties.