AGU 1999 Fall Meeting,

Session SH11C-08, December 13, 1999, Monday, 10:35 a.m.,

Location: MC 302

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Interstellar Hydrogen Atom Distribution Function in the Outer Heliosphere

Vlad Izmodenov1, Mike Gruntman1, Yury Malama2

1 University of Southern California, Los Angeles  E-mails: izmodeno@spock.usc.edu, mikeg@spock.usc.edu

2 Institute for Problems in Mechanics, Russian Academy of Sciences, Moscow, Russia


Objectives

To explore the evolution (due to plasma-neutrals charge exchange coupling) of the interstellar atom velocity distribution in the heliospheric interface.

Statement of Work

We use the Baranov-Malama model of the solar wind - LISM interaction to calculate the velocity distributions of the interstellar hydrogen atoms in the heliospheric interface.

Model

Numerical Methods Results


 
 
 

Locations of points, where velocity distribution has been calculated
 

A. Velocity distribution of the original interstellar atoms
B. Velocity distribution of the secondary interstellar atoms
     created by charge exchange with protons of disturbed
     interstellar plasma (in region 3).
C. Velocity distribution of the H atoms created in the heliosheath
     (region 2) by charge exchange with postshock solar wind
     protons.
D. Velocity distribution of the H atoms created in the supersonic
     solar wind (region 1).

 

A. Velocity distribution of the original interstellar atoms
B. Velocity distribution of the secondary interstellar atoms
     created by charge exchange with protons of disturbed
     interstellar plasma (in region 3).
C. Velocity distribution of the H atoms created in the heliosheath
     (region 2) by charge exchange with postshock solar wind
     protons.
D. Velocity distribution of the H atoms created in the supersonic
     solar wind (region 1).

Conclusions

The velocity distribution of interstellar atoms is not Maxwellian anywhere in the heliospheric interface. The charge exchange process has essentially kinetic consequences on the atom velocity distribution.

In particular,

Acknowledgements. This work was partially supported by NASA Grant NAG5-6966, NSF/NATO Fellowship, INTAS-CNES cooperation Grant # 97512 and ISSI in Bern.