HR: 0830h
AN: SH11C-1126    [PDF]
TI: Heliospheric X-Rays and the 1/4 keV Soft X-Ray Background Map
AU: * Robertson, I P
EM: robertin@ku.edu
AF: University of Kansas, Department of Physics & Astronomy, Lawrence, KS 66045-7582 United States
AU: Cravens, T E
EM: cravens@ku.edu
AF: University of Kansas, Department of Physics & Astronomy, Lawrence, KS 66045-7582 United States
AU: Snowden, S L
EM: snowden@riva.gsfc.nasa.gov
AF: Nasa Goddard Spaceflight Center, Code 662, Greenbelt, MD 20771 United States
AB: X-rays are generated throughout the heliosphere as a consequence of charge transfer collisions between heavy solar wind ions and interstellar neutrals. The high charge state solar wind ions resulting from these collisions are left in highly excited states and emit extreme ultraviolet or soft x-ray photons. X-rays are also generated because of charge transfer collisions with neutral hydrogen in the Earth's geocorona. Our model simulates this charge transfer mechanism. It uses the Fahr hot model to determine spatial variations of interstellar helium and hydrogen densities. It also uses published terrestrial exospheric hydrogen distributions and solar wind speed, density and temperature distributions to determine x-ray intensities due to charge transfer with geocoronal hydrogen. We used the same viewing conditions as Snowden [1995] for the 1/4 keV channel soft x-ray background map in galactic coordinates, and produce an analogous heliospheric/geocoronal x-ray intensity map. Our preliminary conclusion is that roughly 50% of the total background soft x-ray intensity in the galactic plane and 25% at high galactic latitudes can be attributed to the charge transfer process operating within the solar system, with the remaining emission coming from outside our heliosphere.
DE: 7554 X rays, gamma rays, and neutrinos
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting