HR: 0830h
AN: SH11C-1123    [PDF]
TI: ROSAT X-ray Observations of the Primary and Secondary Streams of Interstellar Neutral Atoms
AU: * Collier, M R
EM: mcollier@pop600.gsfc.nasa.gov
AF: NASA, GSFC, Greenbelt, MD 20771 United States
AU: Snowden, S
EM: snowden@riva
AF: NASA, GSFC, Greenbelt, MD 20771 United States
AU: Moore, T E
EM: thomas.e.moore@gsfc.nasa.gov
AF: NASA, GSFC, Greenbelt, MD 20771 United States
AU: Simpson, D
EM: david.simpson@gsfc.nasa.gov
AF: NASA, GSFC, Greenbelt, MD 20771 United States
AU: Pilkerton, B
EM: bpilkerton@lepvax.gsfc.nasa.gov
AF: NASA, GSFC, Greenbelt, MD 20771 United States
AU: Fuselier, S
EM: fuselier@mail.spasci.com
AF: Space Physics Lab, LMATC, 3251 Hanover St., Palo Alto, CA 94304 United States
AU: Wurz, P
EM: peter.wurz@soho.unibe.ch
AF: University of Bern, Physics Department, Bern, CH-301 Switzerland
AB: Heavy neutral atoms entering the heliosphere from the interstellar wind are focused downstream of the Sun into a focusing cone, creating a region of enhanced neutral density. Solar wind high charge state ions charge exchange with these neutrals and, in the process, emit soft X-rays ($\sim$0.25 keV). In this presentation, we discuss ROSAT X-ray observations of both the primary and secondary streams of interstellar neutral atoms [Collier et al., Adv. Space Res., in press, 2003]. Results of the analysis indicate a value of $\alpha$ consistent with about 6x10${}^{-16}$ eV cm${}^2$ (e.g. Cravens, T.E., Ap. J., 532:L153, 2000, eq. 2), a heliospheric contribution to the total X-ray flux ranging from about 18% at about five-ten degrees off the downstream axis to about 40% directly above the downstream axis viewing southward, and a secondary stream entering the heliosphere from above the ecliptic plane which may contain 3-4 times more neutral density at 1 AU than the primary stream, at least during the time of the ROSAT All-Sky Survey. The origin, properties and implications of this secondary stream need to be examined before we can have any confidence that our understanding of the heliosphere is not flawed.
DE: 5757 Remote sensing
DE: 7554 X rays, gamma rays, and neutrinos
DE: 7837 Neutral particles
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting