One- vs. Two-Shock Heliosphere: Constraining Models with GHRS LyA Spectra toward alpha Cen

dc.creatorGayley, K. G.
dc.creatorZank, G. P.
dc.creatorPauls, H. L.
dc.creatorFrisch, P. C.
dc.creatorWelty, D. E.
dc.date1997-06-04
dc.date.accessioned2026-07-25T20:24:36Z
dc.descriptionRedshifted L$α$ absorption toward $α$ Cen has been interpreted by Linsky & Wood (1996) and Frisch et al. (1996) as evidence for decelerated interstellar hydrogen piled up on the upstream side of the heliosphere. We utilize newly developed two-dimensional multi-fluid models of the solar wind interaction with the ISM to corroborate this interpretation by synthesizing the L$α$ absorption profile predicted for this ``hydrogen wall''. Both subsonic and supersonic inflow into the heliosphere are considered, corresponding to one-shock and two-shock global morphologies, respectively. It is found that these two extremes give observably different redward absorption characteristics in the L$α$ profiles, and our preliminary conclusion is that the L$α$ profiles seen toward $α$ Cen favor a barely subsonic model (Mach number 0.9). For such a model to hold, additional interstellar pressure terms, such as cosmic ray or magnetic pressures, must contribute. To make this conclusion more certain, an extended model-parameter survey is required, coupled with L$α$ data along other lines of sight.
dc.identifierhttps://arxiv.org/abs/astro-ph/9706043
dc.identifierhttp://arxiv.org/abs/astro-ph/9706043
dc.identifier.urihttps://dspace.dare.co.zw/handle/123456789/70830
dc.subjectAstrophysics
dc.titleOne- vs. Two-Shock Heliosphere: Constraining Models with GHRS LyA Spectra toward alpha Cen
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