Local Interstellar Neutral Hydrogen sampled in-situ by IBEX
Abstract
Hydrogen gas is the dominant component of the local interstellar medium. However, due to ionization and interaction with the heliosphere, direct sampling of the neutral material is more difficult than sampling the local interstellar neutral Helium, which penetrates deep into the heliosphere. In this paper we report on the first direct sampling of the neutral Hydrogen component of the local interstellar medium. We confirm that the arrival direction of Hydrogen is offset from the local Helium component. We further report the discovery of a variation of the penetrating Hydrogen over the first two years of IBEX observations. The observations are consistent with the Hydrogen having an effective ratio of outward solar radiation pressure to inward gravitational force greater than unity (mu>1), and the temporal change observed in the local interstellar hydrogen is consistent with solar variability as the cause.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2011
- Bibcode:
- 2011AGUFMSH23B1957S
- Keywords:
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- 2151 INTERPLANETARY PHYSICS / Neutral particles;
- 7500 SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7800 SPACE PLASMA PHYSICS