Characteristics of the helium component of the local interstellar medium

Abstract

view Abstract Citations (73) References (22) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Characteristics of the helium component of the local interstellar medium Weller, C. S. ; Meier, R. R. Abstract Extreme ultraviolet instruments on the Solrad 11B satellite observed helium in the local interstellar medium (LISM) flowing through the solar system through resonantly scattered 584 A solar radiation. Since this satellite orbited the earth at 130,000 km altitude and thus was far removed from the geocoronal airglow, reliable measurements over many directions at a given time were made. As a result, these data, together with hot gas density-resonance scatter computations and previous results, permit accurate determination of quite narrow ranges of LISM velocity (22-28 km/s) and temperature (9,000-15,000 K). The derived LISM helium density of 0.011-0.027/cu cm, when compared with the derived density of the inflowing LISM hydrogen of 0.04-0.06/cu cm, suggests that the local interstellar gas is substantially ionized. Publication: The Astrophysical Journal Pub Date: June 1981 DOI: 10.1086/158936 Bibcode: 1981ApJ...246..386W Keywords: Abundance; Helium; Interstellar Gas; Ultraviolet Spectra; Emission Spectra; Extreme Ultraviolet Radiation; Flow Velocity; Gas Density; Gas Ionization; Gas Temperature; Solar System; Spaceborne Astronomy; Ultraviolet Astronomy; Astrophysics full text sources ADS |