Galactic and extragalactic contributions to the far-ultraviolet background
Data from the 1350--1550 A bandpass channel of the 2/sup 0/.5 angular resolution extreme-ultraviolet telescope on the Apollo-Soyuz mission have been analyzed for stellar airglow radiation contributions for the galactic latitude range Vertical BarbVertical Bar>30/sup 0/. At intermediate latitudes the resulting diffuse background is found to be correlated with the neutral hydrogen column density as determined by 21 cm radio data. This result, together with the observed anisotropy and mean intensity of the radiation field, is consistent with the hypothesis that scattering of galactic-plane starlight off dust grains having an albedo aapprox. =0.5 and a phase function coefficient gapprox. =0.5 is the primary source of the observed radiation field at the intermediate latitudes. The background intensity near the poles is, however, higher than expected from the H I column density and extinction measurements. Taking into account all sources observed during the mission, we find the energy density of the radiation field at 1440 A in the solar neighborhood to be 7.3 +- 3 x 10/sup -17/ ergs cm/sup -3/ A/sup -1/, a value in rough accordance with recent theoretical expectations.
- Research Organization:
- Space Sciences Laboratory, University of California, Berkeley
- OSTI ID:
- 6682003
- Journal Information:
- Astrophys. J.; (United States), Vol. 240:2
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
BACKGROUND RADIATION
FAR ULTRAVIOLET RADIATION
STELLAR RADIATION
SCATTERING
AIRGLOW
COSMIC DUST
COSMIC RADIATION
COSMOLOGY
EMISSION
ENERGY DENSITY
H1 REGIONS
HELIUM IONS
INTERGALACTIC SPACE
INTERSTELLAR GRAINS
RECOMBINATION
CHARGED PARTICLES
COSMIC RADIO SOURCES
DUSTS
ELECTROMAGNETIC RADIATION
IONIZING RADIATIONS
IONS
PARTICLES
RADIATIONS
SPACE
ULTRAVIOLET RADIATION
640101* - Astrophysics & Cosmology- Cosmic Radiation