Studies of the diffuse background and interstellar dust at far ultraviolet wavelengths

Thesis/Dissertation · Mon Jan 01 04:00:00 EST 1990

OSTI ID:5394138

Hurwitz, M V

The diffuse background at wavelengths between 1000 and 2000{Angstrom}, the far ultraviolet band, contains information about the nature of dust in the interstellar medium. Unfortunately, a survey of current literature on this topic reveals widely discrepant observations of the background, and equally varied reports as to the parameters that describe the scattering properties of interstellar dust grains. The data analyzed have two enormous advantages over those used by previous researchers: the instrument design provided for elimination of virtually all sources of contamination (including point sources, out-of-band and out-of-field scattering, and detection dark current), and the data are spectroscopic, allowing the various astrophysical processes which contribute to the background to be identified and treated independently. The model used to extract the scattering properties of the dust from the observations is also superior to those previously employed, for the following reasons: the source function for the scattered light is allowed to vary along the line of sight, the stellar radiation field which illuminates the grains is based on a realistic distribution of stars and dust in the Galaxy, and the radiative transfer is valid for large optical depths. These advantages permit the analysis of low-altitude, high-column density targets, which are shown to be crucial in determining the scattering properties of the grains.

• Research Organization: California Univ., Berkeley, CA (United States)
• OSTI ID: 5394138
• Country of Publication: United States
• Language: English

Related Subjects

640101* -- Astrophysics & Cosmology-- Cosmic Radiation
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COSMIC DUST
DATA
DUSTS
ELECTROMAGNETIC RADIATION
EXPERIMENTAL DATA
FAR ULTRAVIOLET RADIATION
INFORMATION
NUMERICAL DATA
POINT SOURCES
RADIATION SOURCES
RADIATIONS
SCATTERING
SPECTRA
STELLAR RADIATION
ULTRAVIOLET RADIATION
ULTRAVIOLET SPECTRA