Diffuse galactic gamma radiation: The Compton contribution and component separation by energy interval and galactic coordinates

Journal Article · Sun Nov 01 04:00:00 EST 1981 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/159387· OSTI ID:5609945

Kniffen, D A; Fichtel, C E

The diffuse high-energy galactic ..gamma..-radiation to be expected from cosmic interactions with matter and photons is examined. Particular emphasis is placed on the Compton emission since work in this area is hindered by the limited knowledge of the galactic photon densities. Both the photon density in and near the visible region and that in the infrared region are deduced from the estimates of the emission functions throughout the Galaxy. The blackbody radiation is also included in the estimate of the total Compton emission. The result suggests that the ..gamma..-ray Compton radiation from cosmic ray interactions with galactic visible and infrared photons is substantially larger than previously believed. The analysis of the energy spectra and latitude dependence shows further than the Compton radiation, the bremsstrahlung, and the nuclear cosmic ray--matter interaction radiation should be separable by the study of appropriate energy intervals and latitude regions, where there are no major point source contributions. The experimental results, even though limited, give encouragement that the basic concepts and assumptions are likely to be correct and the future ..gamma..-ray results will be very helpful in defining galactic structure, determining the relative importance of cosmic ray electrons in the Galaxy, estimating the intensity and pressure effects of cosmic rays in other parts of the Galaxy, and aid, in conjunction with radio data, in determining the galactic photon density at least within a few kiloparsecs, as well as setting limits in the galactic center region.

• Research Organization: NASA Goddard Space Flight Center
• OSTI ID: 5609945
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 250:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640101* -- Astrophysics & Cosmology-- Cosmic Radiation
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BASIC INTERACTIONS
BLACKBODY RADIATION
BREMSSTRAHLUNG
COMPTON EFFECT
COSMIC GAMMA SOURCES
COSMIC RADIATION
COSMIC RAY SOURCES
ELASTIC SCATTERING
ELECTROMAGNETIC INTERACTIONS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
EMISSION
ENERGY SPECTRA
GALAXIES
GAMMA RADIATION
INTERACTIONS
IONIZING RADIATIONS
MASSLESS PARTICLES
MILKY WAY
PHOTONS
RADIATIONS
SCATTERING
SPECTRA