Use of the Egret instrument in studies of the origin of the cosmic radiation
Abstract
This is a continuation of previous studies aimed at predicting spectral signatures of discrete cosmic-ray sources. In this paper, a formalism is developed for calculating gamma-ray spectra observed at Earth from the decay of neutral pions formed in collisions of cosmic-ray protons and ions with galactic gas and dust. The cosmic rays are assumed to be emitted by discrete sources, and their intensities and spectra are described by solutions to a diffusion equation. Calculations of spectral signatures expected from these hypothetical point sources of cosmic rays are presented. In particular, a steady source of cosmic rays could show a harder gamma-ray spectrum than the spectrum of the diffuse galactic background, whereas an impulsive source of cosmic rays could show a much softer spectrum. Observations of the angular variations of gamma-ray intensities and spectra near point sources will provide information on cosmic-ray propagation in other parts of our galaxy, as well as on the nature of the discrete sources themselves. Capabilities of the Egret telescope in mapping spectra from cosmic-ray point sources are briefly discussed. 14 refs., 2 figs.
- Authors:
- Publication Date:
- Research Org.:
- Lawrence Livermore National Lab., CA (USA)
- Sponsoring Org.:
- DOE/DP
- OSTI Identifier:
- 5356237
- Report Number(s):
- UCRL-102243; CONF-900129-4
ON: DE90003595; TRN: 90-000470
- DOE Contract Number:
- W-7405-ENG-48
- Resource Type:
- Conference
- Resource Relation:
- Conference: 21. international cosmic ray conference, Adelaide (Australia), 6-19 Jan 1990
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; GAMMA SPECTRA; CALCULATION METHODS; COSMIC GAMMA SOURCES; MEASURING INSTRUMENTS; TELESCOPES; COSMIC RAY SOURCES; SPECTRA; 640101* - Astrophysics & Cosmology- Cosmic Radiation
Citation Formats
Dermer, C D. Use of the Egret instrument in studies of the origin of the cosmic radiation. United States: N. p., 1989.
Web.
Dermer, C D. Use of the Egret instrument in studies of the origin of the cosmic radiation. United States.
Dermer, C D. 1989.
"Use of the Egret instrument in studies of the origin of the cosmic radiation". United States. https://www.osti.gov/servlets/purl/5356237.
@article{osti_5356237,
title = {Use of the Egret instrument in studies of the origin of the cosmic radiation},
author = {Dermer, C D},
abstractNote = {This is a continuation of previous studies aimed at predicting spectral signatures of discrete cosmic-ray sources. In this paper, a formalism is developed for calculating gamma-ray spectra observed at Earth from the decay of neutral pions formed in collisions of cosmic-ray protons and ions with galactic gas and dust. The cosmic rays are assumed to be emitted by discrete sources, and their intensities and spectra are described by solutions to a diffusion equation. Calculations of spectral signatures expected from these hypothetical point sources of cosmic rays are presented. In particular, a steady source of cosmic rays could show a harder gamma-ray spectrum than the spectrum of the diffuse galactic background, whereas an impulsive source of cosmic rays could show a much softer spectrum. Observations of the angular variations of gamma-ray intensities and spectra near point sources will provide information on cosmic-ray propagation in other parts of our galaxy, as well as on the nature of the discrete sources themselves. Capabilities of the Egret telescope in mapping spectra from cosmic-ray point sources are briefly discussed. 14 refs., 2 figs.},
doi = {},
url = {https://www.osti.gov/biblio/5356237},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Oct 27 00:00:00 EDT 1989},
month = {Fri Oct 27 00:00:00 EDT 1989}
}