DIFFUSE EMISSION MEASUREMENT WITH THE SPECTROMETER ON INTEGRAL AS AN INDIRECT PROBE OF COSMIC-RAY ELECTRONS AND POSITRONS

Journal Article · Tue Sep 20 00:00:00 EDT 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/739/1/29; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21587531

Bouchet, Laurent; Jourdain, Elisabeth; Roques, Jean-Pierre ^[1]; Strong, Andrew W ^[2]; Porter, Troy A

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1. Universite de Toulouse, UPS-OMP, IRAP, Toulouse (France)
2. Max-Planck-Institut fuer extraterrestrische Physik, Postfach 1603, 85740 Garching (Germany)

Significant advances have been made in the understanding of the diffuse Galactic hard X-ray continuum emission using data from the INTEGRAL observatory. The diffuse hard power-law component seen with the SPectrometer on INTEGRAL (SPI) has been identified with inverse-Compton emission from relativistic (GeV) electrons on the cosmic microwave background and Galactic interstellar radiation field. In the present analysis, SPI data from 2003 to 2009, with a total exposure time of {approx}10{sup 8} s, are used to derive the Galactic ridge hard X-ray spatial distribution and spectrum between 20 keV and 2.4 MeV. Both are consistent with predictions from the GALPROP code. The good agreement between measured and predicted emission from keV to GeV energies suggests that the correct production mechanisms have been identified. We discuss the potential of the SPI data to provide an indirect probe of the interstellar cosmic-ray electron distribution, in particular for energies below a few GeV.

• OSTI ID: 21587531
• Journal Information: Astrophysical Journal, Vol. 739, Issue 1; Other Information: DOI: 10.1088/0004-637X/739/1/29; Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
COSMIC ELECTRONS
COSMIC POSITRONS
EMISSION
GALAXIES
HARD X RADIATION
RELICT RADIATION
SPATIAL DISTRIBUTION
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
COSMIC RADIATION
DISTRIBUTION
ELECTROMAGNETIC RADIATION
ELECTRONS
ELEMENTARY PARTICLES
FERMIONS
IONIZING RADIATIONS
LEPTONS
MATTER
MICROWAVE RADIATION
POSITRONS
RADIATIONS
SECONDARY COSMIC RADIATION
X RADIATION