Contribution to the extragalactic gamma-ray background from discrete sources

D. Bhattacharya, P. Sreekumar, R. Mukherjee

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The extragalactic gamma ray background (EGRB) could arise from two distinct scenarios: truly diffuse processes or from unresolved point sources. Here we examine contribution from unresolved normal galaxies, starburst galaxies and AGNs. γ-ray emission from normal galaxies is mostly due to cosmic ray interactions with interstellar matter and radiation. Though no starburst galaxy has been detected so far in γ-rays, enhanced supernovae activity is expected to lead to higher cosmic ray densities, making starburst galaxies sufficiently γ-ray luminous to be detected by GLAST, γ-rays from blazars are believed to arise from relativistic jets. The γ-ray emission is expected to decrease with increasing jet inclination angle. The γ-ray detection of Cen A and NGC 6251 suggests, other sub-classes of AGNs could also be potential contributors to the γ-ray background. Preliminary results are discussed.

Original languageEnglish
Title of host publicationFirst GLAST Symposium
Pages480-481
Number of pages2
Volume921
DOIs
Publication statusPublished - 2007
Event1st Gamma-ray Large Area Space Telescope Symposium, GLAST - Stanford, CA, United States
Duration: 05-02-200708-02-2007

Conference

Conference1st Gamma-ray Large Area Space Telescope Symposium, GLAST
CountryUnited States
CityStanford, CA
Period05-02-0708-02-07

Fingerprint

rays
gamma rays
starburst galaxies
cosmic rays
interstellar radiation
interstellar matter
galaxies
Fermi Gamma-ray Space Telescope
blazars
point sources
inclination
supernovae
interactions

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Cite this

Bhattacharya, D., Sreekumar, P., & Mukherjee, R. (2007). Contribution to the extragalactic gamma-ray background from discrete sources. In First GLAST Symposium (Vol. 921, pp. 480-481) https://doi.org/10.1063/1.2757411
Bhattacharya, D. ; Sreekumar, P. ; Mukherjee, R. / Contribution to the extragalactic gamma-ray background from discrete sources. First GLAST Symposium. Vol. 921 2007. pp. 480-481
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Bhattacharya, D, Sreekumar, P & Mukherjee, R 2007, Contribution to the extragalactic gamma-ray background from discrete sources. in First GLAST Symposium. vol. 921, pp. 480-481, 1st Gamma-ray Large Area Space Telescope Symposium, GLAST, Stanford, CA, United States, 05-02-07. https://doi.org/10.1063/1.2757411

Contribution to the extragalactic gamma-ray background from discrete sources. / Bhattacharya, D.; Sreekumar, P.; Mukherjee, R.

First GLAST Symposium. Vol. 921 2007. p. 480-481.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

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Bhattacharya D, Sreekumar P, Mukherjee R. Contribution to the extragalactic gamma-ray background from discrete sources. In First GLAST Symposium. Vol. 921. 2007. p. 480-481 https://doi.org/10.1063/1.2757411