TY - GEN
T1 - Contribution to the extragalactic gamma-ray background from discrete sources
AU - Bhattacharya, D.
AU - Sreekumar, P.
AU - Mukherjee, R.
PY - 2007
Y1 - 2007
N2 - 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.
AB - 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.
UR - https://www.scopus.com/pages/publications/78649793285
UR - https://www.scopus.com/pages/publications/78649793285#tab=citedBy
U2 - 10.1063/1.2757411
DO - 10.1063/1.2757411
M3 - Conference contribution
AN - SCOPUS:78649793285
SN - 9780735404311
VL - 921
T3 - AIP Conference Proceedings
SP - 480
EP - 481
BT - First GLAST Symposium
T2 - 1st Gamma-ray Large Area Space Telescope Symposium, GLAST
Y2 - 5 February 2007 through 8 February 2007
ER -