Can the extragalactic gamma-ray background be explained by AGN?

Tanja M. Kneiske; Karl Mannheim; Lukasz Stawarz; Jun Kataoka

doi:10.1063/1.3076721

Can the extragalactic gamma-ray background be explained by AGN?

Tanja M. Kneiske, Karl Mannheim, Lukasz Stawarz, Jun Kataoka

Research output: Contribution to journal › Conference article › peer-review

Abstract

Very high energy gamma-rays from blazars traversing cosmological distances through the meta-galactic radiation field can convert into electron-positron pairs in photon-photon collisions. The converted gamma-rays initiate electromagnetic cascades driven by inverse-Compton scattering with microwave background photons. Using a model for the time-dependent meta-galactic radiation field consistent with currently available far-infrared to optical data, the cascade contributions by faint, unresolved sources like blazars and FRI galaxies have been calculated. We come to the conclusion that depending on what is known so far about AGN, they are not able to produce the total extragalactic flux detected by EGRET. A test for the model will be the upcoming observations with FERMI. It would also be helpful to detect a signal above 100 GeV where the gamma-ray flux declines to 10^-7GeV sr^-1 cm^-2 s^-1.

Original language	English
Pages (from-to)	510-513
Number of pages	4
Journal	AIP Conference Proceedings
Volume	1085
DOIs	https://doi.org/10.1063/1.3076721
Publication status	Published - 2009
Externally published	Yes
Event	4th International Meeting on High Energy Gamma-Ray Astronomy - Heidelberg, Germany Duration: 2008 Jul 7 → 2008 Jul 11

Keywords

Background radiations
Gamma-ray sources

ASJC Scopus subject areas

Physics and Astronomy(all)

Access to Document

10.1063/1.3076721

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@article{05623982274847f0a4d408cfbfdf9cc0,

title = "Can the extragalactic gamma-ray background be explained by AGN?",

abstract = "Very high energy gamma-rays from blazars traversing cosmological distances through the meta-galactic radiation field can convert into electron-positron pairs in photon-photon collisions. The converted gamma-rays initiate electromagnetic cascades driven by inverse-Compton scattering with microwave background photons. Using a model for the time-dependent meta-galactic radiation field consistent with currently available far-infrared to optical data, the cascade contributions by faint, unresolved sources like blazars and FRI galaxies have been calculated. We come to the conclusion that depending on what is known so far about AGN, they are not able to produce the total extragalactic flux detected by EGRET. A test for the model will be the upcoming observations with FERMI. It would also be helpful to detect a signal above 100 GeV where the gamma-ray flux declines to 10-7GeV sr-1 cm-2 s-1.",

keywords = "Background radiations, Gamma-ray sources",

author = "Kneiske, {Tanja M.} and Karl Mannheim and Lukasz Stawarz and Jun Kataoka",

year = "2009",

doi = "10.1063/1.3076721",

language = "English",

volume = "1085",

pages = "510--513",

journal = "AIP Conference Proceedings",

issn = "0094-243X",

publisher = "American Institute of Physics Publising LLC",

note = "4th International Meeting on High Energy Gamma-Ray Astronomy ; Conference date: 07-07-2008 Through 11-07-2008",