Change search
ReferencesLink to record
Permanent link

Direct link
Resolving the Extragalactic gamma-Ray Background above 50 GeV with the Fermi Large Area Telescope
Show others and affiliations
Number of Authors: 129
2016 (English)In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 116, no 15Article in journal (Refereed) Published
Abstract [en]

The Fermi Large Area Telescope (LAT) Collaboration has recently released a catalog of 360 sources detected above 50 GeV (2FHL). This catalog was obtained using 80 months of data re-processed with Pass 8, the newest event-level analysis, which significantly improves the acceptance and angular resolution of the instrument. Most of the 2FHL sources at high Galactic latitude are blazars. Using detailed Monte Carlo simulations, we measure, for the first time, the source count distribution, dN= dS, of extragalactic.-ray sources at E > 50 GeV and find that it is compatible with a Euclidean distribution down to the lowest measured source flux in the 2FHL (8 x 10(-12) ph cm(-2) s(-1)). We employ a one-point photon fluctuation analysis to constrain the behavior of dN= dS below the source detection threshold. Overall, the source count distribution is constrained over three decades in flux and found compatible with a broken power law with a break flux, Sb, in the range [8 x 10-12; 1.5 x 10-11] ph cm(-2) s(-1) and power-law indices below and above the break of a 2. [1.60; 1.75] and a 1 +/- 2.49 +/- 0.12, respectively. Integration of dN= dS shows that point sources account for at least 86_16 -14 % of the total extragalactic gamma-ray background. The simple form of the derived source count distribution is consistent with a single population (i. e., blazars) dominating the source counts to the minimum flux explored by this analysis. We estimate the density of sources detectable in blind surveys that will be performed in the coming years by the Cherenkov Telescope Array.

Place, publisher, year, edition, pages
2016. Vol. 116, no 15
National Category
Physical Sciences
Identifiers
URN: urn:nbn:se:su:diva-130165DOI: 10.1103/PhysRevLett.116.151105ISI: 000373984100003OAI: oai:DiVA.org:su-130165DiVA: diva2:927458
Available from: 2016-05-12 Created: 2016-05-09 Last updated: 2016-05-12Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text
By organisation
Department of PhysicsThe Oskar Klein Centre for Cosmo Particle Physics (OKC)
In the same journal
Physical Review Letters
Physical Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 34 hits
ReferencesLink to record
Permanent link

Direct link