Change search
ReferencesLink to record
Permanent link

Direct link
Show others and affiliations
2011 (English)In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 734, no 2, 116- p.Article in journal (Refereed) Published
Abstract [en]

We report the detection of high-energy gamma-rays from the quiescent Sun with the Large Area Telescope on board the Fermi Gamma-Ray Space Telescope (Fermi) during the first 18 months of the mission. These observations correspond to the recent period of low solar activity when the emission induced by cosmic rays (CRs) is brightest. For the first time, the high statistical significance of the observations allows clear separation of the two components: the point-like emission from the solar disk due to CR cascades in the solar atmosphere and extended emission from the inverse Compton (IC) scattering of CR electrons on solar photons in the heliosphere. The observed integral flux (>= 100 MeV) from the solar disk is (4.6 +/- 0.2inverted right perpendicularstatistical errorinverted left perpendicular(-0.08)(+1.0)inverted right perpendicularsystematic errorinverted left perpendicular) x 10(-7) cm(-2) s(-1), which is similar to 7 times higher than predicted by the nominal model of Seckel et al. In contrast, the observed integral flux (>= 100 MeV) of the extended emission from a region of 20 degrees radius centered on the Sun, but excluding the disk itself, (6.8 +/- 0.7[stat.](-0.4)(+0.5)[syst.]) x 10(-7) cm(-2) s(-1), along with the observed spectrum and the angular profile, is in good agreement with the theoretical predictions for the IC emission.

Place, publisher, year, edition, pages
2011. Vol. 734, no 2, 116- p.
Keyword [en]
astroparticle physics, cosmic rays, gamma rays: general, Sun: atmosphere, Sun: heliosphere, Sun: X-rays, gamma rays
National Category
Physical Sciences
URN: urn:nbn:se:su:diva-67590DOI: 10.1088/0004-637X/734/2/116ISI: 000291386500044OAI: diva2:470472
150Available from: 2011-12-29 Created: 2011-12-29 Last updated: 2012-07-04Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Conrad, JanYang, Zhaoyu
By organisation
Department of PhysicsThe Oskar Klein Centre for Cosmo Particle Physics (OKC)
In the same journal
Astrophysical Journal
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: 83 hits
ReferencesLink to record
Permanent link

Direct link