2009/04/22 by F. Aharonian, A. G. Akhperjanian, G. Anton +97
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Fermi Gamma-ray Space Telescope #Flux (metallurgy) #Galactic plane #Gamma-ray bursts and supernovae #Nuclear physics #Optics #Photon #Physics #Pulsar #Radiation #Spectral index #Spectral line #Stars #astro-ph.HE
paper · pdf · doi:10.1051/0004-6361/200811357
Accepted for publication on Astron. Astrophys
arxiv created 2009/04/22 · openalex publication_date 2009/04/29 · arxiv updated 2015/05/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
<i>Aims. <i/>Detection of a <i>γ<i/>-ray source above 300 GeV is reported, confirming the unidentified source MGRO J1908+06, discovered by the Milagro collaboration at a median energy of 20 TeV.<i>Methods. <i/>The source was observed during 27 h as part of the extension of the HESS Galactic plane survey to longitudes >30°. <i>Results. <i/>HESS J1908+063 is detected at a significance level of 10.9<i>σ<i/> with an integral flux above 1 TeV of (3.76 <i>±<i/> <i>±<i/> )10<sup>-12<sup/> ph cm<sup>-2<sup/> s<sup>-1<sup/>, and a spectral photon index <i>Γ<i/> = 2.10<i>±<i/><i>±<i/> 0.2. The positions and fluxes of HESS J1908+063 and MGRO J1908+06 are in good agreement. Possible counterparts at other wavelengths and the origin of the <i>γ<i/>-ray emission are discussed. The nearby unidentified GeV source, GRO J1908+0556 (GeV) which also remains unidentified and the new Fermi pulsar 0FGL J1907.5+0617, may be connected to the TeV source.