2005/07/31 by Ł. Stawarz, L. Stawarz, T. M. Kneiske +2 · 3 citations
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #Compton scattering #Egret #Electron #Galactic astronomy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gamma ray #Magnetic field #Milky Way #Optics #Photon #Physics #Radio Astronomy Observations and Technology #Radio galaxy #Synchrotron radiation #astro-ph
paper · pdf · doi:10.1086/498084
published as Astrophys.J.637:693-698,2006 · 18 pages, 3 figures included. ApJ accepted
arxiv created 2005/09/14 · openalex publication_date 2006/01/25 · openalex created_date 2016/06/24 · arxiv updated 2016/08/30 · openalex updated_date 2026/08/05
We discuss the contribution of kiloparsec-scale jets in FR I radio galaxies to the diffuse γ-ray background radiation. The analyzed γ-ray emission comes from inverse-Compton scattering of starlight photon fields by the ultrarelativistic electrons whose synchrotron radiation is detected from such sources at radio, optical, and X-ray energies. We find that these objects, under the minimum-power hypothesis (corresponding to a magnetic field of 300 μG in the brightest knots of these jets), can contribute about one percent to the extragalactic γ-ray background measured by EGRET. We point out that this result already indicates that the magnetic fields in kiloparsec-scale jets of low-power radio galaxies are not likely to be smaller than 10 μG on average, as otherwise the extragalactic γ-ray background would be overproduced.