Mon. Not. R. Astron. Soc., 485, 2001-2009 (2019/May-2)
Non-thermal emission in the lobes of Fornax A.
PERSIC M. and REPHAELI Y.
Abstract (from CDS):
Current measurements of the spectral energy distribution in radio, X-ray and γ-ray provide a sufficiently wide basis for determining basic properties of energetic electrons and protons in the extended lobes of the radio galaxy Fornax A. Of particular interest is establishing observationally, for the first time, the level of contribution of energetic protons to the extended emission observed by the Fermi satellite. Two recent studies concluded that the observed γ-ray emission is unlikely to result from Compton scattering of energetic electrons off the optical radiation field in the lobes, and therefore that the emission originates from decays of neutral pions produced in interactions of energetic protons with protons in the lobe plasma, implying an uncomfortably high-proton energy density. However, our exact calculation of the emission by energetic electrons in the magnetized lobe plasma leads to the conclusion that all the observed emission can, in fact, be accounted for by energetic electrons scattering off the ambient optical radiation field, whose energy density (which, based on recent observations, is dominated by emission from the central galaxy NGC 1316) we calculate to be higher than previously estimated.
© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society
radiation mechanisms: non-thermal - galaxies: active - galaxies: individual: Fornax A - gamma rays: galaxies
erratum vol. 486, p. 950(2019)
View the reference in ADS
To bookmark this query, right click on this link: simbad:2019MNRAS.485.2001P and select 'bookmark this link' or equivalent in the popup menu