2010ApJ...722L..39A -
Astrophys. J., 722, L39-L44 (2010/October-2)
Evidence for gamma-ray halos around active galactic nuclei and the first measurement of intergalactic magnetic fields.
ANDO S. and KUSENKO A.
Abstract (from CDS):
Intergalactic magnetic fields (IGMFs) can cause the appearance of halos around the gamma-ray images of distant objects because an electromagnetic cascade initiated by a high-energy gamma-ray interaction with the photon background is broadened by magnetic deflections. We report evidence of such gamma-ray halos in the stacked images of the 170 brightest active galactic nuclei (AGNs) in the 11 month source catalog of the Fermi Gamma-Ray Space Telescope. Excess over the point-spread function in the surface brightness profile is statistically significant at 3.5σ (99.95% confidence level), for the nearby, hard population of AGNs. The halo size and brightness are consistent with IGMF, BIGMF≈ 10–15 G. The knowledge of IGMF will facilitate the future gamma-ray and charged-particle astronomy. Furthermore, since IGMFs are likely to originate from the primordial seed fields created shortly after the big bang, this potentially opens a new window on the origin of cosmological magnetic fields, inflation, and the phase transitions in the early universe.
Abstract Copyright:
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Journal keyword(s):
galaxies: active - gamma rays: general - ISM: magnetic fields
Simbad objects:
4
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