Bibcode
Domínguez, A.; Sánchez-Conde, M. A.; Prada, F.
Bibliographical reference
Journal of Cosmology and Astroparticle Physics, Issue 11, pp. 020 (2011).
Advertised on:
11
2011
Citations
61
Refereed citations
52
Description
Discoveries of very high energy (VHE) photons from distant blazars
suggest that, after correction by extragalactic background light (EBL)
absorption, there is a flatness or even a turn-up in their spectra at
the highest energies that cannot be easily explained by the standard
framework. Here, it is shown that a possible solution to this problem is
achieved by assuming the existence of axion-like particles (ALPs) with
masses ~ 1 neV. The ALP scenario is tested making use of observations of
the highest redshift blazars known in the VHE energy regime, namely 3C
279, 3C 66A, PKS 1222+216 and PG 1553+113. In all cases, better fits to
the observed spectra are found when including ALPs rather than
considering EBL only. Interestingly, quite similar critical energies for
photon/ALP conversions are also derived, independently of the source
considered.