Axion-like particle imprint in cosmological very-high-energy sources

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
Number of authors
3
IAC number of authors
1
Citations
60
Refereed citations
51
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.
Type