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

Domínguez, A.; Sánchez-Conde, M. A.; Prada, F.
Referencia bibliográfica

Journal of Cosmology and Astroparticle Physics, Issue 11, pp. 020 (2011).

Fecha de publicación:
11
2011
Número de autores
3
Número de autores del IAC
1
Número de citas
60
Número de citas referidas
51
Descripción
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.