Search for Spectral Irregularities due to Photon–Axionlike-Particle Oscillations with the Fermi Large Area Telescope

Author/Creator ORCID

Date

2016-04-20

Department

Program

Citation of Original Publication

M. Ajello et al., Search for Spectral Irregularities due to Photon–Axionlike-Particle Oscillations with the Fermi Large Area Telescope, Phys. Rev. Lett. 116, 161101 (2016), DOI:https://doi.org/10.1103/PhysRevLett.116.161101

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This work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law

Subjects

Abstract

We report on the search for spectral irregularities induced by oscillations between photons and axionlike-particles (ALPs) in the γ-ray spectrum of NGC 1275, the central galaxy of the Perseus cluster. Using 6 years of Fermi Large Area Telescope data, we find no evidence for ALPs and exclude couplings above 5×10⁻¹² GeV⁻¹ for ALP masses 0.5≲ma≲5 neV at 95% confidence. The limits are competitive with the sensitivity of planned laboratory experiments, and, together with other bounds, strongly constrain the possibility that ALPs can reduce the γ-ray opacity of the Universe.