Sensitivity of the Chrenkov Telescope Array to the detection of axion-llike particles at high gamma-ray opacieties
2014 (English)In: Journal of Cosmology and Astroparticle Physics, ISSN 1475-7516, no 12, 016- p.Article in journal (Refereed) Published
Extensions of the Standard Model of particles commonly predict the existence of axion(-like) particles (ALPs) that could be detected through their coupling to photons in external magnetic fields. This coupling could lead to modifications of gamma-ray spectra from extragalactic sources. Above a certain energy, the gamma-ray flux should be exponentially damped due to the interaction with photons of background radiations fields. ALPs, on the other hand, propagate unimpeded over cosmological distances and a reconversion into gamma-rays could lead to an additional component in the spectra. Here, we present the sensitivity of the proposed Cherenkov Telescope Array (CTA) to detect this spectral hardening. Using the full instrumental response functions of CTA, a combined likelihood analysis of four gamma-ray sources shows that a significant detection of the ALP signal is possible for couplings g(a gamma) greater than or similar to 2 x 10(-11) GeV-1 and ALP masses m(a) less than or similar to 100 neV. We discuss the dependency of these values on different model assumptions and magnetic-field scenarios and identify the best observation strategy to search for an ALP induced boost of the gamma-ray flux.
Place, publisher, year, edition, pages
2014. no 12, 016- p.
gamma ray experiments, active galactic nuclei, magnetic fields, galaxy clusters
Astronomy, Astrophysics and Cosmology
IdentifiersURN: urn:nbn:se:su:diva-112933DOI: 10.1088/1475-7516/2014/12/016ISI: 000346298800016OAI: oai:DiVA.org:su-112933DiVA: diva2:782150