1. Testing cosmology and fundamental physics with the Cherenkov Telescope ArrayH. Martínez-Huerta, Christopher Eckner, Gašper Kukec Mezek, Samo Stanič, Serguei Vorobiov, Lili Yang, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, published scientific conference contribution Abstract: The Cherenkov Telescope Array (CTA) is the next generation ground-based observatory for γ-ray astronomy at energies above 30 GeV. Thanks to its unique capabilities, CTA observations will
address a plethora of open questions in astrophysics, ranging from the origin of cosmic messengers to the exploration of the frontiers of physics. In this note, we present a comprehensive sensitivity study to assess the potential of CTA to measure the γ-ray absorption on the extragalactic background light (EBL), to constrain or detect intergalactic magnetic fields (IGMFs), and probe physics beyond the standard model such as axion-like particles (ALPs) and Lorentz invariance violation (LIV), which could modify the γ-ray spectra features expected from EBL absorption. Our results suggest that CTA will have unprecedented sensitivity to detect IGMF signatures and will probe so-far unexplored regions of the LIV and ALP parameter space. Furthermore, an indirect measurement of the EBL and of its evolution will be performed with unrivaled precision.
Keywords: very-high-energy gamma rays, the Cherenkov Telescope Array (CTA) Observatory, extragalactic background light (EBL), intergalactic magnetic fields (IGMFs), axion-like particles (ALPs), Lorentz invariance violation (LIV)
Published in RUNG: 07.11.2024; Views: 256; Downloads: 4
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2. Search for Axionlike-Particle-Induced Prompt γ -Ray Emission from Extragalactic Core-Collapse Supernovae with the Fermi Large Area TelescopeManuel Meyer, Tanja Petrushevska, 2020, original scientific article Abstract: During a core-collapse supernova (SN), axionlike particles (ALPs) could be produced through the Primakoff process and subsequently convert into γ rays in the magnetic field of the Milky Way. We do not find evidence for such a γ-ray burst in observations of extragalactic SNe with the Fermi Large Area Telescope (LAT). The SN explosion times are estimated from optical light curves and we find a probability of about ∼90% that the LAT observed at least one SN at the time of the core collapse. Under the assumption that at least one SN was contained within the LAT field of view, we exclude photon-ALP couplings ≳2.6×10−12 GeV−1 for ALP masses ma≲3×10−10 eV, improving previous limits from SN1987A by a factor of 2.
Keywords: darn matter, axions, axion-like particles, core-collapse supernovae
Published in RUNG: 15.06.2020; Views: 3488; Downloads: 83
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