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Ultra-high-energy-cosmic-ray hot spots from tidal disruption events

We consider the possibility that tidal disruption events (TDEs) caused by supermassive black holes (SMBHs) in nearby galaxies can account for the ultra-high-energy cosmic-ray (UHECR) hot spot reported recently by the Telescope Array (TA) and the warm spot by Pierre Auger Observatory (PAO). We describe the expected cosmic-ray signal from a TDE and derive the constraints set by the timescale for dispersion due to intergalactic magnetic fields and the accretion time of the SMBH. We demonstrate that TDEs in M82 can explain the hot spot detected by the TA. Based on data-driven assumptions regarding the SMBH mass function, the luminosity scaling of the TDEs and the mass dependence of their rate, we then analyze the full parameter space of the model to search for consistency with the full-sky isotropic signal. Doing so, we show that TDEs can account for both the TA hot spot and full-sky UHECR observations. Using our model we show that the warm spot in the PAO data in the direction of Centaurus A (Cen A) can also be explained by TDEs. Finally, we show that although both hydrogen and iron nuclei are viable candidates for UHECRs, iron nuclei require smaller intergalactic magnetic fields and are therefore more feasible if TDEs explain the TA and PAO results.

[arXiv:1512.04959]

18.12.2015
Daniel N. Pfeffer, Ely D. Kovetz, Marc Kamionkowski
ArXiv.org (Submitted on 15 Dec 2015)