Tentative identification of the source of four UHECRs, and implications thereof

Abstract

Four UHECRs in the combined HiRes and AGASA datasets are backtracked in the Galactic magnetic field. They point to a common source which is localized to within 1 degree, if they are protons as is shown to be the most probable charge assignment. A Swift-BAT hard X-ray AGN in the galaxy CGCG 291-028 is the only notable source candidate within the source locus and within the GZK distance horizon. The spectrum of the four events is consistent with production in a transient event such as a stellar tidal disruption flare. Under the assumption the UHECRs were produced in CGCG 291-028, the total energy of UHECRs produced by the transient can be estimated and extragalactic magnetic deflections can be constrained. If CGCG 291-028 is indeed the source of the UHECRs, observations of its present state should elucidate the phenomenon of UHECR acceleration.