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

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.