  The Telescope Array (TA) collaboration has reported a hotspot of 19
ultrahigh-energy cosmic rays (UHECRs). Using a universal model with one source
and energy-dependent magnetic deflections, we show that the distribution of the
TA hotspot events is consistent with a single source hypothesis, although
multiple sources cannot be ruled out. The chance probability of this
distribution arising from a homogeneous distribution is $0.2\%$. We describe a
Monte Carlo Bayesian (MCB) inference approach, which can be used to derive
parameters of the magnetic fields as well as the source coordinates, and we
apply this method to the TA hotspot data, inferring the location of the likely
source. We discuss possible applications of the same approach to future data.
