  The distribution of ultra-high-energy cosmic-ray arrival directions appears
to be nearly isotropic except for a dipole moment of order $6 \times
(E/10~\mathrm{EeV})$ per cent. Nonetheless, at the highest energies, as the
number of possible candidate sources within the propagation horizon and the
magnetic deflections both shrink, smaller-scale anisotropies might be expected
to emerge. On the other hand, the flux suppression reduces the statistics
available for searching for such anisotropies. In this work, we consider two
different lists of candidate sources: a sample of nearby starburst galaxies and
the 2MRS catalog tracing stellar mass within $250~\mathrm{Mpc}$. We combine
surface-detector data collected at the Pierre Auger Observatory until 2020 and
the Telescope Array until 2019, and use them to test models in which UHECRs
comprise an isotropic background and a foreground originating from the
candidate sources and randomly deflected by magnetic fields. The free
parameters of these models are the energy threshold, the signal fraction, and
the search angular scale. We find a correlation between the arrival directions
of $11.8\%_{-3.1\%}^{+5.0\%}$ of cosmic rays detected with $E \ge
38~\mathrm{EeV}$ by Auger or with $E \gtrsim 49~\mathrm{EeV}$ by TA and the
position of nearby starburst galaxies on a
${15.5^\circ}_{-3.2^\circ}^{+5.3^\circ}$ angular scale, with a $4.2\sigma$
post-trial significance, as well as a weaker correlation with the overall
galaxy distribution.
