Example of the elliptical uncertainty region around the neutrino event on August 12, 2015 (MJD 57246; shown with a black cross), and the positions of the three associations found for it in the OVRO sample. The gray solid lines mark the asymmetric statistical uncertainties in each direction (given in Table 1), multiplied by the factor of 1.3 discussed in the text. The solid black line shows the two-dimensional error ellipse when only statistical uncertainties are included. The gray dashed lines show the additional systematic uncertainty Δψ = 1.0° as found optimal for the mean flux density analysis in the CGRaBS sample, which is added in quadrature to the statistical uncertainties in all directions, and the blue dashed line marks the resulting two-dimensional error ellipse.