The correlation between the optical/UV count rates from the 6 OM filters and the EPIC-pn X-ray count rate for the 10 XMM-Newton observations at energies from 0.3 keV to 10 keV. Black asterisks: V (5430 Å) filter, black diamonds: B (4500 Å), orange triangles: U (3440 Å), filled green circles: UVW1 (2910 Å), unfilled red circles: UVM2 (2310 Å), blue squares: UVW2 (2120Å). The Pearson correlation coefficients are shown on the left y-axis and the associated null hypothesis probability p (i.e. probability of no correlation) from Student’s t-test on the right y-axis. The dashed black line indicates p at 5%, which shows that below ~1 keV the correlation is statistically significant at 95% confidence.