SDSS-RM project: MgII lags from 4yrs monitoring

We find significant time lags between the MgII and continuum lightcurves for 57 quasars, and define a "gold sample" of 24 quasars with the most reliable lag measurements.

We estimate false-positive rates for each lag that range from 1% to 24%, with an average false-positive rate of 11% for the full sample and 8% for the gold sample. There are an additional ~40 quasars with marginal MgII lag detections, which may yield reliable lags after additional years of monitoring. The MgII lags follow a radius-luminosity relation with a best-fit slope that is consistent with {alpha}=0.5, but with an intrinsic scatter of 0.36dex that is significantly larger than found for the H{beta} radius-luminosity relation.