Observational window effects on multi-object Reverberation Mapping
  Contemporary reverberation mapping campaigns are employing wide-area
photometric data and high-multiplex spectroscopy to efficiently monitor
hundreds of active galactic nuclei (AGN). However, the interaction of the
window function(s) imposed by the observation cadence with the reverberation
lag and AGN variability time scales (intrinsic to each source over a range of
luminosities) impact our ability to recover these fundamental physical
properties. Time dilation effects due to the sample source redshift
distribution introduces added complexity. We present comprehensive analysis of
the implications of observational cadence, seasonal gaps and campaign baseline
duration (i.e., the survey window function) for reverberation lag recovery. We
find the presence of a significant seasonal gap dominates the efficacy of any
given campaign strategy for lag recovery across the parameter space,
particularly for those sources with lags above $\sim$100 days in the
observed-frame. Using the OzDES survey as a baseline, we consider the
implications of this analysis for the 4MOST/TiDES campaign providing concurrent
follow-up of the LSST deep-drilling fields, as well as upcoming programs. We
conclude the success of such surveys will be critically limited by the seasonal
visibility of some potential field choices, but show significant improvement
from extending the baseline. Optimising the sample selection to fit the window
function will improve survey efficacy.
