THE LICK AGN MONITORING PROJECT 2011: SPECTROSCOPIC CAMPAIGN AND EMISSION-LINE LIGHT CURVES

In the Spring of 2011 we carried out a 2.5 month reverberation mapping\ncampaign using the 3 m Shane telescope at Lick Observatory, monitoring 15\nlow-redshift Seyfert 1 galaxies. This paper describes the observations,\nreductions and measurements, and data products from the spectroscopic campaign.\nThe reduced spectra were fitted with a multicomponent model in order to isolate\nthe contributions of various continuum and emission-line components. We present\nlight curves of broad emission lines and the AGN continuum, and measurements of\nthe broad H-beta line widths in mean and root-mean square (rms) spectra. For\nthe most highly variable AGNs we also measured broad H-beta line widths and\nvelocity centroids from the nightly spectra. In four AGNs exhibiting the\nhighest variability amplitudes, we detect anticorrelations between broad H-beta\nwidth and luminosity, demonstrating that the broad-line region "breathes" on\nshort timescales of days to weeks in response to continuum variations. We also\nfind that broad H-beta velocity centroids can undergo substantial changes in\nresponse to continuum variations; in NGC 4593 the broad H-beta velocity shifted\nby ~250 km/s over a one-month duration. This reverberation-induced velocity\nshift effect is likely to contribute a significant source of confusion noise to\nbinary black hole searches that use multi-epoch quasar spectroscopy to detect\nbinary orbital motion. We also present results from simulations that examine\nbiases that can occur in measurement of broad-line widths from rms spectra due\nto the contributions of continuum variations and photon-counting noise.\n