THE lick AGN monitoring project 2011: Spectroscopic campaign and emission-line light curves

Aaron J. Barth, Vardha N. Bennert, Gabriela Canalizo, Alexei V. Filippenko, Elinor L. Gates, Jenny E. Greene, Weidong Li, Matthew A. Malkan, Anna Pancoast, David J. Sand, Daniel Stern, Tommaso Treu, Jong Hak Woo, Roberto J. Assef, Hyun Jin Bae, Brendon J. Brewer, S. Bradley Cenko, Kelsey I. Clubb, Michael C. Cooper, Aleksandar M. Diamond-StanicKyle D. Hiner, Sebastian F. Honig, Eric Hsiao, Michael T. Kandrashoff, Mariana S. Lazarova, A. M. Nierenberg, Jacob Rex, Jeffrey M. Silverman, Erik J. Tollerud, Jonelle L. Walsh

Research output: Contribution to journalArticlepeer-review

148 Scopus citations


In the Spring of 2011 we carried out a 2.5 month reverberation mapping campaign using the 3 m Shane telescope at Lick Observatory, monitoring 15 low-redshift Seyfert 1 galaxies. This paper describes the observations, reductions and measurements, and data products from the spectroscopic campaign. The reduced spectra were fitted with a multicomponent model in order to isolate the contributions of various continuum and emission-line components. We present light curves of broad emission lines and the active galactic nucleus (AGN) continuum, and measurements of the broad Hβ line widths in mean and rms spectra. For the most highly variable AGNs we also measured broad Hβ line widths and velocity centroids from the nightly spectra. In four AGNs exhibiting the highest variability amplitudes, we detect anticorrelations between broad Hβ width and luminosity, demonstrating that the broad-line region "breathes" on short timescales of days to weeks in response to continuum variations. We also find that broad Hβ velocity centroids can undergo substantial changes in response to continuum variations; in NGC 4593, the broad Hβ velocity shifted by ∼250 km s-1 over a 1 month period. This reverberation-induced velocity shift effect is likely to contribute a significant source of confusion noise to binary black hole searches that use multi-epoch quasar spectroscopy to detect binary orbital motion. We also present results from simulations that examine biases that can occur in measurement of broad-line widths from rms spectra due to the contributions of continuum variations and photon-counting noise.

Original languageEnglish (US)
Article number26
JournalAstrophysical Journal, Supplement Series
Issue number2
StatePublished - Apr 1 2015

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


  • galaxies: Seyfert
  • galaxies: active
  • galaxies: nuclei
  • techniques: spectroscopic


Dive into the research topics of 'THE lick AGN monitoring project 2011: Spectroscopic campaign and emission-line light curves'. Together they form a unique fingerprint.

Cite this