Stacked reverberation lags at high redshift

Abstract

Over the past 20years reverberation mapping has proved one of the most successful techniques for studying the local (<1pc) environment of super-massive black holes that drive active galactic nuclei. Key successes of reverberation mapping have been direct black hole mass estimates, the radius-luminosity relation for the Hbeta line and the calibration of single-epoch mass estimators commonly employed up to z~7. However, observing constraints mean that few studies have been successful at z>0.1, or for the more-luminous quasars that make up the majority of current spectroscopic samples, or for the rest-frame ultra-violet emission lines available in optical spectra of z>0.5 objects. Previously we described a technique for stacking cross correlations to obtain reverberation mapping results at high z. Here we present the first results from a campaign designed for this purpose. We construct stacked cross-correlation functions for the CIV and MgII lines and find a clear peak in both. We find the peak in the MgII correlation is at longer lags than CIV consistent with previous results at low redshift. For the CIV sample we are able to bin by luminosity and find evidence for increasing lags for more-luminous objects. This CIV radius-luminosity relation is consistent with previous studies but with a fraction of the observational cost.

5 pages, 5 figures, accepted for publication in MNRAS letters

References in corpus (3)

• The Radius-Luminosity Relationship for Active Galactic Nuclei: The Effect of Host-Galaxy Starlight on Luminosity Measurements
• Think Outside the Color Box: Probabilistic Target Selection and the SDSS-XDQSO Quasar Targeting Catalog
• First Results from Pan-STARRS1: Faint, High Proper Motion White Dwarfs in the Medium-Deep Fields

Cited by in corpus (8)

• A systematic search for close supermassive black hole binaries in the Catalina Real-Time Transient Survey
• The Sloan Digital Sky Survey Reverberation Mapping Project: Technical Overview
• Application of Stochastic Modeling to Analysis of Photometric Reverberation Mapping Data
• The Sloan Digital Sky Survey Reverberation Mapping Project: Composite Lags at $z\lesssim 1$
• Hierarchical Reverberation Mapping
• The Performance of Photometric Reverberation Mapping at High Redshift and the Reliability of Damped Random Walk Models
• OzDES Reverberation Mapping Program: Stacking analysis with H$\beta$, Mg II and C IV
• Mg II line properties in lobe-dominated quasars