The Sloan Digital Sky Survey Reverberation Mapping Project: Sample Characterization

TL;DR

This paper provides a comprehensive characterization of 849 quasars from the SDSS-RM project, including spectral, absorption, and variability analyses, establishing a valuable benchmark for future reverberation mapping studies.

Contribution

It offers the first detailed spectral and variability characterization of a large, flux-limited quasar sample from SDSS-RM, with publicly available spectral fitting tools.

Findings

Diverse quasar properties covered across 0.1<z<4.5

Well-detected continuum and broad-line variability in many objects

Improved systemic redshift estimates for all quasars

Abstract

We present a detailed characterization of the 849 broad-line quasars from the Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) project. Our quasar sample covers a redshift range of 0.1<z<4.5 and is flux-limited to i_PSF<21.7 without any other cuts on quasar properties. The main sample characterization includes: 1) spectral measurements of the continuum and broad emission lines for individual objects from the coadded first-season spectroscopy in 2014; 2) identification of broad and narrow absorption lines in the spectra; 3) optical variability properties for continuum and broad lines from multi-epoch spectroscopy. We provide improved systemic redshift estimates for all quasars, and demonstrate the effects of signal-to-noise ratio on the spectral measurements. We compile measured properties for all 849 quasars along with supplemental multi-wavelength data for subsets of our sample from other surveys. The SDSS-RM sample probes a diverse range in quasar properties, and shows well detected continuum and broad-line variability for many objects from first-season monitoring data. The compiled properties serve as the benchmark for follow-up work based on SDSS-RM data. The spectral fitting tools are made public along with this work.