On the variability of quasars: A link between the Eddington ratio and optical variability?

Brian C. Wilhite, Robert J. Brunner, Catherine J. Grier, Donald P. Schneider, Daniel E. Vanden Berk

Research output: Contribution to journalArticle

74 Scopus citations

Abstract

Repeat scans by the Sloan Digital Sky Survey (SDSS) of a 278-deg 2 stripe along the celestial equator have yielded an average of over 10 observations each for nearly 8000 spectroscopically confirmed quasars. Over 2500 of these quasars are in the redshift range such that the C iv λ 1549 emission line is visible in the SDSS spectrum. Utilizing the width of these C iv lines and the luminosity of the nearby continuum, we estimate black hole masses for these objects. In an effort to isolate the effects of black hole mass and luminosity on the photometric variability of our data set, we create several subsamples by binning in these two physical parameters. By comparing the ensemble structure functions of the quasars in these bins, we are able to reproduce the well-known anticorrelation between luminosity and variability, now showing that this anticorrelation is independent of the black hole mass. In addition, we find a correlation between variability and the mass of the central black hole. By combining these two relations, we identify the Eddington ratio as a possible driver of quasar variability, most likely due to differences in accretion efficiency.

Original languageEnglish (US)
Pages (from-to)1232-1240
Number of pages9
JournalMonthly Notices of the Royal Astronomical Society
Volume383
Issue number3
DOIs
StatePublished - Jan 1 2008

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Fingerprint Dive into the research topics of 'On the variability of quasars: A link between the Eddington ratio and optical variability?'. Together they form a unique fingerprint.

  • Cite this