Quasar accretion disk sizes from continuum reverberation mapping in the DES standard-star fields

DES Collaboration, S. Avila, C. B. D'andrea, E. Gaztanaga, B. Hoyle, E. Macaulay, E. Swann

Research output: Contribution to journalArticlepeer-review

Abstract

Measurements of the physical properties of accretion disks in active galactic nuclei are important for better understanding the growth and evolution of supermassive black holes. We present the accretion disk sizes of 22 quasars from continuum reverberation mapping with data from the Dark Energy Survey (DES) standard-star fields and the supernova C fields. We construct continuum light curves with the griz photometry that span five seasons of DES observations. These data sample the time variability of the quasars with a cadence as short as 1 day, which corresponds to a rest-frame cadence that is a factor of a few higher than most previous work. We derive time lags between bands with both JAVELIN and the interpolated cross-correlation function method and fit for accretion disk sizes using the JAVELIN thin-disk model. These new measurements include disks around black holes with masses as small as ∼107 M o˙, which have equivalent sizes at 2500 Å as small as ∼0.1 lt-day in the rest frame. We find that most objects have accretion disk sizes consistent with the prediction of the standard thin-disk model when we take disk variability into account. We have also simulated the expected yield of accretion disk measurements under various observational scenarios for the Large Synoptic Survey Telescope Deep Drilling Fields. We find that the number of disk measurements would increase significantly if the default cadence is changed from 3 days to 2 days or 1 day.

Original languageEnglish
Article number16
Number of pages27
JournalAstrophysical Journal, Supplement Series
Volume246
Issue number1
DOIs
Publication statusPublished - 16 Jan 2020

Keywords

  • quasars
  • supermassive black holes
  • accretion
  • active galactic nuclei
  • reverberation mapping
  • UKRI
  • STFC

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