Taking a Long Look: A Two-decade Reverberation Mapping Study of High-luminosity Quasars

Shai Kaspi, W. N. Brandt, Dan Maoz, Hagai Netzer, Donald P. Schneider, Ohad Shemmer, C. J. Grier

Research output: Contribution to journalArticlepeer-review

3 Scopus citations

Abstract

Reverberation mapping (RM) of active galactic nuclei (AGNs) has been used over the past three decades to determine AGN broad-line region (BLR) sizes and central black hole masses, and their relations with the AGN luminosity. Until recently, the sample of objects with RM data was limited to low-luminosity AGNs (L opt ≲ 1046 erg s-1) and low redshifts (z ≲ 0.5). Here we present results from an RM project of some of the most luminous and highest-redshift quasars that have been mapped to date. The study is based on almost 20 years of photometric monitoring of 11 quasars, 6 of which were monitored spectrophotometrically for 13 yr. This is the longest RM project carried out so far on this type of AGNs. We successfully measure a time lag between the C iv λ 1549 broad emission line and the quasar continuum in three objects, and measure a C iii] λ 1909 lag in one quasar. Together with recently published data on C iv RM, the BLR size is found to scale as the square root of the UV luminosity over eight orders of magnitude in AGN luminosity. There is a significant scatter in the relation, part of which may be intrinsic to the AGNs. Although the C iv line is probably less well suited than Balmer lines for determination of the mass of the black hole, virial masses are tentatively computed, and in spite of a large scatter, we find that the mass of the black hole scales as the square root of the UV luminosity.

Original languageEnglish (US)
Article number129
JournalAstrophysical Journal
Volume915
Issue number2
DOIs
StatePublished - Jul 10 2021
Externally publishedYes

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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