Dwarf AGNs from variability for the origins of seeds (DAVOS): optical variability of broad-line dwarf AGNs from the zwicky transient facility. Issue 1 (16th February 2023)

• Record Type: Journal Article
• Authors: Wang, Z Franklin; Burke, Colin J; Liu, Xin; Shen, Yue
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 521:Issue 1(2023)
• Page Start: 99
• Page End: 113
• Publication Date: 2023-02-16
• Subjects: accretion, accretion discs -- black hole physics -- galaxies: active -- galaxies: dwarf; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stad532
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: We study the optical variability of a sample of candidate low-mass (dwarf and Seyfert) active galactic nuclei (AGNs) using Zwicky Transient Facility g -band light curves. Our sample is compiled from broad-line AGNs in dwarf galaxies reported in the literature with single-epoch virial black hole (BH) masses in the range M BH ∼ 10 4 –10 8 M⊙ . We measure the characteristic 'damping' time-scale of the optical variability τDRW, beyond which the power spectral density flattens, of a final sample of 79 candidate low-mass AGNs with high-quality light curves. Our results provide further confirmation of the M BH –τDRW relation from previous work within 1σ agreement, adding 78 new low-mass AGNs to the relation. The agreement suggests that the virial BH mass estimates for these AGNs are generally reasonable. We expect that the optical light curve of an accreting intermediate-mass black hole (IMBH) to vary with a rest-frame damping time-scale of ∼tens of hours, which could enable detection and direct mass estimation of accreting IMBHs in wide-field time-domain imaging surveys with sufficient cadence like with the Vera C. Rubin Observatory.