Emission-Line and Continuum Reverberation Mapping of the NLS1 Galaxy WPVS 48

Abstract

WPVS 48 is a nearby narrow-line Seyfert 1 galaxy without previous analysis of the broad-line region (BLR) by means of optical spectroscopic reverberation mapping. By studying the continuum and emission line variability of WPVS 48, we aim to infer the BLR size as well as the mass of the central supermassive black hole (SMBH). We analyse data from a dedicated optical spectroscopic reverberation mapping campaign of WPVS 48 taken with the 10 m Southern African Large Telescope (SALT) at 24 epochs over a period of 7 months between December 2013 and June 2014. WPVS 48 shows variability throughout the campaign. We find a stratified BLR, where the variability amplitude of the integrated emission lines decreases with distance to the ionizing continuum source. Specifically, the variable emission of H$\alpha$, H$\beta$, H$\gamma$, He I $\lambda 5876$ originates at distances of $16.0_{-2.0}^{+4.0}$, $15.0_{-1.9}^{+4.5}$, $12.5_{-2.5}^{+3.5}$ and $14.0_{-2.1}^{+2.5}$ light-days, respectively, to the optical continuum at 5100 A. The He II $\lambda 4686$ lag is $\lesssim 5$ days. Based on the high S/N spectra, we identify variable emission of N III $\lambda 4640$ and C IV $\lambda 4658$ in the line complex with He II $\lambda 4686$. We derive interband continuum delays increasing with wavelength up to $\sim 8$ days. These delays are consistent with an additional diffuse continuum originating at the same distance as the variable Balmer emission. We derive a central black hole mass of $(1.3_{-0.6}^{+1.1})\times 10^7{M}_{\odot }$ based on the integrated line-widths and distances of the BLR and discuss corrections for the inclination angle. This gives an Eddington ratio $L/L_{\text{Edd}}\approx 0.39$ without correction for inclination.

22 pages, 17 figures

References in corpus (22)

• Space Telescope and Optical Reverberation Mapping Project. II. Swift and HST Reverberation Mapping of the Accretion Disk of NGC 5548
• Cold gas stripping in satellite galaxies: from pairs to clusters
• Reverberation mapping of Active Galactic Nuclei: from X-ray corona to dusty torus
• The characteristic blue spectra of accretion disks in quasars as uncovered in the infrared
• Space Telescope and Optical Reverberation Mapping Project. V. Optical Spectroscopic Campaign and Emission-Line Analysis for NGC 5548
• A Revised Broad-Line Region Radius and Black Hole Mass for the Narrow-Line Seyfert 1 NGC 4051
• The UV Continuum of Quasars: Models and SDSS Spectral Slopes
• A new class of flares from accreting supermassive black holes
• Intensive disc-reverberation mapping of Fairall 9: 1st year of Swift & LCO monitoring
• On the geometry of broad emission region in quasars
• On the multi-wavelength variability of Mrk 110: Two components acting at different timescales
• Spectral optical monitoring of 3C390.3 in 1995-2007: I. Light curves and flux variation of the continuum and broad lines
• The BH mass of nearby QSOs: a comparison of the bulge luminosity and virial methods
• Broad-line region structure and kinematics in the radio galaxy 3C 120
• A New Iron Emission Template for Active Galactic Nuclei. I. Optical Template for the H$\beta$ region
• AT 2021loi: A Bowen Fluorescence Flare with a Rebrightening Episode, Occurring in a Previously-Known AGN
• Fe II emission in active galactic nuclei
• The transient event in NGC 1566 from 2017 to 2019 -- I. An eccentric accretion disk and a turbulent, disk-dominated broad-line region unveiled by double-peaked Ca II and O I lines
• The Active Galactic Nuclei in the Hobby-Eberly Telescope Dark Energy Experiment Survey (HETDEX) I. Sample selection
• Reverberation Mapping of PG 0934+013 with the Southern African Large Telescope
• On the Performance of Quasar Reverberation Mapping in the Era of Time-Domain Photometric Surveys
• The Great Slump: Mrk926 reveals discrete and varying Balmer line satellite components during a drastic phase of decline