Abstract
ABSTRACT We present the first intensive continuum reverberation mapping study of the high accretion-rate Seyfert galaxy Mrk 110. The source was monitored almost daily for more than 200 d with the Swift X-ray and ultraviolet (UV)/optical telescopes, supported by ground-based observations from Las Cumbres Observatory, the Liverpool Telescope, and the Zowada Observatory, thus extending the wavelength coverage to 9100 Å. Mrk 110 was found to be significantly variable at all wavebands. Analysis of the intraband lags reveals two different behaviours, depending on the time-scale. On time-scales shorter than 10 d the lags, relative to the shortest UV waveband (∼1928 Å), increase with increasing wavelength up to a maximum of ∼2 d lag for the longest waveband (∼9100 Å), consistent with the expectation from disc reverberation. On longer time-scales, however, the g-band lags the Swift BAT hard X-rays by ∼10 d, with the z-band lagging the g-band by a similar amount, which cannot be explained in terms of simple reprocessing from the accretion disc. We interpret this result as an interplay between the emission from the accretion disc and diffuse continuum radiation from the broad-line region.
Highlights
Despite decades of observations across almost all of the accessible electromagnetic spectrum, and their impact in galaxy evolution (e.g. Ferrarese & Merritt 2000; Gebhardt et al 2000; Marconi et al 2004), many aspects of active galactic nuclei (AGNs) are still poorly understood
Most of the AGN luminosity is released as thermal radiation from an optically thick, geometrically thin accretion disc that dominates the ultraviolet (UV), and a non-thermal power-law that dominates the hard X-rays and which arises from the Compton up-scattering of lower energy seed photons
Filtering the data on long (>10 d) and short (
Summary
Despite decades of observations across almost all of the accessible electromagnetic spectrum, and their impact in galaxy evolution (e.g. Ferrarese & Merritt 2000; Gebhardt et al 2000; Marconi et al 2004), many aspects of active galactic nuclei (AGNs) are still poorly understood. The few studies to date on higher accretion-rate objects (Cackett et al 2020; Pahari et al 2020) still reported discrepancies between the observed and predicted lags similar to those of lower accretion-rate AGNs. Among the various classes of AGN, narrow-line Seyfert 1 (NLS1) galaxies (i.e. active galaxies with optical emission lines width at half-maximum, FWHM ≈82 000 km s−1, weak [O III], and a strong Fe II/H β ratio; Osterbrock & Pogge 1985; Mathur 2000) and are probably one of the most suited for this investigation.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
