Steps toward Determination of the Size and Structure of the Broad‐Line Region in Active Galactic Nuclei. XII. Ground‐based Monitoring of 3C 390.3

Abstract

Resultsof a ground-based optical monitoring campaign on 3C 390.3 in 1994-95 are presented. The broad-band fluxes (B, V , R, and I), the spectrophotometric optical continuum flux F λ (5177Å), and the integrated emission-line fluxes of Hα, Hβ, Hγ, He i λ5876, and He ii λ4686 all show a nearly monotonic increase with episodes of milder short-term variations superposed. The amplitude of the continuum variations increases with decreasing wavelength (4400 -9000Å). The optical continuum variations follow the variations in the ultraviolet and X-ray with time delays, measured from the centroids of the cross-correlation functions, typically around 5 days, but with uncertainties also typically around 5 days; zero time delay between the high-energy and low-energy continuum variations cannot be ruled out. The strong optical emission lines Hα , Hβ , Hγ , and He i λ5876 respond to the high-energy continuum variations with time delays typically about 20 days, with uncertainties of about 8 days. Thereis some evidence that He ii λ4686 responds somewhat more rapidly, with a time delay of around 10 days, but again, the uncertainties are quite large (∼ 8 days).The mean and rms spectra of the Hα and Hβ line profiles provide indications for the existence of at least three distinct components located at ±4000 and 0 km s −1 relative to the line peak. The emission-line profile variations are largest near line center.

Supermassive Black Holes With High Accretion Rates in Active Galactic Nuclei. V. A New Size–luminosity Scaling Relation for the Broad-Line Region

“…The reverberation is delayed because of the difference in light travel between Hβ and ionizing photons and is thus expected to deliver information on the kinematics and structure of the BLR. The unambiguous reverberation of the lines, detected by monitoring campaigns from ultraviolet to optical bands since the late 1980s, supports this picture of the central engine of active galactic nuclei (AGNs) (e.g., Clavel et al 1991;Maoz et al 1991;Peterson et al 1991;Peterson 1993;Dietrich et al 1993Dietrich et al , 1998Dietrich et al , 2012Wanders et al 1993;Kaspi et al 2000;Denney et al 2006Denney et al , 2010Bentz et al 2009Bentz et al , 2014Grier et al 2012; Papers I-IV; Barth et al 2013Barth et al , 2015Shen et al 2015Shen et al , 2016. The b R H -L 5100 relation was first discussed by Koratkar & Gaskell (1991) and Peterson (1993).…”

A high fraction of double-peaked narrow emission lines in powerful active galactic nuclei

“…Figure 6 shows that the relation between V max off and [O iii] luminosity seems to be consistent with the theoretical curve as expected for radiation-pressure driven outflows with V max off ∝ L 1/4 (e.g., Laor & Brandt 2002), except for a possible turnover at the high luminosity end (i.e., dotted line in Figure 6). This general agreement is somewhat surprising, because the theoretical relation is expected for outflows associated with AGN broad-line regions whose sizes are at least two orders of magnitude smaller than that of the narrow-line regions being probed by the observed [O iii] emission (e.g., Dietrich et al 1998;Peterson et al 2004). In addition, there is a significant scatter 8 in the correlation between [O iii] luminosity and the AGN bolometric luminosity (e.g., Heckman et al 2004;Reyes et al 2008;Shen et al 2011a).…”

An improved test of the binary black hole hypothesis for quasars with double-peaked broad Balmer lines

“…Additional constraints on the orbital inclination angle through additional radio observations will help improve the mass limits from the radial velocity curves. Other tests involving UV spectroscopy (see Eracleous et al 2009) and reverberation mapping (see Dietrich et al 1998) will also be helpful.…”

“…Thus, one should expect a corresponding time lag between the two peaks as they respond to changes in the continuum. However, Dietrich et al (1998) performed reverberation mapping studies on 3C 390.3 and report that the blue and the red peaks in the double-peaked line profiles vary simultaneously within 3 days. Similarly, Sergeev et al (2000) and more recently Shapovalova et al (2013) who performed reverberation mapping studies on Arp 102B found no significant time lag between the two peaks.…”