We present models of the Hβ-emitting broad-line region (BLR) in seven Seyfert 1 galaxies from the Lick AGN (Active Galactic Nucleus) Monitoring Project 2011 sample, drawing inferences on the BLR structure and dynamics as well as the mass of the central supermassive black hole. We find that the BLR is generally a thick disk, viewed close to face-on, with preferential emission back toward the ionizing source. The dynamics in our sample range from near-circular elliptical orbits to inflowing or outflowing trajectories. We measure black hole masses of log 10 (M BH /M ) = 6.48 +0.21 −0.18 for PG 1310−108, 7.50 +0.25 −0.18 for Mrk 50, 7.46 +0.15 −0.21 for Mrk 141, 7.58 +0.08 −0.08 for Mrk 279, 7.11 +0.20 −0.17 for Mrk 1511, 6.65 +0.27 −0.15 for NGC 4593, and 6.94 +0.14 −0.14 for Zw 229−015.We use these black hole mass measurements along with cross-correlation time lags and line widths to recover the scale factor f used in traditional reverberation mapping measurements. Combining our results with other studies that use this modeling technique, bringing our sample size to 16, we calculate a scale factor that can be used for measuring black hole masses in other reverberation mapping campaigns. When using the root-mean-square (rms) spectrum and using the line dispersion to measure the line width, we find log 10 (f rms,σ ) pred = 0.57 ± 0.19. Finally, we search for correlations between f and other AGN and BLR parameters and find marginal evidence that f is correlated with M BH and the BLR inclination angle, but no significant evidence of a correlation with the AGN luminosity or Eddington ratio.
In a series of papers, we aim at stepping towards characterizing physical properties of the AGN dust torus by combining IR highspatial resolution observations with 3D clumpy torus models. In this first paper, we present mid-IR imaging and 8−13 μm lowresolution spectroscopy of nine type 1 and ten type 2 AGN. The observations were carried out with the VLT/VISIR mid-IR imager and spectrograph and can be considered the largest currently available mid-infrared spectro-photometric data set of AGN at spatial resolution < ∼ 100 pc. These data resolve scales at which the emission from the dust torus dominates the overall flux, and emission from the host galaxy (e.g. star-formation) is resolved out in most cases. The silicate absorption features are moderately deep and emission features, if seen at all, are shallow. The strongest silicate emission feature in our sample shows some notable shift of the central wavelength from the expected 9.7 μm (based on ISM extinction curves) to ∼10.5 μm. We compare the observed mid-IR luminosities of our objects to AGN luminosity tracers (X-ray, optical and [O iii] luminosities) and find that the mid-IR radiation is emitted quite isotropically. In two cases, IC 5063 and MCG-3-34-64, we find evidence for extended dust emission in the narrow-line region. We confirm the correlation between observed silicate feature strength and Hydrogen column density, which was recently found in Spitzer data at lower spatial resolution. In a further step, our 3D clumpy torus model has been used to interpret the data. We show that the strength of the silicate feature and the mid-IR spectral index α can be used to get reasonable constraints on the radial dust distribution of the torus and the average number of clouds N 0 along an equatorial line-of-sight in clumpy torus models. The mid-IR spectral index α is almost exclusively determined by the radial dust distribution power-law index a, while the silicate feature depth mostly depends on N 0 and the torus inclination. A comparison of model predictions to our type 1 and type 2 AGN reveals that average parameters of a = −1.0 ± 0.5 and N 0 = 5 − 8 are typically seen in the presented sample, which means that the radial dust distribution is rather shallow. As a proof-of-concept of this method, we compared the model parameters derived from α and the silicate feature strength to more detailed studies of full IR SEDs and interferometry and found that the constraints on a and N 0 are consistent. Finally, we may have found evidence that the radial structure of the torus changes from low to high AGN luminosities towards steeper dust distributions, and we discuss implications for the IR size-luminosity relation.
The time delay between flux variations in different wavelength bands can be used to probe the inner regions of active galactic nuclei (AGN). Here, we present the first measurements of the time delay between optical and near-infrared (NIR) flux variations in H0507+164, a nearby Seyfert 1.5 galaxy at z = 0.018. The observations in the optical V-band and NIR J, H and K s bands carried over 35 epochs during the period October 2016 to April 2017 were used to estimate the inner radius of the dusty torus. From a careful reduction and analysis of the data using crosscorrelation techniques, we found delayed responses of the J, H and K s light curves to the V-band light curve. In the rest frame of the source, the lags between optical and NIR bands are found to be 27.1 +13.5 −12.0 days (V vs. J), 30.4 +13.9 −12.0 days (V vs. H) and 34.6 +12.1 −9.6 days (V vs. K s). The lags between the optical and different NIR bands are thus consistent with each other. The measured lags indicate that the inner edge of dust torus is located at a distance of 0.029 pc from the central UV/optical AGN continuum. This is larger than the radius of the broad line region of this object determined from spectroscopic monitoring observations thereby supporting the unification model of AGN. The location of H0507+164 in the τ-M V plane indicates that our results are in excellent agreement with the now known lag-luminosity scaling relationship for dust in AGN.
We present the color and flux variability analysis at 3.4 µm (W 1-band) and 4.6 µm (W 2-band) of 492 narrow-line Seyfert 1 (NLSy1) galaxies using archival data from the Wide-field Infrared Survey Explorer (WISE). In the WISE color-color, (W 1 − W 2) versus (W 2 − W 3) diagram, ∼ 58% of the NLSy1 galaxies of our sample lie in the region occupied by the blazar category of active galactic nuclei (AGN). The mean W 1 − W 2 color of candidate variable NLSy1 galaxies is 0.99 ± 0.18 mag. The average amplitude of variability is 0.11 ± 0.07 mag in long-term (multi-year) with no difference in variability between W 1 and W 2-bands. The W 1 − W 2 color of NLSy1 galaxies is anti-correlated with the relative strength of [O III] to Hβ, strongly correlated with continuum luminosity, black hole mass, and Eddington ratio. The long-term amplitude of variability shows weak anti-correlation with the Fe II strength, continuum luminosity and Eddington ratio. A positive correlation between color as well as the amplitude of variability with the radio power at 1.4 GHz was found for the radio-detected NLSy1 galaxies. This suggests non-thermal synchrotron contribution to the mid-infrared color and flux variability in radio-detected NLSy1 galaxies.
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