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Kim, Dohyeong,Im, Myungshin,Canalizo, Gabriela,Kim, Minjin,Kim, Ji Hoon,Woo, Jong-Hak,Taak, Yoon Chan,Kim, Jae-Woo,Lazarova, Mariana American Astronomical Society 2018 The Astrophysical journal Supplement series Vol.238 No.2
<P>We present medium-resolution spectra (R similar to 2000-4000) at 0.4-1.0 mu m and 0.7-2.5 mu m of 16 active galactic nuclei (AGNs) selected with red color in the near-infrared (NIR) of J - K > 2.0 mag at z similar to 0.3. We fit the H beta, H alpha, P beta, and P alpha lines from these spectra to obtain their luminosities and line widths. We derive the E(B - V) color excess values of the NIR-red AGNs using two methods, one based on the line-luminosity ratios and another based on the continuum slopes. The two E(B - V) values agree with each other at rms dispersion similar to 0.249. About half of the NIR-red AGNs have g' - K < 5 magnitude, and we find that these NIR-red, but blue in optical-NIR AGNs, have E(B - V) similar to 0, suggesting that a significant fraction of the NIR color-selected red AGNs are unobscured or only mildly obscured. After correcting for the dust extinction, we estimate the black hole (BH) masses and the bolometric luminosities of the NIR-red AGNs using the Paschen lines to calculate their Eddington ratios (lambda(Edd) ). The median Eddington ratios of nine NIR-red AGNs (log(lambda(Edd) ) similar or equal to -0.654 +/- 0.176) are only mildly higher than those of unobscured type 1 AGNs (log(lambda(Edd)) similar or equal to -0.961 +/- 0.008). Moreover, we find that the M-BH-sigma* relation for three NIR-red AGNs is consistent with that of unobscured type 1 AGNs at similar redshift. These results suggest that the NIR-red color selection alone is not effective at picking up dusty, intermediate-stage AGNs.</P>
THE LICK AGN MONITORING PROJECT 2011: SPECTROSCOPIC CAMPAIGN AND EMISSION-LINE LIGHT CURVES
Barth, Aaron J.,Bennert, Vardha N.,Canalizo, Gabriela,Filippenko, Alexei V.,Gates, Elinor L.,Greene, Jenny E.,Li, Weidong,Malkan, Matthew A.,Pancoast, Anna,Sand, David J.,Stern, Daniel,Treu, Tommaso,W IOP Publishing 2015 The Astrophysical journal Supplement series Vol.217 No.2
<P>In the Spring of 2011 we carried out a 2.5 month reverberation mapping campaign using the 3 m Shane telescope at Lick Observatory, monitoring 15 low-redshift Seyfert 1 galaxies. This paper describes the observations, reductions and measurements, and data products from the spectroscopic campaign. The reduced spectra were fitted with a multicomponent model in order to isolate the contributions of various continuum and emission-line components. We present light curves of broad emission lines and the active galactic nucleus (AGN) continuum, and measurements of the broad H beta line widths in mean and rms spectra. For the most highly variable AGNs we also measured broad Ha line widths and velocity centroids from the nightly spectra. In four AGNs exhibiting the highest variability amplitudes, we detect anticorrelations between broad H beta width and luminosity, demonstrating that the broad-line region 'breathes' on short timescales of days to weeks in response to continuum variations. We also find that broad Ha velocity centroids can undergo substantial changes in response to continuum variations; in NGC 4593, the broad H beta velocity shifted by similar to 250 km s(-1) over a 1 month period. This reverberation-induced velocity shift effect is likely to contribute a significant source of confusion noise to binary black hole searches that use multi-epoch quasar spectroscopy to detect binary orbital motion. We also present results from simulations that examine biases that can occur in measurement of broad-line widths from rms spectra due to the contributions of continuum variations and photon-counting noise.</P>
THE LICK AGN MONITORING PROJECT 2011: Fe II REVERBERATION FROM THE OUTER BROAD-LINE REGION
Barth, Aaron J.,Pancoast, Anna,Bennert, Vardha N.,Brewer, Brendon J.,Canalizo, Gabriela,Filippenko, Alexei V.,Gates, Elinor L.,Greene, Jenny E.,Li, Weidong,Malkan, Matthew A.,Sand, David J.,Stern, Dan IOP Publishing 2013 The Astrophysical journal Vol.769 No.2
<P>The prominent broad Fe II emission blends in the spectra of active galactic nuclei have been shown to vary in response to continuum variations, but past attempts to measure the reverberation lag time of the optical Fe II lines have met with only limited success. Here we report the detection of Fe II reverberation in two Seyfert 1 galaxies, NGC 4593 and Mrk 1511, based on data from a program carried out at Lick Observatory in Spring 2011. Light curves for emission lines including H beta and Fe II were measured by applying a fitting routine to decompose the spectra into several continuum and emission-line components, and we use cross-correlation techniques to determine the reverberation lags of the emission lines relative to V-band light curves. In both cases, the measured lag (tau(cen)) of Fe II is longer than that of H beta, although the inferred lags are somewhat sensitive to the choice of Fe II template used in the fit. For spectral decompositions done using the Fe II template of Veron-Cetty et al., we find tau(cen)(Fe II)/tau(cen)(H beta) = 1.9 +/- 0.6 in NGC 4593 and 1.5 +/- 0.3 in Mrk 1511. The detection of highly correlated variations between Fe II and continuum emission demonstrates that the Fe II emission in these galaxies originates in photoionized gas, located predominantly in the outer portion of the broad-line region.</P>
THE LICK AGN MONITORING PROJECT 2011: DYNAMICAL MODELING OF THE BROAD-LINE REGION IN Mrk 50
Pancoast, Anna,Brewer, Brendon J.,Treu, Tommaso,Barth, Aaron J.,Bennert, Vardha N.,Canalizo, Gabriela,Filippenko, Alexei V.,Gates, Elinor L.,Greene, Jenny E.,Li, Weidong,Malkan, Matthew A.,Sand, David IOP Publishing 2012 The Astrophysical journal Vol.754 No.1
<P>We present dynamical modeling of the broad- line region (BLR) in the Seyfert 1 galaxy Mrk 50 using reverberation mapping data taken as part of the Lick AGN Monitoring Project (LAMP) 2011. We model the reverberation mapping data directly, constraining the geometry and kinematics of the BLR, as well as deriving a black hole mass estimate that does not depend on a normalizing factor or virial coefficient. We find that the geometry of the BLR in Mrk 50 is a nearly face-on thick disk, with a mean radius of 9.6(-0.9)(+1.2) light days, a width of the BLR of 6.9(-1.1)(+1.2) light days, and a disk opening angle of 25 +/- 10 deg above the plane. We also constrain the inclination angle to be 9(-5)(+7) deg, close to face-on. Finally, the black hole mass of Mrk 50 is inferred to be log(10)(M-BH/M-circle dot) = 7.57(-0.27)(+0.44). By comparison to the virial black hole mass estimate from traditional reverberation mapping analysis, we find the normalizing constant (virial coefficient) to be log(10) f = 0.78(-0.27)(+0.44), consistent with the commonly adopted mean value of 0.74 based on aligning the M-BH-sigma* relation for active galactic nuclei and quiescent galaxies. While our dynamical model includes the possibility of a net inflow or outflow in the BLR, we cannot distinguish between these two scenarios.</P>
THE LICK AGN MONITORING PROJECT: RECALIBRATING SINGLE-EPOCH VIRIAL BLACK HOLE MASS ESTIMATES
Park, Daeseong,Woo, Jong-Hak,Treu, Tommaso,Barth, Aaron J.,Bentz, Misty C.,Bennert, Vardha N.,Canalizo, Gabriela,Filippenko, Alexei V.,Gates, Elinor,Greene, Jenny E.,Malkan, Matthew A.,Walsh, Jonelle IOP Publishing 2012 The Astrophysical journal Vol.747 No.1
<P>We investigate the calibration and uncertainties of black hole (BH) mass estimates based on the single-epoch (SE) method, using homogeneous and high-quality multi-epoch spectra obtained by the Lick Active Galactic Nucleus (AGN) Monitoring Project for nine local Seyfert 1 galaxies with BH masses <10(8) M-circle dot. By decomposing the spectra into their AGNs and stellar components, we study the variability of the SE H beta line width (full width at half-maximum intensity, FWHMH beta or dispersion, sigma(H beta)) and of the AGN continuum luminosity at 5100 angstrom (L-5100). From the distribution of the 'virial products' (proportional to FWHMH beta 2 L-5100(0.5) or sigma(2)(H beta) L-5100(0.5)) measured from SE spectra, we estimate the uncertainty due to the combined variability as similar to 0.05 dex (12%). This is subdominant with respect to the total uncertainty in SE mass estimates, which is dominated by uncertainties in the size-luminosity relation and virial coefficient, and is estimated to be similar to 0.46 dex (factor of similar to 3). By comparing the H beta line profile of the SE, mean, and root-mean-square (rms) spectra, we find that the H beta line is broader in the mean (and SE) spectra than in the rms spectra by similar to 0.1 dex (25%) for our sample with FWHMH beta < 3000 km s(-1). This result is at variance with larger mass BHs where the difference is typically found to be much less than 0.1 dex. To correct for this systematic difference of the H beta line profile, we introduce a line-width dependent virial factor, resulting in a recalibration of SE BH mass estimators for low-mass AGNs.</P>
Stability of the Broad-line Region Geometry and Dynamics in Arp 151 Over Seven Years
Pancoast, A.,Barth, A. J.,Horne, K.,Treu, T.,Brewer, B. J.,Bennert, V. N.,Canalizo, G.,Gates, E. L.,Li, W.,Malkan, M. A.,Sand, D.,Schmidt, T.,Valenti, S.,Woo, J.-H.,Clubb, K. I.,Cooper, M. C.,Crawford American Astronomical Society 2018 The Astrophysical journal Vol.856 No.2
<P>The Seyfert 1 galaxy Arp 151 was monitored as part of three reverberation mapping campaigns spanning 2008-2015. We present modeling of these velocity-resolved reverberation mapping data sets using a geometric and dynamical model for the broad-line region (BLR). By modeling each of the three data sets independently, we infer the evolution of the BLR structure in Arp 151 over a total of 7 yr and constrain the systematic uncertainties in nonvarying parameters such as the black hole mass. We find that the BLR geometry of a thick disk viewed close to face-on is stable over this time, although the size of the BLR grows by a factor of similar to 2. The dynamics of the BLR are dominated by inflow, and the inferred black hole mass is consistent for the three data sets, despite the increase in BLR size. Combining the inference for the three data sets yields a black hole mass and statistical uncertainty of log(10)(M-BH/M-circle dot) = 6.82(-0.09)(+0.09) with a standard deviation in individual measurements of 0.13 dex.</P>
The Lick AGN Monitoring Project 2011: Dynamical Modeling of the Broad-line Region
Williams, Peter R.,Pancoast, Anna,Treu, Tommaso,Brewer, Brendon J.,Barth, Aaron J.,Bennert, Vardha N.,Buehler, Tabitha,Canalizo, Gabriela,Cenko, S. Bradley,Clubb, Kelsey I.,Cooper, Michael C.,Filippen American Astronomical Society 2018 The Astrophysical journal Vol.866 No.2
THE LOW-LUMINOSITY END OF THE RADIUS-LUMINOSITY RELATIONSHIP FOR ACTIVE GALACTIC NUCLEI
Bentz, Misty C.,Denney, Kelly D.,Grier, Catherine J.,Barth, Aaron J.,Peterson, Bradley M.,Vestergaard, Marianne,Bennert, Vardha N.,Canalizo, Gabriela,De Rosa, Gisella,Filippenko, Alexei V.,Gates, Elin IOP Publishing 2013 The Astrophysical journal Vol.767 No.2
<P>We present an updated and revised analysis of the relationship between the H beta broad-line region (BLR) radius and the luminosity of the active galactic nucleus (AGN). Specifically, we have carried out two-dimensional surface brightness decompositions of the host galaxies of nine new AGNs imaged with the Hubble Space Telescope Wide Field Camera 3. The surface brightness decompositions allow us to create 'AGN-free' images of the galaxies, from which we measure the starlight contribution to the optical luminosity measured through the ground-based spectroscopic aperture. We also incorporate 20 new reverberation-mapping measurements of the H beta time lag, which is assumed to yield the average H beta BLR radius. The final sample includes 41 AGNs covering four orders of magnitude in luminosity. The additions and updates incorporated here primarily affect the low-luminosity end of the R-BLR-L relationship. The best fit to the relationship using a Bayesian analysis finds a slope of alpha = 0.533(-0.033)(+0.035), consistent with previous work and with simple photoionization arguments. Only two AGNs appear to be outliers from the relationship, but both of them have monitoring light curves that raise doubt regarding the accuracy of their reported time lags. The scatter around the relationship is found to be 0.19 +/- 0.02 dex, but would be decreased to 0.13 dex by the removal of these two suspect measurements. A large fraction of the remaining scatter in the relationship is likely due to the inaccurate distances to the AGN host galaxies. Our results help support the possibility that the R-BLR-L relationship could potentially be used to turn the BLRs of AGNs into standardizable candles. This would allow the cosmological expansion of the universe to be probed by a separate population of objects, and over a larger range of redshifts.</P>