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1. What Does the Geometry of the Hβ BLR Depend On?

   https://doi.org/10.3847/1538-4357/accc84  

   Villafaña, Lizvette ; Williams, Peter R. ; Treu, Tommaso ; Brewer, Brendon J. ; Barth, Aaron J. ; U, Vivian ; Bennert, Vardha N. ; Guo, Hengxiao ; Bentz, Misty C. ; Canalizo, Gabriela ; et al ( May 2023 , The Astrophysical Journal)

   We combine our dynamical modeling black-hole mass measurements from the Lick AGN Monitoring Project 2016 sample with measured cross-correlation time lags and line widths to recover individual scale factors,f, used in traditional reverberation-mapping analyses. We extend our sample by including prior results from Code for AGN Reverberation and Modeling of Emission Lines (caramel) studies that have utilized our methods. Aiming to improve the precision of black-hole mass estimates, as well as uncover any regularities in the behavior of the broad-line region (BLR), we search for correlations betweenfand other AGN/BLR parameters. We find (i) evidence for a correlation between the virial coefficient${\log }_{10}(f_{\mathrm{mean},\sigma })$and black-hole mass, (ii) marginal evidence for a similar correlation between${\log }_{10}(f_{\mathrm{rms},\sigma })$and black-hole mass, (iii) marginal evidence for an anticorrelation of BLR disk thickness with${\log }_{10}(f_{\mathrm{mean},\mathrm{FWHM}})$and${\log }_{10}(f_{\mathrm{rms},\mathrm{FWHM}})$, and (iv) marginal evidence for an anticorrelation of inclination angle with${\log }_{10}(f_{\mathrm{mean},\mathrm{FWHM}})$,${\log }_{10}(f_{\mathrm{rms},\sigma })$, and${\log }_{10}(f_{\mathrm{mean},\sigma })$. Last, we find marginal evidence for a correlation between line-profile shape, when using the root-mean-square spectrum,${\log }_{10}{(\mathrm{FWHM}/\sigma )}_{\mathrm{rms}}$, and the virial coefficient,${\log }_{10}(f_{\mathrm{rms},\sigma })$, and investigate how BLR properties might be related to line-profile shape usingcaramelmodels.

    

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2. Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. XIII. Ultraviolet Time Lag of Hβ Emission in Mrk 142

   https://doi.org/10.3847/1538-4357/acfb72  

   Khatu, Viraja C. ; Gallagher, Sarah C. ; Horne, Keith ; Cackett, Edward M. ; Hu, Chen ; Pasquini, Sofia ; Hall, Patrick ; Wang, Jian-Min ; Bian, Wei-Hao ; Li, Yan-Rong ; et al ( November 2023 , The Astrophysical Journal)

   We performed a rigorous reverberation-mapping analysis of the broad-line region (BLR) in a highly accreting (L/L_Edd= 0.74–3.4) active galactic nucleus, Markarian 142 (Mrk 142), for the first time using concurrent observations of the inner accretion disk and the BLR to determine a time lag for the Hβλ4861 emission relative to the ultraviolet (UV) continuum variations. We used continuum data taken with the Niel Gehrels Swift Observatory in theUVW2 band, and the Las Cumbres Observatory, Dan Zowada Memorial Observatory, and Liverpool Telescope in thegband, as part of the broader Mrk 142 multiwavelength monitoring campaign in 2019. We obtained new spectroscopic observations covering the Hβbroad emission line in the optical from the Gemini North Telescope and the Lijiang 2.4 m Telescope for a total of 102 epochs (over a period of 8 months) contemporaneous to the continuum data. Our primary result states a UV-to-Hβtime lag of${8.68}_{-0.72}^{+0.75}$days in Mrk 142 obtained from light-curve analysis with a Python-based running optimal average algorithm. We placed our new measurements for Mrk 142 on the optical and UV radius–luminosity relations for NGC 5548 to understand the nature of the continuum driver. The positions of Mrk 142 on the scaling relations suggest that UV is closer to the “true” driving continuum than the optical. Furthermore, we obtain$\log (M_{•}/M_{\odot })$= 6.32 ± 0.29 assuming UV as the primary driving continuum.

    

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3. Reverberation Mapping of IC 4329A

   https://doi.org/10.3847/1538-4357/acab62  

   Bentz, Misty C. ; Onken, Christopher A. ; Street, Rachel ; Valluri, Monica ( February 2023 , The Astrophysical Journal)

   We present the results of a new reverberation mapping campaign for the broad-line active galactic nucleus (AGN) in the edge-on spiral IC 4329A. Monitoring of the optical continuum withV-band photometry and broad emission-line flux variability with moderate-resolution spectroscopy allowed emission-line light curves to be measured for Hβ, Hγ, and Heiiλ4686. We find a time delay of${16.3}_{-2.3}^{+2.6}$days for Hβ, a similar time delay of${16.0}_{-2.6}^{+4.8}$days for Hγ, and an unresolved time delay of$-{0.6}_{-3.9}^{+3.9}$days for Heii. The time delay for Hβis consistent with the predicted value from the relationship between AGN luminosity and broad-line region radius, after correction for the ∼2.4 mag of intrinsic extinction at 5100 Å. Combining the measured time delay for Hβwith the broad emission-line width and an adopted value of 〈f〉 = 4.8, we find a central supermassive black hole mass of$M_{\mathrm{BH}}={6.8}_{-1.1}^{+1.2}\times {10}^7$M_⊙. Velocity-resolved time delays were measured across the broad Hβemission-line profile and may be consistent with an “M”-like shape. Modeling of the full reverberation response of Hβwas able to provide only modest constraints on some parameters, but does exhibit agreement with the black hole mass and average time delay. The models also suggest that the AGN structure is misaligned by a large amount from the edge-on galaxy disk. This is consistent with expectations from the unified model of AGNs, in which broad emission lines are expected to be visible only for AGNs that are viewed at relatively face-on inclinations.

    

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4. The Broad Line Region and Black Hole Mass of NGC 4151

   https://doi.org/10.3847/1538-4357/ac7c0a  

   Bentz, Misty C. ; Williams, Peter R. ; Treu, Tommaso ( August 2022 , The Astrophysical Journal)

   We present a reanalysis of reverberation mapping data from 2005 for the Seyfert galaxy NGC 4151, supplemented with additional data from the literature to constrain the continuum variations over a significantly longer baseline than the original monitoring program. Modeling of the continuum light curve and the velocity-resolved variations across the Hβemission line constrains the geometry and kinematics of the broad line region (BLR). The BLR is well described by a very thick disk with similar opening angle (θ_o≈ 57°) and inclination angle (θ_i≈ 58°), suggesting that our sight line toward the innermost central engine skims just above the surface of the BLR. The inclination is consistent with constraints from geometric modeling of the narrow-line region, and the similarity between the inclination and opening angles is intriguing given previous studies of NGC 4151 that suggest BLR gas has been observed temporarily eclipsing the X-ray source. The BLR kinematics are dominated by eccentric bound orbits, with ∼10% of the orbits preferring near-circular motions. With the BLR geometry and kinematics constrained, the models provide an independent and direct black hole mass measurement of$\log M_{\mathrm{BH}}/M_{\odot }={7.22}_{-0.10}^{+0.11}$or$M_{\mathrm{BH}}={1.66}_{-0.34}^{+0.48}\times {10}^7$M_⊙, which is in good agreement with mass measurements from stellar dynamical modeling and gas dynamical modeling. NGC 4151 is one of the few nearby broad-lined Seyferts where the black hole mass may be measured via multiple independent techniques, and it provides an important test case for investigating potential systematics that could affect the black hole mass scales used in the local universe and for high-redshift quasars.

    

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5. Velocity-resolved Reverberation Mapping of NGC 3227

   https://doi.org/10.3847/1538-4357/ad08b8  

   Bentz, Misty C. ; Markham, Madison ; Rosborough, Sara ; Onken, Christopher A. ; Street, Rachel ; Valluri, Monica ; Treu, Tommaso ( December 2023 , The Astrophysical Journal)

   We describe the results of a new reverberation mapping program focused on the nearby Seyfert galaxy NGC 3227. Photometric and spectroscopic monitoring was carried out from 2022 December to 2023 June with the Las Cumbres Observatory network of telescopes. We detected time delays in several optical broad emission lines, with Hβhaving the longest delay at${\tau }_{\mathrm{cent}}={4.0}_{-0.9}^{+0.9}$days and Heiihaving the shortest delay with${\tau }_{\mathrm{cent}}={0.9}_{-0.8}^{+1.1}$days. We also detect velocity-resolved behavior of the Hβemission line, with different line-of-sight velocities corresponding to different observed time delays. Combining the integrated Hβtime delay with the width of the variable component of the emission line and a standard scale factor suggests a black hole mass of$M_{\mathrm{BH}}={1.1}_{-0.3}^{+0.2}\times {10}^7$M_⊙. Modeling of the full velocity-resolved response of the Hβemission line with the phenomenological codeCARAMELfinds a similar mass of$M_{\mathrm{BH}}={1.2}_{-0.7}^{+1.5}\times {10}^7$M_⊙and suggests that the Hβ-emitting broad-line region (BLR) may be represented by a biconical or flared disk structure that we are viewing at an inclination angle ofθ_i≈ 33° and with gas motions that are dominated by rotation. The new photoionization-based BLR modeling toolBELMACfinds general agreement with the observations when assuming the best-fitCARAMELresults; however,BELMACprefers a thick-disk geometry and kinematics that are equally composed of rotation and inflow. Both codes infer a radially extended and flattened BLR that is not outflowing.

    

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