The Seoul National University AGN Monitoring Project. III. Hβ Lag Measurements of 32 Luminous Active Galactic Nuclei and the High-luminosity End of the Size–Luminosity Relation
Jong-Hak Woo, Shu Wang, Suvendu Rakshit, Hojin Cho, Donghoon Son, Vardha N. Bennert, Elena Gallo, Edmund Hodges‐Kluck, Tommaso Treu, Aaron J. Barth, Wanjin Cho, Adi Foord, Jaehyuk Geum, Hengxiao Guo, Yashashree Jadhav, Yiseul Jeon, Kyle M. Kabasares, Won-Suk Kang, Changseok Kim, Minjin Kim, Taewoo Kim, Huynh Anh N. Le, Matthew A. Malkan, Amit Kumar Mandal, Daeseong Park, Chance Spencer, Jaejin Shin, Hyun-Il Sung, U Vivian, P. R. Williams, Nick Yee
Abstract
Abstract We present the main results from a long-term reverberation mapping campaign carried out for the Seoul National University AGN Monitoring Project (SAMP). High-quality data were obtained during 2015–2021 for 32 luminous active galactic nuclei (AGNs; i.e., continuum luminosity in the range of 10 44–46 erg s −1 ) at a regular cadence, of 20–30 days for spectroscopy and 3–5 days for photometry. We obtain time lag measurements between the variability in the H β emission and the continuum for 32 AGNs; 25 of those have the best lag measurements based on our quality assessment, examining correlation strength and the posterior lag distribution. Our study significantly increases the current sample of reverberation-mapped AGNs, particularly at the moderate-to-high-luminosity end. Combining our results with literature measurements, we derive an H β broadline region size–luminosity relation with a shallower slope than reported in the literature. For a given luminosity, most of our measured lags are shorter than the expectations, implying that single-epoch black hole mass estimators based on previous calibrations could suffer large systematic uncertainties.