Detailed Record


Broad-line region in NGC 4151 monitored by two decades of reverberation mapping campaigns – I. Evolution of structure and kinematics


Abstract ABSTRACT We report the results of long-term reverberation mapping campaigns of the nearby active galactic nuclei (AGNs) NGC 4151, spanning from 1994 to 2022, based on archived observations of the FAST Spectrograph Publicly Archived Programs and our new observations with the 2.3 m telescope at the Wyoming Infrared Observatory. We reduce and calibrate all the spectra in a consistent way, and derive light curves of the broad H β line and 5100 Å continuum. Continuum light curves are also constructed using public archival photometric data to increase sampling cadences. We subtract the host galaxy contamination using Hubble Space Telescope imaging to correct fluxes of the calibrated light curves. Utilizing the long-term archival photometric data, we complete the absolute flux-calibration of the AGN continuum. We find that the H β time delays are correlated with the 5100 Å luminosities as $\tau _{\rm H\beta }\propto L_{5100}^{0.46\pm 0.16}$. This is remarkably consistent with Bentz et al. (2013)’s global size–luminosity relationship of AGNs. Moreover, the data sets for five of the seasons allow us to obtain the velocity-resolved delays of the H β line, showing diverse structures (outflows, inflows, and discs). Combining our results with previous independent measurements, we find the measured dynamics of the H β broad-line region (BLR) are possibly related to the long-term trend of the luminosity. There is also a possible additional ∼1.86 yr time lag between the variation in BLR radius and luminosity. These results suggest that dynamical changes in the BLR may be driven by the effects of radiation pressure.
Authors Yong-Jie Chen ORCID , Dong-Wei Bao ORCID , Shuo Zhai , Feng-Na Fang , Chen Hu ORCID , Pu Du ORCID , Sen Yang ORCID , Zhu-Heng Yao ORCID , Yanrong Li ORCID , Michael S. Brotherton University of WyomingORCID , Jacob N. McLane University of WyomingORCID , T. E. Zastrocky University of WyomingORCID , Kianna A. Olson University of Wyoming , E. Bon ORCID , Hua-Rui Bai ORCID , Yi-Xin Fu , Junrong Liu ORCID , Yilin Wang ORCID , Jaya Maithil University of WyomingORCID , Henry A. Kobulnicky University of WyomingORCID , Daniel A. Dale University of WyomingORCID , C. Adelman University of Wyoming , Mirielle Caradonna University of Wyoming , Z Carter University of Wyoming , J Favro University of Wyoming , A J Ferguson University of Wyoming , I M Gonzalez University of Wyoming , L M Hadding University of Wyoming , H D Hagler University of Wyoming , G Murphree University of Wyoming , M. Oeur University of WyomingORCID , Carl J. Rogers University of Wyoming , T. Roth University of Wyoming , S. Schonsberg University of Wyoming , T R Stack University of Wyoming , Jianmin Wang ORCID
Journal Info Oxford University Press | Monthly Notices of the Royal Astronomical Society , vol: 520 , iss: 2 , pages: 1807 - 1831
Publication Date 1/10/2023
ISSN 0035-8711
TypeKeyword Image article
Open Access green Green Access
DOI https://doi.org/10.1093/mnras/stad051
KeywordsKeyword Image Gravitational Lensing (Score: 0.471991)