Broad-line Region of the Quasar PG 2130+099 from a Two-year Reverberation Mapping Campaign with High Cadence

As one of the most interesting Seyfert 1 galaxies, PG 2130+099 has been the target of several reverberation mapping (RM) campaigns over the years. However, its measured broad Hβ line responses have been inconsistent, with time lags of ∼200 days, ∼25 days, and ∼10 days being reported for different epochs while its optical luminosity changed no more than 40%. To investigate this issue, we conducted a new RM-campaign with homogenous and high cadence (about ∼3 days) for two years during 2017-2019 to measure the kinematics and structure of the ionized gas. We successfully detected time lags of broad Hβ, He ii, He i, and Fe ii lines with respect to the varying 5100 Å continuum, revealing a stratified structure that is likely virialized with Keplerian kinematics in the first year of observations, but an inflow kinematics of the broad-line region from the second year. With a central black hole mass of 0.97+0.15 -0.18 × 107 Mo˙, PG 2130+099 has an accretion rate of 102.1 ± 0.5 LEdd c-2, where L Edd is the Eddington luminosity and c is speed of light, implying that it is a super-Eddington accretor and likely possesses a slim, rather than thin, accretion disk. The fast changes of the ionization structures of the three broad lines remain puzzling. © 2020. The American Astronomical Society. All rights reserved.The authors are grateful to an anonymous referee for very useful reports. The campaign made use of mainly the CAHA 2.2m, and jointly the Lijiang 2.4m and the Sutherland 1.9m telescopes, we acknowledge the support of the staff of these telescopes. This work is based on observations collected at the Centro Astronomico Hispanoen Andalucia (CAHA) at Calar Alto, operated jointly by the Andalusian Universities and the Instituto de Astrofisica de Andalucia (CSIC). Funding for the Lijiang 2.4m telescope has been provided by Chinese Academy of Sciences (CAS) and the People's Government of Yunnan Province. This research is supported by grant 2016YFA0400700 from the Ministry of Science and Technology of China, by NSFC grants NSFC-11773029, -11833008, -11991054, -11922304, -11873048, -11690024, and -11703077, by the CAS Key Research Program through KJZD-EW-M06, by the Key Research Program of Frontier Sciences, CAS, grant QYZDJ-SSWSLH007.Peer reviewe