相关论文: A novel approach to study the variability of NGC 5…
We present the final installment of an intensive 13-year study of variations of the optical continuum and broad H-beta emission line in the Seyfert 1 galaxy NGC 5548. The data base consists of 1530 optical continuum measurements and 1248…
The variability of virial factor $f$ is investigated for two active galactic nucleus, NGC 5548 and NGC 4151, which had been previously reverberation mapped (RM) over 20 times in the past 30 years. Using four velocity tracers from the broad…
We present the results of three years of ground-based observations of the Seyfert 1 galaxy NGC 5548, which combined with previously reported data, yield optical continuum and broad-line H-beta light curves for a total of eight years. The…
We present an analysis of 43 years (1972 to 2015) of spectroscopic observations of the Seyfert 1 galaxy NGC 5548. This includes 12 years of new unpublished observations (2003 to 2015). We compiled about 1600 H$\beta$ spectra and analyzed…
NGC 5548 has been hailed as an archetypical type-1 active galactic nuclei (AGN) and serves as a valuable laboratory to study the long-term variation of its broad-line region (BLR). In this work, we re-affirm our finding on the connection…
We investigate the possibility of an intrinsic Baldwin Effect (i.e.,nonlinear emission-line response to continuum variations) in the broad H-beta emission line of the active galaxy NGC 5548 using cross-correlation techniques to remove light…
NGC 5548 is the best-observed reverberation-mapped active galactic nucleus with long-term, intensive monitoring. Here we report results from a new observational campaign between January and July, 2015. We measure the centroid time lag of…
Results of a long-term monitoring ($\gtrsim 10$ years) of the broad line and continuum fluxes of three Active Galactic Nuclei (AGN), 3C 390.3, NGC 4151, and NGC 5548, are presented. We analyze the H$\alpha$ and H$\beta$ profile variations…
NGC 5548 has been well spectroscopically monitored for reverberation mapping of the central kinematics by 19 campaigns. Using the maximum entropy method in this Letter, we build up a high-quality velocity-delay map of the H$\beta$ emission…
We report the results of long-term reverberation mapping (RM) campaigns of the nearby active galactic nuclei (AGN) NGC 4151, spanning from 1994 to 2022, based on archived observations of the FAST Spectrograph Publicly Archived Programs and…
A detailed analysis of the data from a high sampling rate, multi-month reverberation mapping campaign, undertaken primarily at MDM Observatory with supporting observations from telescopes around the world, reveals that the Hbeta emission…
We report preliminary results on the analysis of the continuum and H$\beta$ light curves of the type-1 active galactic nucleus (AGN) NGC 5548. We notice a clear signature of shallowing in the trend between the H$\beta$ and the continuum…
Line broadening and variability are observational hallmarks of active galactic nuclei which allow us to measure supermassive black hole masses as well as constrain the geometry and kinematics of the emitting gas, with the most precise…
We present the results of an optical spectroscopic monitoring program targeting NGC 5548 as part of a larger multi-wavelength reverberation mapping campaign. The campaign spanned six months and achieved an almost daily cadence with…
In the standard AGN reverberation-mapping model, variations in broad-line region (BLR) fluxes are predicted from optical continuum variability (taken as a proxy for the ionizing continuum) convolved with a response function that depends on…
Active galactic nuclei (AGNs) exhibit complex variability across multiple wavelengths, reflecting diverse physical processes near their central engines. This work investigates the temporal variability of four AGNs Mrk~509, NGC~5548,…
Between 1996 and 2002, we have carried out a spectral monitoring program for the Seyfert galaxy NGC 5548. High quality spectra (S/N>50), covering the spectral range (4000-7500)AA were obtained with the 6 m and 1 m telescopes of SAO (Russia)…
During the 2014 HST/Swift and ground-based multi-wavelength monitoring campaign of NGC 5548 (AGN STORM), the UV-optical broad emission lines exhibited anomalous, decorrelated behaviour relative to the far-UV continuum flux variability.…
We present geometric and dynamical modeling of the broad line region for the multi-wavelength reverberation mapping campaign focused on NGC 5548 in 2014. The dataset includes photometric and spectroscopic monitoring in the optical and…
Results of the long-term (11 years, from 1996 to 2006) H$\alpha$ and H$\beta$ line variations of the active galactic nucleus of NGC 4151 are presented. High quality spectra (S/N>50 and R~8A) of H$\alpha$ and H$\beta$ were investigated. We…