40 citations · 395 across the 33 of their papers we have counts for
33 papers
First detection of ultra-fast outflows in a quiescent galaxy
Yerong Xu, Malgorzata Siudek, Victor Rodríguez Morales +7
Outflows in active galactic nuclei (AGN) are recognized as a fundamental mechanism driving the co-evolution of supermassive black holes (SMBHs) and their host galaxies. Although po…
The Most Luminous H Reverberation Mapping of E1821+643 Indicates the Lower Boundary of the Radius-Luminosity Relation
Sha-Sha Li, Hai-Cheng Feng, Jiancheng Wu +5
The radius-luminosity (-) relation is fundamental to active galactic nucleus (AGN) studies, enabling supermassive black hole (SMBH) mass estimates and AGN-ba…
Discovery of a Luminosity-dependent Continuum Lag in NGC 4151 from Photometric and Spectroscopic Continuum Reverberation Mapping
Hai-Cheng Feng, Sha-Sha Li, Mouyuan Sun +17
Accretion onto supermassive black holes (SMBHs) powers active galactic nuclei (AGNs) and drives feedback that shapes galaxy evolution. Constraining AGN accretion disk structure is…
Supermassive Black Hole and Broad-line Region in NGC 5548: 2023 Reverberation Mapping Results
Wen-Zhe Xi, Kai-Xing Lu, Jin-Ming Bai +6
We present the results of the 2023 spectroscopic reverberation mapping (RM) campaign for active galactic nuclei (AGN) of NGC 5548, continuing our long-term monitoring program. Usin…
Accretion-Regulated Type Transitions in Changing-Look AGNs: Evidence from Two-Epoch Spectral Analysis
Yu-Heng Shen, Kai-Xing Lu, Wei-Jian Guo +6
The changing-look active galactic nucleus (CL-AGN), an extraordinary subpopulation of supermassive black holes, has attracted growing attention for understanding its nature. We pre…
Reverberation Mapping of Two Variable Active Galactic Nuclei: Probing the Distinct Characteristics of the Inner and Outer Broad-line Regions
Hai-Cheng Feng, Sha-Sha Li, J. M. Bai +8
Current reverberation mapping (RM) studies primarily focus on single emission lines, particularly the \hb\ line, which may not fully reveal the geometry and kinematic properties of…
A Short-lived Rejuvenation during the Decades-long Changing-look Transition in the Nucleus of Mrk 1018
Kai-Xing Lu, Yan-Rong Li, Qingwen Wu +13
Changing-look active galactic nuclei (CL-AGNs), characterized by emerging or disappearing of broad lines accompanied with extreme continuum flux variability, have drawn much attent…
Velocity-resolved Reverberation Mapping of Changing-look Active Galactic Nucleus NGC 4151 during Outburst Stage. II. Four Season Observation Results
Hai-Cheng Feng, Sha-Sha Li, J. M. Bai +7
We present the results of a four-year velocity-resolved reverberation mapping (RM) campaign of the changing-look active galactic nucleus (CL-AGN) NGC 4151 during its outburst phase…
Velocity-Resolved Ionization Mapping of Broad Line Region. I. Insights into Diverse Geometry and Kinematics
Sha-Sha Li, Hai-Cheng Feng, H. T. Liu +6
Broad emission lines of active galactic nuclei (AGNs) originate from the broad-line region (BLR), consisting of dense gas clouds in orbit around an accreting supermassive black hol…
Unprecedented Continuum Time Delay Variation Phenomenon in an Active Supermassive Black Hole
Shuying Zhou, Mouyuan Sun, Hai-Cheng Feng +12
Resolving the accretion disks and broad line regions (BLRs) of active galactic nuclei (AGNs) can probe the physics behind supermassive black holes (SMBHs) fueling and weigh SMBHs.…
Morpho-Photometric Classification of KiDS DR5 Sources Based on Neural Networks: A Comprehensive Star-Quasar-Galaxy Catalog
Hai-Cheng Feng, Rui Li, Nicola R. Napolitano +14
We present a novel multimodal neural network (MNN) for classifying astronomical sources in multiband ground-based observations, from optical to near infrared, to separate sources i…
Optical Continuum Reverberation Mapping of a Candidate IMBH in a Nearby Seyfert 1 Galaxy
Wenwen Zuo, Hengxiao Guo, Jingbo Sun +25
To investigate the short-term variability and determine the size of the optical continuum emitting region of intermediate-mass black holes (IMBHs), we carried out high-cadence, mul…
Correcting the Contamination of Second-order Spectra: Improving Hα Measurements in Reverberation Mapping Campaigns
Wen-Zhe Xi, Kai-Xing Lu, Hai-Cheng Feng +5
Long-term spectroscopic monitoring campaigns on active galactic nuclei (AGNs) provide a wealth of information about its interior structure and kinematics. However, a number of the…
Measuring the Virial Factor in SDSS DR7 AGNs with Redshifted H and H Broad Emission Lines
H. T. Liu, Hai-Cheng Feng, Sha-Sha Li +2
Under the hypothesis of gravitational redshift induced by the central supermassive black hole, and based on line widths and shifts of redward shifted H and H broad emission l…
Toward a stellar population catalog in the Kilo Degree Survey: the impact of stellar recipes on stellar masses and star formation rates
Linghua Xie, Nicola R. Napolitano, Xiaotong Guo +11
The Kilo Degree Survey (KiDS) is currently the only sky survey providing optical () plus near-infrared (NIR, ) seeing matched photometry over an area larger than 100…
Deep HI Mapping of Stephan's Quintet and Its Neighborhood
Cheng Cheng, Cong Kevin Xu, P. N. Appleton +8
We carried out deep mapping observations of the atomic hydrogen (HI) 21 cm line emission in a field centered on the famous galaxy group Stephan's Quintet (SQ), using the Five-hundr…
Supermassive Black Hole and Broad-line Region in NGC~5548: Results from Five-season Reverberation Mapping
Kai-Xing Lu, Jin-Ming Bai, Jian-Min Wang +9
NGC 5548 is one of the active galactic nuclei (AGN) selected for our long-term spectroscopic monitoring with the Lijiang 2.4~m telescope, aiming at investigating the origin and evo…
Velocity-resolved Reverberation Mapping of Changing-look Active Galactic Nucleus NGC~4151 During Outburst Stage: Evidence for Kinematics Evolution of Broad-line Region
Sha-Sha Li, Hai-Cheng Feng, H. T. Liu +6
Changing-look active galactic nucleus NGC~4151, which has attracted a lot of attention, is undergoing the second dramatic outburst stage in its evolutionary history. To investigate…
Measuring the Virial Factor in SDSS DR5 Quasars with Redshifted H and Fe ii Broad Emission Lines
H. T. Liu, Hai-Cheng Feng, Sha-Sha Li +1
Under the hypothesis of gravitational redshift induced by the central supermassive black hole, and based on line widths and shifts of redward shifted H and Fe ii broad emission…
Reverberation Mapping Measurements of Black Hole Masses and Broad-Line Region Kinematics in Mrk 817 and NGC 7469
Kai-Xing Lu, Jian-Guo Wang, Zhi-Xiang Zhang +7
We present the results from a spectroscopic monitoring campaign to obtain reverberation-mapping measurements and investigate the broad-line region kinematics for active galactic nu…
A correction method for the telluric absorptions and application to Lijiang Observatory
Kai-Xing Lu, Zhi-Xiang Zhang, Ying-Ke Huang +7
Observing a telluric standard star for correcting the telluric absorption lines of spectrum will take a significant amount of precious telescope time, especially in the long-term s…
Velocity-resolved Reverberation Mapping of Changing-look AGN NGC 2617
Hai-Cheng. Feng, H. T. Liu, J. M. Bai +6
NGC 2617 has attracted a lot of attention after the detection of the changes in spectral type, and its geometry and kinematics of broad-line region (BLR) are still ambiguous. In th…
Reverberation Mapping of Changing-look Active Galactic Nucleus NGC 3516
Hai-Cheng. Feng, Chen. Hu, Sha-Sha. Li +7
The changes of broad emission lines should be a crucial issue to understanding the physical properties of changing-look active galactic nucleus (CL-AGN). Here, we present the resul…
Spectroscopic Monitoring of Blazar S5 0716+714: Brightness-Dependent Spectral Behavior
Hai-Cheng Feng, Sen. Yang, Zi-Xu. Yang +17
In this paper, we report the new results of spectroscopic observations of -ray blazar S5 0716+714 from 2019 September to 2020 March with the 2.4 m optical telescope at Lijiang O…