40 citations · 395 across the 33 of their papers we have counts for
29 papers · 1 filter
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…
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…
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…
Quasi-simultaneous Spectroscopic and Multi-band Photometric Observations of Blazar S5 0716+714 during 2018-2019
Hai-Cheng. Feng, H. T. Liu, J. M. Bai +4
In order to study short timescale optical variability of -ray blazar S5 0716+714, quasi-simultaneous spectroscopic and multi-band photometric observations were performed from 20…
Active Galactic Nuclei with Ultra-fast Outflows Monitoring Project: The Broad-line Region of Mrk 79 as a Disk Wind
Kai-Xing Lu, Jin-Ming Bai, Zhi-Xiang Zhang +23
We developed a spectroscopic monitoring project to investigate the kinematics of the broad-line region (BLR) in active galactic nuclei (AGN) with ultra-fast outflows (UFOs). Mrk~79…
Search for Intra-day Optical Variability in -ray--loud Blazars S5 0716+714 and 3C 273
H. T. Liu, Hai Cheng Feng, Y. X. Xin +3
We present the photometric observations of blazars S5 0716+714 and 3C 273 with high temporal resolution (30--60s) in the or bands. The observations were performed with a 1.…