A5107481221- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Galaxies: Formation, Evolution, Phenomena
- Gamma-ray bursts and supernovae
- Radio Astronomy Observations and Technology
- Dark Matter and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Solar and Space Plasma Dynamics
- Neutrino Physics Research
- Geophysics and Gravity Measurements
- Mechanics and Biomechanics Studies
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Nanomaterials for catalytic reactions
- Ammonia Synthesis and Nitrogen Reduction
- Astro and Planetary Science
- Particle Detector Development and Performance
- Computational Physics and Python Applications
- Particle physics theoretical and experimental studies
- High-pressure geophysics and materials
- Particle Accelerators and Free-Electron Lasers
- Nuclear Physics and Applications
- Advanced X-ray Imaging Techniques
- Black Holes and Theoretical Physics
Huazhong University of Science and Technology
2016-2025
Southeast University
2024
Tibet University
2021-2023
Astronomy and Space
2023
National Center for Supercomputing Applications
2023
University of Illinois Urbana-Champaign
2023
Anhui Normal University
2018
Korea Astronomy and Space Science Institute
2007-2010
Space Science Institute
2008
Shanghai Astronomical Observatory
2005-2008
Abstract Changing-look active galactic nuclei (CL-AGNs), characterized by the emergence or disappearance of broad lines accompanied extreme continuum flux variability, have drawn much attention for their potential to reveal physical processes underlying AGN evolution. We perform seven-season spectroscopic monitoring on Mrk1018, one earliest identified CL-AGN. Around 2020, we detect a full-cycle changing-look transition Mrk 1018 within year, associated with nucleus outburst, which likely...
Abstract Changing-look blazars (CLBs) are whose optical spectral lines at different epochs show significant changes and present a clear transition between standard FSRQ BL Lacertae (BL Lac). Changing-look phenomena in highly for enhancing our understanding of certain physical problems active galactic nuclei (AGNs), such as the potential mechanism state accretion process supermassive black holes central engine AGNs, possible intrinsic variation jet, connection disk jet. Currently, CLBs...
We investigate the relationship between hard X-ray photon index $Γ$ and Eddington ratio ($ξ=L_{X}(0.5-25 \rm keV)/L_{Edd}$) in six binaries (XRBs) with well constrained black hole masses distances. find that different XRBs follow anti-correlations $ξ$ when is less than a critical value, while generally same positive correlation larger value. The anti-correlation may suggest they are accretion modes (e.g., radiatively inefficient flow (RIAF) standard disk). fit both correlations linear...
The bulk Lorentz factor of the gamma-ray burst (GRB) ejecta (Γ0) is a key parameter to understanding GRB physics. Liang et al. have discovered correlation between Γ0 and isotropic γ-ray energy: Γ0∝E0.25γ, iso, 52. By including more GRBs with updated data methods derive Γ0, we confirm this obtain ≃ 91E0.29γ, Evaluating mean luminosities Lγ, iso in same sample, discover an even tighter 249L0.30γ, We propose interpretation later correlation. Invoking neutrino-cooled hyperaccretion disk around...
We fit the (quasi-)simultaneous multi-waveband spectral energy distributions (SEDs) for a sample of low-synchrotron-peaked (LSP) blazars with one-zone leptonic model. The seed photons that predominantly come from broad line region (BLR) and infrared (IR) molecular torus are considered respectively in external Compton process. find modeling IR is systematically better than BLR based on $\chi^2$ test, which suggest $\gamma$-ray emitting most possibly stay outside BLR. minimum electron Lorentz...
Quasi-periodic eruptions (QPEs) are found in the center of five galaxies, where a tidal disruption event (TDE)-like is also reported GSN 069 that happened couple years before QPEs. We explain connection these phenomena based on model highly eccentric white-dwarf (WD)-$10^{4-6}M_{\odot}$ massive black hole (MBH) binary formed by Hill mechanism. In this system, induced internal oscillation WD can heat envelope thereby induces nova and inflates envelope, which be captured MBH form TDE. The...
Quasar outflows may play a crucial role in regulating the host galaxy, although spatial scale of quasar remain major enigma, with their acceleration mechanism poorly understood. The kinematic information outflow is key to understanding its origin and mechanism. Here, we report galactocentric distances different components for both sample an individual quasar. We find that distance increases velocity, typical value from several parsecs more than one hundred parsecs, providing direct evidence...
Recent observations show that the metallicity of broad line region ($Z_{\rm BLR}$) in active galactic nuclei (AGNs) is solar-to-supersolar, which positively correlated with mass supermassive black holes ($M_{\rm BH}$) and does not evolve redshift up to $z \sim 7$. We revisit $M_{\rm BH}-Z_{\rm BLR}$ correlation more AGNs BH}\sim 10^{6-8} M_{\odot}$ find positive become flat low-mass range. It known outer part accretion disks gravitationally unstable can fragment into stars. Considering star...
Abstract Changing-look active galactic nuclei (AGNs) are a special class of AGNs that change their spectral type from 1 to 2 or vice versa. In recent years, number changing-look blazars (CLBs) were also reported, which transition between flat-spectrum radio quasars and BL Lacs. The physical properties CLBs still unclear. Using the mclust R package for Gaussian mixture modeling, we performed clustering analysis sample 105 selected literature. Three kinds found lie in parameter distributions...
We investigate the origin of X-ray emission in FR I galaxies using radio, submillimeter, optical, and Chandra data for a small sample eight sources. These sources are very dim, with luminosities LX/LEdd ~ 10-4 to 10-8 (with LX luminosity between 2 10 keV). try fit multi-wave-band spectra coupled accretion-jet model. In this model, accretion is described by an advection-dominated flow (ADAF); innermost region ADAF, fraction transferred into vertical direction forms jet. find that source...
In recent years, it was found that there are several low/hard state of X-ray binaries (XRBs) follow an `outliers' track radio--X-ray correlation ($L_{\rm R}\propto L_{\rm X}^{b}$ and $b\sim1.4$), which is much steeper than the former universal with $b\sim0.6$. this work, we compile a sample bright radio-quiet active galactic nuclei (AGNs) find their hard photon indices Eddington ratios positively correlated, similar to XRBs, where both AGNs XRBs have bolometric $\gtrsim1%L_{\rm Edd}$...
Recent observations suggest that in black hole X-ray binaries jet/outflow formation is related to the hot plasma vicinity of hole, either form an advection-dominated accretion flow at low rates or a disk corona high rates. We test viability this scenario for supermassive holes using two samples active galactic nuclei distinguished by presence (radio-strong) and absence (radio-weak) well-collimated, relativistic jets. Each centered on narrow range mass but spans very broad Eddington ratios,...
Abstract The discovery of changing-look active galactic nuclei (CLAGNs) with a significant change in optical broad emission lines (optical CLAGNs) and/or strong variation line-of-sight column densities (X-ray challenges the orientation-based AGN unification model. We explore mid-infrared (mid-IR) properties for sample 57 CLAGNs and 11 X-ray based on Wide-field Infrared Survey Explorer archive data. find that Eddington-scaled mid-IR luminosities both stay just between those low-luminosity...
Context. Unusually, there are still certain characteristics of the changing-look (CL) active galactic nuclei (AGNs) that remain undetected. Consequently, trigger mechanism behind CL phenomenon observed in partial AGNs remains unknown. Aims. We explore light curve and spectral energy distribution (SED) blazar OQ 334 as obtained by Fermi -LAT. Methods. By examining variability equivalent width (EW), we categorise -LAT curves during epoch MJD 54628−58677 into seven distinct epochs, including...
Gas accretion of embedded stellar-mass black holes\,(sBHs) or stars in the disk active galactic nuclei\,(AGNs) will modify mass distribution these sBHs and stars, which also affect migration sBHs/stars. With introduction effect, we simulate evolution sBH/star function a consistent way by extending Fokker-Planck equation distributions to mass-varying scenario, explore nuclear region galaxy centre. We find that can grow up several tens solar form heavier sBH binaries, be helpful for us...
Abstract Tidal disruption events (TDEs) provide a valuable probe for studying the dynamics of stars in nuclear environments galaxies. Recent observations show that TDEs are strongly overrepresented post-starburst or “green valley” galaxies, although underlying physical mechanism remains unclear. Considering possible interaction between and active galactic nucleus (AGN) disks, TDE rates can be greatly changed compared to those quiescent nuclei. In this work, we revisit by incorporating an...
Aims. We discovered that the changing-look active galactic nucleus (CLAGN) SDSS J101152.98+544206.4 (J1011+5442 for short) gradually returns to type I state after a short period between 2014 and 2019 in faint 1.9 state. Methods. Motivated by rebrightening optical mid-infrared light curves from ZTF WISE, we obtained new spectroscopic observations with Xinglong 2.16 m, Lijiang 2.4 MMT 6.5 m telescopes 2024. Results. After changing its AGN 1 2003 2015 according repeat spectroscopy Time Domain...
Abstract Changing-look active galactic nuclei (CLAGNs) are known to change their spectral type between 1 and 2 (changing-state) or absorption Compton-thick Compton-thin (changing-obscuration) on timescales of years less. The physical mechanism possible connection the two types CLAGNs still unclear. We explore evolution broadband X-ray spectra from Nuclear Spectroscopic Telescope Array (NuSTAR ) column density in five with moderate inclination viewing angles, which have shown significant...
Abstract The geometry and kinematics of the broad-line region (BLR) in active galactic nuclei (AGNs) are still unclear, which is crucial for studying physics evolution supermassive black holes AGNs. profile provides valuable information on BLR kinematics. In this work, we explore line profiles variable AGNs based model Czerny Hryniewicz, where driven by radiation pressure acting dust at surface layers accretion disk. low-Eddington-ratio regime show a double-peak profile, will become single...
Abstract Stellar-mass binary black hole (BBH) mergers within the accretion disks of active galactic nuclei may contribute to gravitational wave (GW) events detected by ground-based GW detectors. In particular, interaction between a BBH and single stellar-mass (sBH), known as binary-single (BSI) process, can potentially lead with detectable nonzero eccentricity. Previous studies BSI which neglected effects gas, showed that BSIs non-negligibly in coplanar disk environment. this work, we...
In the frame of unification schemes for radio-loud active galactic nuclei (AGNs), FR I radio galaxies are believed to be BL Lacertae (BL Lac) objects with relativistic jet misaligned our line sight, and II correspond quasars. The Ledlow–Owen dividing I/FR dichotomy in optical absolute magnitude host galaxy–radio luminosity (MR–LRad) plane can translated black hole mass–jet power (Mbh–Qjet) by using two empirical relations: Qjet–LRad Mbh–MR. We use a sample quasars Lac measured masses explore...
The BH masses and the Eddington ratios for a sample of 65 young radio galaxies [27 GPS 38 CSS sources] are estimated by various methods. We find that average mass these is <log M_bh>=8.3, which less than loud QSOs low redshift galaxies(<log M_bh>=9.0). CSS/GPS sources have relatively high with ratio L_bol/L_Edd>=-0.56, similar to those narrow line Seyfert 1 (NLS1s). It suggests may not only be in early stage activities, but also their accretion activities. as class deviate systematically...
We investigate the correlation between 151 MHz radio luminosity, L151 MHz, and jet power, Pjet, for a sample of low-power galaxies, which power is estimated from X-ray cavities. The Fanaroff–Riley I galaxies (FR Is) with derived empirical correlation. find that Pjet/LEdd positively correlated FR Is, where LEdd Eddington luminosity L2–10 keVX 2–10 keV luminosity. calculate hybrid model, as variant Blandford–Znajek model proposed by Meier, based on global solution advection-dominated accretion...
Abstract The millimetre bump, as found in high-resolution multiwaveband observations of M87 by Prieto et al., most possibly comes from the synchrotron emission thermal electrons advection-dominated accretion flow (ADAF). It is possible to constrain rate near horizon if both nuclear and its polarization are produced hot plasma flow. jet power has been extensively explored, which around $8_{\rm -3}^{+7}\times 10^{42}$ erg s−1 based on analysis X-ray cavity. black hole (BH) spin can be...