A5026303095- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Stellar, planetary, and galactic studies
- High-pressure geophysics and materials
- Astro and Planetary Science
- Superconducting Materials and Applications
- Galaxies: Formation, Evolution, Phenomena
- Particle Accelerators and Free-Electron Lasers
- Astronomy and Astrophysical Research
- Particle accelerators and beam dynamics
- Laser-Plasma Interactions and Diagnostics
- Earthquake Detection and Analysis
- Astrophysics and Star Formation Studies
- Dietary Effects on Health
- Diet and metabolism studies
- Plasma Diagnostics and Applications
- Cosmology and Gravitation Theories
- Laser-induced spectroscopy and plasma
- Diet, Metabolism, and Disease
- Geophysics and Gravity Measurements
- Ionosphere and magnetosphere dynamics
- Magnetic confinement fusion research
- Astronomical Observations and Instrumentation
- Relativity and Gravitational Theory
Zhejiang Chinese Medical University
2025
Wuhan University
2021-2024
California Institute of Technology
2024
Kavli Institute for Theoretical Sciences
2022
Peking University
2022
Abstract Haystack and Owens Valley Radio Observatory observations recently revealed strong, intermittent, sinusoidal total flux-density variations that maintained their coherence between 1975 2021 in the blazar PKS 2131−021 ( z = 1.283). This was interpreted as possible evidence of a supermassive black hole binary (SMBHB). Extended through 2023 show over 47.9 yr, with an observed period P 15 GHz (1739.8 ± 17.4) days. We reject, p -value 2.09 × 10 −7 , hypothesis are due to random...
Abstract We present a detailed X-ray spectral analysis of the narrow-line Seyfert 1 galaxy I Zwicky 1, for which sequence flares were detected during long, simultaneous observation acquired with XMM-Newton and NuSTAR. determine key parameters inner accretion disk hot corona in context reflection model, successfully captures evolution flare. Using thermal Comptonization continuum we confirm that rapidly cooled from ∼200 to ∼15 keV, likely consequence strong pair production runaway disk-like...
Cyclotron line scattering features are detected in a few tens of X-ray pulsars (XRPs) and used as direct indicators strong magnetic field at the surface accreting neutron stars (NSs). In cases, cyclotron lines known to be variable with accretion luminosity XRPs. It is accepted that observed variations related geometry dynamics flow above poles NS. A positive correlation between centroid energy typical for sub-critical XRPs, where results hot spots poles. The negative was proposed specific...
In this paper, wavelet analysis is used to study spectral-timing properties of MAXI J1535-571 observed by Insight-HXMT. The low-frequency quasi-periodic oscillations (QPOs) are detected in nine observations. Based on analysis, the time intervals with QPO and non-QPO isolated separately, corresponding spectra analyzed. We find that (hereafter spectra) softer than those without hard intermediate state (HIMS). While soft (SIMS), slightly harder. disk temperature regime lower during HIMS, but...
We present a detailed study of the high mass X-ray binary Vela X-1, using observations performed by Insight-HXMT in 2019 and 2020, concentrating on timing analysis spectral studies including pulse phase-resolved spectroscopy. The cyclotron line energy is found to be at ~21-27 keV 43-50 for fundamental first harmonic, respectively. evolution parameters find that two centroid ratio E2/E1 evolved from ~2 before MJD 58900 ~1.7 after that. harmonic has no relation luminosity but shows positive...
Abstract The inclination angle of substructures in active galaxies gives insights into physical components from scales the vicinity central black hole to entire host galaxy. We use self-consistent reflection spectral model RELXILL measure inner region accretion disks with broadband (0.3–78 keV) X-ray observations, systematically studying reliability this methodology. To test capability return statistically consistent results, we analyze multiepoch joint XMM-Newton and NuSTAR data narrow-line...
Haystack and Owens Valley Radio Observatory (OVRO) observations recently revealed strong sinusoidal total flux density variations that maintained coherence between 1975 2021 in the blazar PKS 2131-021 ($z=1.283)$. This was interpreted as possible evidence of a supermassive black hole binary (SMBHB). Extended through 2023 show over 47.9~years, with an observed period $P_\textrm{15 GHz}=(1739.3 \pm 1.2) \, {\rm days}$. We reject, $p$-value = $5.3 \times 10^{-7}$, hypothesis are due to random...
Abstract Luminous accretion disks around black holes are expected to have densities of ∼10 15 −10 22 cm −3 , which high enough that plasma physics effects become important. Many these been traditionally neglected in the calculation atomic parameters, and therefore photoionization models ultimately also X-ray reflection models. In this paper, we describe updates rates used by xstar code, is turn part xillver disk model. We discuss effect adding necessary high-density corrections into code....
ABSTRACT We report the orbital X-ray variability of high-mass binary (HMXB) GX 301−2. 301−2 underwent a spin-up process in 2018–2020 with period evolving from ∼685–670 s. The energy-resolved pulse profiles pulsar at 1–60 keV varied single-peaked and sinusoidal shapes to multipeaked ones across different phases. Pulse fractions over orbit had negative correlations flux. broad-band energy spectrum can be described partially covered negative–positive cut-off power-law continuum model. Near...
In this paper, we presented a detailed timing analysis of prominent outburst 4U 0115+63 detected by \textit{Insight}-HXMT in 2017 August. The spin period the neutron star was determined to be $3.61398\pm 0.00002$ s at MJD 57978. We measured variability and extract orbital elements binary system. angle periastron evolved with rate $0.048\pm0.003$ $yr^{-1}$. light curves are folded sketch pulse profiles different energy ranges. A multi-peak structure 1-10 keV is clearly illustrated. introduced...
The inclination angle of substructures in active galaxies gives insights into physical components from scales the vicinity central black hole to entire host galaxy. We use self-consistent reflection spectral model \textsc{RELXILL} measure inner region accretion disks with broadband ($0.3-78\,\rm keV$) X-ray observations, systematically studying reliability this methodology. To test capability return statistically consistent results, we analyze multi-epoch, joint XMM-Newton and NuSTAR data...
Cyclotron resonant scattering features (CRSFs) are the absorption in X-ray spectra of strongly magnetized accretion neutron stars (NSs), which probably most reliable probe to surface magnetic fields NSs. The high mass binary GX 301--2 exhibits a very wide, variable and complicated CRSF average spectra, should be two lines based on NuStar Insight-HXMT observations. With frequent observations, we performed phase-resolved spectroscopy confirmed cyclotron with their centroid energy ratio $\sim...
ABSTRACT Cyclotron resonant scattering features (CRSFs) are the absorption in X-ray spectra of strongly magnetized accretion neutron stars (NSs), which probably most reliable probe to surface magnetic fields NSs. The high-mass binary GX 301–2 exhibits a very wide, variable, and complicated CRSF average spectra, should be two lines based on Nuclear Spectroscopic Telescope Array (NuStar) Hard Modulation (Insight-HXMT) observations. With Insight-HXMT frequent observations, we performed...
Luminous accretion disks around black holes are expected to have densities of $\sim 10^{15-22}\,$cm$^{-3}$, which high enough such that plasma physics effects become important. Many these been traditionally neglected in the calculation atomic parameters, and therefore from photoionization models, ultimately also X-ray reflection models. In this paper, we describe updates rates used by XSTAR code, is turn part XILLVER disk model. We discuss effect adding necessary density corrections into...
MAXI J1803-298 is a transient black hole candidate discovered in May of 2021 during an outburst that lasted several months. Multiple X-ray observations reveal recurring "dipping" intervals its light curves, particularly the hard/intermediate states, with typical recurrence period $\sim7\,\mathrm{hours}$. We report analysis four NuSTAR source, supplemented NICER data where available, over duration evolution covering hard, intermediate and soft states. Reflection spectroscopy reveals to be...
Using the LAMOST DR7 low-resolution spectra, we carried out a systematic study of stellar chromospheric activity in both single and binary stars. We constructed sample single-star sample, mainly using belt main sequence Hertzsprung-Russell diagram, respectively. By comparing $S$ indices between stars within each color bin, found for K type stars, binaries exhibit enhanced compared to which could be attributed increase spin rate caused by tidal synchronization or interactions magnetic fields....
Abstract Using the LAMOST DR7 low-resolution spectra, we carried out a systematic study of stellar chromospheric activity in both single and binary stars. We constructed sample single-star sample, mainly using belt main sequence Hertzsprung–Russell diagram, respectively. By comparing S indices between stars within each color bin, found for K-type stars, binaries exhibit enhanced compared to which could be attributed increase spin rate caused by tidal synchronization or interactions magnetic...
Abstract MAXI J1803-298 is a transient black hole candidate discovered in 2021 May during an outburst that lasted several months. Multiple X-ray observations reveal recurring “dipping” intervals of its light curves, particularly the hard/intermediate states, with typical recurrence period ∼7 hr. We report analysis four NuSTAR source, supplemented NICER data where available, over duration evolution covering hard, intermediate, and soft states. Reflection spectroscopy reveals to be rapidly...
Models of active galactic nuclei often invoke a close physical association between the broad-line region and accretion disk. We evaluate this theoretical expectation by investigating relationship inclination angle BLR ($\theta_\mathrm{BLR}$) inner disk ($\theta_\mathrm{disk}$). For sample eight that have published values $\theta_\mathrm{BLR}$ estimated from dynamical modeling based on velocity-resolved reverberation mapping experiments, we analyze high-quality, joint XMM-Newton NuSTAR X-ray...