A5003425206- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Astronomical Observations and Instrumentation
- Particle Detector Development and Performance
- High-pressure geophysics and materials
- Mechanics and Biomechanics Studies
- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Geophysics and Gravity Measurements
- Astronomy and Astrophysical Research
- Atmospheric Ozone and Climate
- Radio Astronomy Observations and Technology
- Advanced Frequency and Time Standards
- Statistical and numerical algorithms
- Stellar, planetary, and galactic studies
- Earthquake Detection and Analysis
- Atmospheric aerosols and clouds
- CCD and CMOS Imaging Sensors
- Magnetic confinement fusion research
- Particle accelerators and beam dynamics
- Geomagnetism and Paleomagnetism Studies
- Radiation Therapy and Dosimetry
- Calibration and Measurement Techniques
University of Tübingen
2023-2024
Max Planck Institute for Astrophysics
2024
Institute of High Energy Physics
2017-2023
Chinese Academy of Sciences
2017-2023
University of Chinese Academy of Sciences
2017-2023
We present the X-ray timing results of new black hole candidate (BHC) MAXI J1535-571 during its 2017 outburst from Hard Modulation Telescope (\emph{Insight}-HXMT) observations taken September 6 to 23. Following definitions given by \citet{Belloni2010}, we find that source exhibits state transitions Low/Hard (LHS) Intermediate (HIMS) and eventually Soft (SIMS). Quasi-periodic oscillations (QPOs) are found in intermediate states, which suggest different types QPOs. With large effective area...
Abstract The milestone discovery of GW170817-GRB 170817A-AT 2017gfo has shown that gravitational waves (GWs) could be produced during the merger a neutron star–neutron star/black hole and in electromagnetic (EM) waves, gamma-ray burst (GRB) kilonova (KN) are generated sequence after merger. Observationally, however, EM properties before phase still unclear. Here we report peculiar precursor KN-associated long-duration GRB 211211A, providing evidence This lasts ∼0.2 s, waiting time between...
Abstract Fast radio bursts (FRBs) are short pulses observed in band from cosmological distances, some of which emit repeating bursts. The physical origins these mysterious events have been subject to wide speculations and heated debates. One class models invoke soft gamma-ray repeaters (SGRs), or magnetars, as the sources FRBs. Magnetars rotating neutron stars with extremely strong magnetic field can sporadically X-ray (keV) (sub-MeV) duration 102 s 102 s. However, even though bright no...
The origin(s) and mechanism(s) of fast radio bursts (FRBs), which are short pulses from cosmological distances, have remained a major puzzle since their discovery. We report strong Quasi-Periodic Oscillation(QPO) 40 Hz in the X-ray burst magnetar SGR J1935+2154 associated with FRB 200428, significantly detected Hard Modulation Telescope (Insight-HXMT) also hinted by Konus-Wind data. QPOs only been rarely detected; our 3.4 sigma (p-value is 2.9e-4) detection QPO reported here reveals...
ABSTRACT High time resolution and accuracy are of critical importance in the studies timing analysis delay localization gamma-ray bursts (GRBs), soft repeaters (SGRs) pulsars. The Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) consisting two micro-satellites, GECAM-A GECAM-B, launched on 2020 December 10, is aimed at monitoring locating X-ray GRBs all over sky. To achieve its scientific goals, GECAM designed to have highest (0.1 $\mu {\rm s}$) among GRB...
ABSTRACT We present a comprehensive timing analysis on the Be/X-ray binary pulsar RX J0440.9+4431 using observations from NICER and Insight-HXMT during 2022–2023 outburst. The power density spectrum (PDS) of exhibits typical aperiodic variability in X-ray flux across wide frequency range. During supercritical accretion state, we detect quasi-periodic oscillations (QPOs) at 0.2–0.5 Hz light curves five pulses for J0440.9+4431. observed QPOs manifest flares, while flares appear peaks pulse...
Abstract Using data from the Neutron star Interior Composition ExploreR observatory, we identified a permanent spin frequency decrease of Δ ν = −(1.04 ± 0.07) × 10 −7 Hz around MJD 60132 in rotation-powered pulsar PSR B0540-69, which exhibits periodic signal at ∼ 19.6 Hz. This points to an antiglitch event, sudden pulsar’s rotational without any major alteration pulse profile or significant increase pulsed flux. Additionally, no burst activity was observed association with antiglitch. To...
We report on analysis of observations the bright transient X-ray pulsar \src obtained during its 2017-2018 giant outburst with Insight-HXMT, \emph{NuSTAR}, and \textit{Swift} observatories. focus discovery a sharp state transition timing spectral properties source at super-Eddington accretion rates, which we associate disk to radiation pressure dominated (RPD) state, first ever directly observed for magnetized neutron star. This occurs slightly higher luminosity compared already reported...
Magnetars are neutron stars with extreme magnetic field and sometimes manifest as soft gamma-ray repeaters (SGRs). SGR J1935+2154 is one of the most prolific bursters first confirmed source fast radio burst (i.e. FRB 200428). Encouraged by discovery X-ray counterpart FRB, Insight-Hard Modulation Telescope (Insight-HXMT) implemented a dedicated 33-day long ToO observation since April 28, 2020. With HE, ME, LE telescopes, Insight-HXMT provides thorough monitoring activity evolution J1935+2154,...
Abstract The minimum variation timescale (MVT) of soft gamma-ray repeaters can be an important probe to estimate the emission region in pulsar-like models, as well Lorentz factor and radius possible relativistic jet burst (GRB)–like thus revealing their progenitors physical mechanisms. In this work, we systematically study MVTs hundreds X-ray bursts (XRBs) from SGR J1935+2154 observed by Insight-HXMT, GECAM, Fermi/Gamma-ray Burst Monitor 2014 July 2022 January through Bayesian block...
In this work, we report the in-orbit demonstration of X-ray pulsar navigation with Insight-Hard Modulation Telescope (Insight-HXMT), which was launched on Jun. 15th, 2017. The new method 'Significance Enhancement Pulse-profile Orbit-dynamics' (SEPO) is adopted to determine orbit observations only one pulsar. test, Crab chosen and observed by Insight-HXMT from Aug. 31th Sept. 5th in Using 5-day-long observation data, determined successfully three telescopes onboard - High Energy (HE), Medium...
Abstract Gamma-ray bursts (GRBs) have been identified as one of the most promising sources for Lorentz invariance violation (LIV) studies due to their cosmological distance and energetic emission in wide energy bands. However, arrival-time difference GRB photons among different bands is affected not only by LIV effect but also poorly known intrinsic spectral lags. In previous studies, assumptions lag be made which could introduce systematic errors. this paper, we used a sample 46 short GRBs...
ABSTRACT Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) is a dedicated mission, launched in December 2020, for gamma-ray transients, including bursts (GRBs) and soft gamma repeater (SGR) the multimessenger multiwavelength astronomy era. Since GECAM consists of two independent spacecrafts (or say instruments), framework data analysis multiple distinctive from that only one spacecraft, which case most GRB missions, we developed pipeline called Energetic...
ABSTRACT Spectral lag of the low-energy photons with respect to high-energy ones is a common astrophysical phenomenon (such as gamma-ray bursts and Crab Pulsar) may serve key probe underlying radiation mechanism. However, spectral in keV range magnetar has not been systematically studied yet. In this work, we perform detailed analysis Li et al.’s Cross-Correlation Function (Li-CCF) method for SGR J1935+2154 observed by Insight-Hard X-ray Modulation Telescope (HXMT), Gravitational Wave...
The black hole X-ray binary GRS 1915+105 was bright for 26 years since its discovery and is well-known disk instabilities, quasi-periodic oscillations, wind signatures. We report a long-term spectral-timing tracing of this source from mid-2017 until the onset "obscured state", based on complete data Neutron Star Interior Composition Explorer (NICER) Insight--Hard Modulation Telescope (HXMT), whose hard coverage decisively informs modeling at lower energies. In soft state predating 2018, we...
We report the results of a X-ray spectral and timing analysis high mass binary EXO 2030+375 during 2021 type-II outburst based on observations. confirm that pulsations can be detected in energy band 1--150,keV. The pulse profile shows both luminosity dependence variability. observed transitions shape rising decaying phase outburst. fraction (PF) exhibits an anti-correlation with non-monotonic dependence, possible dip near 30,keV peak. hardness-intensity diagrams (7--10,keV/4--7,keV) suggests...
We report the X-ray spectral and timing analysis of high mass binary EXO 2030+375 during 2021 type-II outburst based on Insight-HXMT observations. Pulsations can be detected in energy band 1-150 keV. The pulse profile shows luminosity dependence variability. observed transitions shape rising decaying phase outburst. fraction exhibits an anti-correlation with a non-monotonic dependence, possible dip near 30 keV peak. hardness-intensity diagrams (7-10 keV/4-7 keV) suggest state early late...
Corona cooling was detected previously from stacking a series of short type-I bursts occurred during the low/had state atoll outburst. Type-I are hence regarded as sharp probe to our better understanding on basic property corona. The launch first Chinese X-ray satellite Insight-HXMT has large detection area at hard X-rays which provide almost unique chance move further in this research field. We report corona by single burst showing up {\bf flare} 4U 1636-536. This duration $\sim$13 seconds...
No robust detection of prompt electromagnetic counterparts to fast radio bursts (FRBs) has yet been obtained, in spite several multi-wavelength searches carried out so far. Specifically, X/gamma-ray are predicted by some models. We planned on searching for gamma-ray the Insight-Hard X-ray Modulation Telescope (Insight-HXMT) data, taking advantage unique combination large effective area keV-MeV energy range and sub-ms time resolution. selected 39 FRBs that were promptly visible from...
Abstract We study the spectral evolution of black hole candidate EXO 1846−031 during its 2019 outburst, in 1–150 keV band, with Hard X-ray Modulation Telescope. The continuum spectrum is well modeled an absorbed disk-blackbody plus cutoff power law, hard, intermediate, and soft states. In addition, we detect ≈6.6 Fe emission line hard intermediate state. Throughout states, fitted inner disk radius remains almost constant; suggest that it has settled at innermost stable circular orbit (ISCO)....