A5052681729- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Particle Detector Development and Performance
- Radio Astronomy Observations and Technology
- Stellar, planetary, and galactic studies
- Particle physics theoretical and experimental studies
- Astro and Planetary Science
- Astronomy and Astrophysical Research
- Particle Accelerators and Free-Electron Lasers
- Geophysics and Gravity Measurements
- Radiation Detection and Scintillator Technologies
- Ionosphere and magnetosphere dynamics
- Cosmology and Gravitation Theories
- High-pressure geophysics and materials
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Geomagnetism and Paleomagnetism Studies
- Magnetic confinement fusion research
- Lightning and Electromagnetic Phenomena
- Precipitation Measurement and Analysis
- Nuclear Physics and Applications
Sun Yat-sen University
2016-2025
Guangdong Polytechnic of Science and Technology
2023-2024
The University of Tokyo
2023-2024
Xi'an Institute of Optics and Precision Mechanics
2022
Shanghai Astronomical Observatory
2022
National Tsing Hua University
2010-2014
University of Hong Kong
2014
Heidelberg University
2006-2011
Université Toulouse III - Paul Sabatier
2006
Centre National de la Recherche Scientifique
2006
Since the science white paper of Large High Altitude Air Shower Observatory (LHAASO) published on arXiv in 2019 [e-Print: 1905.02773 (astro-ph.HE)], LHAASO has completed transition from a project to an operational gamma-ray astronomical observatory is new generation multi-component facility located Daocheng, Sichuan province China, at altitude 4410 meters. It aims measuring with unprecedented sensitivity spectrum, composition, and anisotropy cosmic rays energy range between 10$^{12}$...
The binary system PSR B1259-63/LS 2883 consists of a 47.8 ms radio pulsar that orbits the companion Be star with period 3.4 years in highly eccentric orbit. is well sampled radio, X-rays, and TeV gamma-rays, shows orbital-phase-dependent variability all observed frequencies. Here we report on discovery >100 MeV gamma-rays from through 2010 pariastron passage. Using data collected Large Area Telescope aboard Fermi 33 days before to 75 after pariastron, detected at significance 13.6 standard...
Recent observations strongly suggest that the millisecond pulsar binary PSR J1023+0038 has developed an accretion disk since 2013 June. We present a multi-wavelength analysis of J1023+0038, which reveals 1) its gamma-rays suddenly brightened within few days in June/July and remained at high gamma-ray state for several months; 2) both UV X-ray fluxes have increased by roughly order magnitude, 3) spectral energy distribution changed significantly after sudden flux change. Time variabilities...
We present the results of a detailed investigation prompt and afterglow emission in HESS detected GRB 190829A. Swift Fermi observations phase this reveal two isolated sub-bursts or episodes, separated by quiescent phase. The energetic spectral properties first episode are stark contrast to second. episode, which has higher peak $\sim 120\:\text{keV}$ low isotropic energy 10^{50}\:\text{erg}$ is an outlier Amati correlation marginally satisfies Yonetoku correlation. However, energetically...
Context. A new X-ray Cataclysmic variable (CV) candidate exhibits distinct light-curve characteristics in the ZTF’s g , r and i bands. The paper includes optical identification multiwavelength analysis of this CV candidate. Aims. This work aims to determine if a previously identified candidate, ZTF J0112+5827, is polar system by examining its cyclotron radiation characteristics. Methods. We characterized emission J0112+5827 using ROSAT observations. gri -band light curves were obtained from...
Abstract Extremely low-mass (ELM) white dwarfs (WDs) are helium-core WDs with masses less than 0.3 M ⊙ . Short-period ELM WD binaries that exhibit ellipsoidal variations may harbor heavier companions, either massive or millisecond pulsars (MSPs). In this study, we selected ∼12,000 their candidates, and searched for ellipsoidal-like lightcurves orbital periods shorter 1 day, by using the public data from Zwicky Transient Facility. Finally, 23 such systems were found, 17 being newly...
Globular clusters (GCs) are emerging as a new class of γ-ray emitters, thanks to the data obtained from Fermi Gamma-ray Space Telescope. By now, eight GCs known emit γ-rays at energies >100 MeV. Based on stellar encounter rate GCs, we identify potential emitting out all that have not been studied in detail before. In this paper, report discovery number GCs: Liller 1, NGC 6624, and 6752, evidence emission M80, 6139, 6541, which were found within GC tidal radius. With one highest metallicities...
The Fermi Gamma-ray Space Telescope has revolutionized our knowledge of the gamma-ray pulsar population, leading to discovery almost 100 pulsars and dozens millisecond (MSPs). Although outer-gap model predicts different sites emission for radio pulsars, until now all known MSPs have been visible in radio. Here we report a "radio-quiet" emitting MSP candidate by using Fermi, Chandra, Swift, optical observations. X-ray properties source are consistent with pulsars. We also found 4.63-hr...
The extended high-energy gamma-ray (>100 MeV) emission occurred after the prompt bursts (GRBs) is usually characterized by a single power-law spectrum, which has been explained as afterglow synchrotron radiation. inverse-Compton long predicted to be able produce component well, but previous observations have not revealed such signature clearly, probably due small number of >10 GeV photons even for brightest GRBs known so far. In this Letter, we report on Fermi Large Area Telescope (LAT) >100...
PSR J2032+4127 is a radio-loud gamma-ray-emitting pulsar; it orbiting around high-mass Be type star with very long orbital period of 25-50years, and approaching periastron, which will occur in late 2017/early 2018. This system comprises young pulsar star, similar to the so-called gamma-ray binary PSR~B1259-63/LS2883. It expected therefore that shows an enhancement high-energy emission caused by interaction between wind wind/disk periastron. Ho et al. recently reported rapid increase X-ray...
We report the first hard X-ray (3-79 keV) observations of millisecond pulsar (MSP) binary PSR J1023+0038 using NuSTAR. This system has been shown transiting between a low-mass (LMXB) state and rotation-powered MSP state. The NuSTAR were taken in both LMXB source is clearly seen states up to ~79 keV. During state, 3-79 keV flux about factor 10 higher that X-rays show clear orbital modulation during faint but period not detected bright In addition, spectrum changes from flat power-law steeper...
Abstract We have performed a systematic study of the rotational, orbital, and X-ray properties millisecond pulsars (MSPs) in globular clusters (GCs) compared their nature with those MSPs Galactic field (GF). found that GC generally rotate slower than counterparts GF. Different from expectation simple recycling scenario, no evidence for correlation between orbital period rotation can be MSP binaries GCs. There is also an indication surface magnetic stronger All these suggest dynamical...
We report the discovery of pulsed {\gamma}-ray emission and X-ray from black widow millisecond pulsar PSR J2051-0827 by using data Large Area Telescope (LAT) on board Fermi Gamma-ray Space Advanced CCD Imaging Spectrometer array (ACIS-S) Chandra Observatory. Using 3 years LAT data, is clearly detected in with a signicance \sim 8{\sigma} 0.2 - 20 GeV band. The 200 MeV spectrum can be modeled simple power- law photon index 2.46 \pm 0.15. Significant (\sim 5{\sigma}) pulsations at radio period...
The binary system PSR B1259-63/LS 2883 is well sampled in radio, X-rays, and TeV gamma-rays, shows orbital phase-dependent variability these frequencies. first detection of GeV gamma-rays from the was made around 2010 periastron passage. In this Letter, we present an analysis X-ray gamma-ray data obtained by Swift/XRT, NuSTAR/FPM, Fermi/LAT, through recent passage which occurred on 2014 May 4. While not detected LAT before during passage, show that flares at a similar phase as early 2011,...
We report on evidence for orbital phase-dependence of the gamma-ray emission from PSR B1957+20 black widow system by using data Fermi Large Area Telescope. divide an cycle into two regions: a region containing inferior conjunction, and other rest cycle. show that observed spectra different regions are fitted functional forms. The spectrum conjunction can be described power-law with exponential cutoff (PLE) model, which gives best-fit model phase does not contain plus extra component above...
A glitch of a pulsar is known as sudden increase in the spin frequency and spin-down rate (frequency time derivative), it can be caused by rel\ ease stress built up solid crust star or pinned vortices superfluid interior. PSR J2021+4026 first that shows significant change gamma-ray flux pulse profile at occurred around 2011 October 16. We report results timing spectral analysis PSR~J2021+4026 using $\sim$ 8~yr Fermi-LAT data. find stayed high ($\sim 4\%$ higher than pre-glitch value) low...
We propose to develop a wide-field and ultra-high-precision photometric survey mission, temporarily named "Earth 2.0 (ET)". This mission is designed measure, for the first time, occurrence rate orbital distributions of Earth-sized planets. ET consists seven 30cm telescopes, be launched Earth-Sun's L2 point. Six these are transit telescopes with field view 500 square degrees. Staring in direction that encompasses original Kepler four continuous years, this monitoring will return tens...
The first Fermi-Large Area Telescope (LAT) catalog of sources above 10 GeV reported evidence pulsed emission 25 from 12 pulsars, including the Vela pulsar, which showed pulsation at >37 energy bands. Using 62 months Fermi-LAT data, we analyzed gamma-ray pulsar and searched for 50 GeV. Having confirmed significance in 30–50 with H test (p-value ∼10−77), extracted its pulse profile using Bayesian block algorithm compared it distribution five observed photons likelihood ratio test. Pulsation...
Abstract Supernova remnant (SNR)W28 is well known for its classic hadronic scenario, in which the TeV cosmic rays (CRs) released at early stage of this intermediate-age SNR illuminate nearby molecular clouds (MCs). Overwhelming evidence has shown that northeastern part (W28-North) already encountered MC clumps. Through broken shell W28-North, CRs with an energy down to <1 GeV may be able injected into MCs. To further verify we first analyze nine years Fermi- LAT data in/around W28...
Abstract PSR J2021+4026 is a radio-quiet gamma-ray pulsar and the first that shows state change of emission spindown rate. The was observed at 2011 October, which changes from high flux/low rate to low flux/high state. In 2014 December, recovered before over timescale few months. We report long-term evolution flux timing behavior suggests changed near 2018 February 1 entered new At change, averaged dropped (1.29 ± 0.01) × 10 −6 cts cm −2 s −1 (1.12 , similar event. has increased by ∼3% in...
We study mechanisms of multi-wavelength emissions (X-ray, GeV and TeV gamma-rays) from the gamma-ray binary LS~5039. This paper is composed two parts. In first part, we report on results observational analysis using four year data \fermi\ Large Area Telescope. Due to improvement instrumental response function increase statistics, uncertainties spectrum in $\sim$100-300 MeV bands $>10$GeV are significantly improved. The present suggests that 0.1-100GeV LS~5039 contain three different...
GeV flares from PSR B1259-63/LS 2883 were seen starting around 30 days after the two periastron passages in 2010 and 2014. The are clearly delayed compared to occurrence of X-ray TeV flux peaks during post-periastron disk crossing. While several attempts have been put forward explain this phenomenon, origin these remains a puzzle. Here we present detailed analysis observational data taken by Fermi Swift observatories over 2017 September passage. For first time, find short-lived but powerful...
Using the data from Large Area Telescope on board Fermi Gamma-ray Space Telescope, we have searched for gamma-ray pulsations direction of globular cluster M28 (NGC 6626). We report discovery a signal with frequency consistent that energetic millisecond pulsar (MSP) PSR B1821-24 in M28. A weighted H-test test statisic (TS) 28.8 is attained which corresponds to chance probability ~1e-5 (4.3-sigma detection). With phase-resolved analysis, pulsed component found contribute ~25% total observed...
The first measurements from the CIBER experiment of extragalactic background light (EBL) in near-infrared (NIR) band exhibit a higher intensity than those inferred through $\ensuremath{\gamma}$-ray observations. Recent theoretical-EBL intensities are typically consistent with very high energy (VHE) Yet, it is possible that excess NIR radiation new component EBL and not tension TeV spectra distant blazars, since hypothetical axionlike particle (ALP) may lead to reduced opacity Universe for...
We have investigated the properties of a group γ-ray-emitting globular clusters (GCs) that recently been uncovered in our Galaxy. By correlating observed γ-ray luminosity Lγ with various cluster properties, we probe origin high-energy photons from these GCs. report is positively correlated encounter rate Γc and metallicity [Fe/H], which places an intimate link between emission millisecond-pulsar population. also find tendency increases energy densities soft photon at location. Furthermore,...