A5020226724- Gamma-ray bursts and supernovae
- Pulsars and Gravitational Waves Research
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Astro and Planetary Science
- Stellar, planetary, and galactic studies
- Dark Matter and Cosmic Phenomena
- Astronomy and Astrophysical Research
- Radio Astronomy Observations and Technology
- Particle Detector Development and Performance
- Astronomical Observations and Instrumentation
- Cosmology and Gravitation Theories
- Particle physics theoretical and experimental studies
- Geophysics and Gravity Measurements
- Galaxies: Formation, Evolution, Phenomena
- Solar and Space Plasma Dynamics
- Neutrino Physics Research
- Astrophysics and Star Formation Studies
- Black Holes and Theoretical Physics
- Radiation Detection and Scintillator Technologies
- SAS software applications and methods
- High-pressure geophysics and materials
- Particle Accelerators and Free-Electron Lasers
- Chemical Thermodynamics and Molecular Structure
- Nuclear Physics and Applications
Guangxi University
2016-2025
Chinese Academy of Sciences
2001-2024
Yunnan Observatories
2000-2024
Purple Mountain Observatory
2016-2023
Shanghai Astronomical Observatory
2021-2023
Campbell Collaboration
2023
Nanjing University
2003-2020
University of Nevada, Las Vegas
2007-2020
Guangxi University of Chinese Medicine
2020
Yunnan University
2002-2020
(Abridged) The two high-redshift gamma-ray bursts, GRB 080913 at z=6.7 and 090423 z=8.3, recently detected by Swift appear as intrinsically short, hard GRBs. They could have been recognized BATSE short/hard GRBs should they occurred z <= 1. We perform a more thorough investigation on physically distinct types (Type I/II) of cosmological their observational characteristics. reiterate the definitions Type I/II review criteria physical motivations. Contrary to traditional approach assigning...
We present a systematic temporal and spectral study of all Swift-X-ray Telescope observations gamma-ray burst (GRB) afterglows discovered between 2005 January 2007 December. After constructing fitting light curves spectra to power-law models, we classify the components each afterglow in terms canonical X-ray test them against closure relations forward shock models for variety parameter combinations. The are used identify potential jet breaks with characteristics including uniform model...
The discovery of the first electromagnetic counterpart to a gravitational wave signal has generated follow-up observations by over 50 facilities world-wide, ushering in new era multi-messenger astronomy. In this paper, we present event GW170817 and its SSS17a/DLT17ck (IAU label AT2017gfo) 14 Australian telescopes partner observatories as part Australian-based Australian-led research programs. We report early- late-time multi-wavelength observations, including optical imaging spectroscopy,...
We present a multi-variable regression analysis to several observable quantities for sample of 15 gamma-ray bursts (GRBs). The observables used in the includes isotropic energy (E_{gamma,iso}), peak nu F_nu spectrum rest frame (E_p'), and break time optical afterglow light curves(t_b'). A strong dependence E_{gamma, iso on E_p' t_b' is derived. also extend energies X-ray bands, respectively, find that they are essentially not correlated with t_b'. Regarding iso(E_p', t_b') relationship as...
We systematically analyze the prompt emission and early afterglow data of a sample 31 GRBs detected by {\em Swift} before September 2005, estimate GRB radiative efficiency. BAT's narrow band inhibits precise determination spectral parameters, we have developed method to these parameters with hardness ratio information. The shallow decay component commonly existing in X-ray afterglows, if interpreted as continuous energy injection external shock, suggests that efficiency previously derived...
The onset of GRB afterglow is characterized by a smooth bump in the early lightcurve. We make an extensive search for such feature. Twenty optically selected GRBs and 12 X-ray are found, among which 17 2 X-ray-selected have redshift measurements. fit lightcurves with broken power-law measure temporal characteristic timescales bumps at FWHM. Strong mutual correlations these dimmer broader tends to peak later time. ratio rising decaying almost universal bursts, but time varies from 0.3~1....
The absence of a supernova accompanying the nearby long GRB 060614 poses great puzzle about progenitor this event and challenges current classification scheme. This burst displays short-hard emission episode followed by extended soft with strong spectral evolution. Noticing that has an isotropic gamma-ray energy only ~8 times 050724, good candidate merger-type short GRBs, we generate "pseudo"burst is less energetic than based on properties Ep ∝ E (Amati) relation. We find pseudoburst would...
Swift/BAT has detected ~ 200 long-duration GRBs, with redshift measurements for ~50 of them. We derive the luminosity function (Phi^{HL}) and local event rate (rho_0^{HL}) conventional high (HL) GRBs by using z-known Swift GRBs. Our results are generally consistent that derived from CGRO/BATSE data. However, fact a low (LL) GRB, GRB 060218, at z=0.033 within 2 year operation, together previous detection nearby 980425, suggests much higher these LL-GRBs. explore possibility LL-GRBs as...
An Eγ, jet ∝ E relationship with a small scatter for current gamma-ray burst (GRB) data was recently reported, where is the beaming-corrected energy and νFν peak in local observer frame. By considering this sample of 12 GRBs known redshift, energy, break time afterglow light curves, we constrain mass density universe nature dark energy. We find that ΩM = 0.35 (at 1 σ confidence level) flat cosmological constant, w parameter an assumed static equation state -0.84 (1 σ). Our results are...
We present a detailed analysis of Swift multi-wavelength observations GRB 070110 and its remarkable afterglow. The early X-ray light curve, interpreted as the tail prompt emission, displays spectral evolution already seen in other gamma-ray bursts. optical afterglow shows shallow decay up to ~2 d after burst, which is not consistent with standard models. most intriguing feature very steep flux at ~20 ks ending an apparent plateau. abrupt drop curve rules out external shock origin plateau...
We report on the detection by Swift of GRB 080913, and subsequent optical/near-infrared follow-up observations GROND, which led to discovery its optical/NIR afterglow recognition high-z nature via a spectral break between i' z' bands. Spectroscopy obtained at ESO-VLT revealed continuum extending down λ = 9400 Å, zero flux for 7500 Å<λ < we interpret as onset Gunn–Peterson trough z 6.695± 0.025 (95.5% confidence level), making 080913 highest-redshift gamma-ray burst (GRB) date, more distant...
We present a systematic analysis of the spectral and temporal properties 17 gamma-ray bursts (GRBs) codetected by Gamma-ray Burst Monitor (GBM) Large Area Telescope (LAT) onboard Fermi satellite in 2010 May. performed time-resolved all bursts, with finest resolution allowed statistics, to reduce smearing different components. found that spectra 14 out GRBs are best modeled classical "Band" function over entire range, which may suggest common origin for emissions detected LAT GBM. GRB 090902B...
Double neutron star (DNS) merger events are promosing candidates of short Gamma-ray Burst (sGRB) progenitors as well high-frequecy gravitational wave (GW) emitters. On August 17, 2017, such a coinciding event was detected by both the LIGO-Virgo detector network GW170817 and Gamma-Ray Monitor on board NASA's {\it Fermi} Space Telescope GRB 170817A. Here we show that fluence spectral peak energy this sGRB fall into lower portion distributions known sGRBs. Its isotropic luminosity is abnormally...
BL Lac objects are the best candidates to study jet properties since their spectral energy distributions (SEDs) less contaminated by emission from accretion disk and external Compton processes. We compile broadband SEDs observed with Fermi/LAT other instruments literature for 24 TeV objects. Two SEDs, which identified as a low or high state according its flux density at 1 TeV, available each of 10 These can be explained well synchrotron+synchrotron-self-Compton model. constrain magnetic...
A hyperaccreting stellar-mass black hole has been long speculated as the best candidate for central engine of gamma-ray bursts (GRBs). Recent rich observations GRBs by space missions such Swift and Fermi pose new constraints on GRB models. In this paper, we study baryon-loading processes a jet launched from engine. We consider relativistic powered -annihilation or Blandford–Znajek (BZ) mechanism. baryon loading neutrino-driven wind neutrino-cooling-dominated accretion flow. For magnetically...
Well-sampled optical lightcurves of 146 gamma-ray bursts (GRBs) are compiled from the literature. By empirical fitting we identify eight possible emission components and summarize results in a "synthetic" lightcurve. Both flare early shallow-decay likely related to long-term central engine activities. We focus on their statistical properties this paper. Twenty-four flares obtained 19 GRBs. The isotropic R-band energy is smaller than 1% $E_{\gamma, \rm iso}$. relation between luminosities...
We continue our systematic statistical study of various components gamma-ray burst (GRB) optical light curves. decompose the early onset bump and late re-brightening with empirical fits analyze their properties. Among 146 GRBs that have well-sampled curves, bumps are observed in 38 26 GRBs, respectively. It is found typical rising decaying slopes for both ∼1.5 ∼ − 1.15, No X-ray band detected to be associated bumps, while an half bumps. The peak luminosity anti-correlated time Both Lp...
X-ray flares are generally supposed to be produced by the later central engine activities, and may share similar physical origin with prompt emission of gamma-ray bursts (GRBs). In this paper, we have analyzed all significant from GRBs observed {\em Swift} April 2005 March 2015. The catalog contains 468 bright flares, including 200 redshifts. We obtain fitting results such as start time, peak duration, flux, fluence, luminosity, mean luminosity. luminosity decreases following a power-law...
Abstract We study the influence of parameter $$\alpha $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>α</mml:mi></mml:math> on optical features Schwarzschild-MOG black holes with different thin accretions in scalar-tensor-vector gravity. As increases from 0, radii event horizon, photon sphere, and observed shadow increase comparison Schwarzschild hole. constrain experimental data reported by Event Horizon Telescope Collaboration for M87 $$^{*}$$...
The feature of the observed shadows and rings an astrophysical black hole (BH) may depend on its accretion flows magnetic charge. We find that shadow radii critical impact parameters Hayward BH are decreased with increase Comparing Schwarzschild using ray-tracing method, we show density deflection lights charge, singularity does not affect generation shadow. Based three optically thin flow models, two-dimensional in celestial coordinates derived. It is found photon ring luminosities a...
ABSTRACT The discovery of the radioactively powered kilonova AT2017gfo, associated with short-duration gamma-ray burst GRB 170817A and gravitational wave source GW170817, has provided first direct evidence supporting binary neutron star mergers as crucial astrophysical sites for synthesis heavy elements beyond iron through r-process nucleosysthesis in universe. However, recent identification kilonovae following long-duration bursts, such 211211A 230307A, sparked discussions about potential...