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First Digit Distributions of Gamma-Ray Bursts
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作者 Hou-Yu Lai Jun-Jie Wei 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第5期70-75,共6页
The occurrence of the first significant digits from real world sources is usually not equally distributed,but is consistent with a logarithmic distribution instead,known as Benford’s law.In this work,we perform a com... The occurrence of the first significant digits from real world sources is usually not equally distributed,but is consistent with a logarithmic distribution instead,known as Benford’s law.In this work,we perform a comprehensive investigation on the first digit distributions of the duration,fluence,and energy flux of gamma-ray bursts (GRBs) for the first time.For a complete GRB sample detected by the Fermi satellite,we find that the first digits of the duration and fluence adhere to Benford’s law.However,the energy flux shows a significant departure from this law,which may be due to the fact that a considerable part of the energy flux measurements is restricted by lack of spectral information.Based on the conventional duration classification scheme,we also check if the durations and fluences of long and short GRBs (with duration T_(90)>2 s and T_(90)≤2 s,respectively) obey Benford’s law.We find that the fluences of both long and short GRBs still agree with the Benford distribution,but their durations do not follow Benford’s law.Our results hint that the long–short GRB classification scheme does not directly represent the intrinsic physical classification scheme. 展开更多
关键词 (stars:)gamma-ray burst general-methods statistical-astronomical databases MISCELLANEOUS
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Time-resolved Spectral Properties of Fermi-GBM Bright Long Gamma-Ray Bursts
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作者 Wan-Kai Wang Wei Xie +4 位作者 Zhi-Fu Gao Shuo Xiao Ai-Jun Dong Bin Zhang Qi-Jun Zhi 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第2期58-73,共16页
The prompt emission mechanism of gamma-ray bursts(GRBs)is still unclear,and the time-resolved spectral analysis of GRBs is a powerful tool for studying their underlying physical processes.We performed a detailed time-... The prompt emission mechanism of gamma-ray bursts(GRBs)is still unclear,and the time-resolved spectral analysis of GRBs is a powerful tool for studying their underlying physical processes.We performed a detailed time-resolved spectral analysis of 78 bright long GRB samples detected by Fermi/Gamma-ray Burst Monitor.A total of 1490 spectra were obtained and their properties were studied using a typical Band-shape model.First,the parameter distributions of the time-resolved spectrum are given as follows:the low-energy spectral indexα~-0.72,high-energy spectral indexβ~2.42,the peak energy E_(p)~221.69 keV,and the energy flux F~7.49×10^(-6)erg cm^(-2)s^(-1).More than 80%of the bursts exhibit the hardest low-energy spectral indexα_(max),exceeding the synchrotron limit(-2/3).Second,the evolution patterns of a and E_(p)were statistically analyzed.The results show that for multi-pulse GRBs the intensity-tracking pattern is more common than the hard-to-soft pattern in the evolution of both E_(p)andα.The hard-to-soft pattern is generally shown in single-pulse GRBs or in the initial pulse of multi-pulse GRBs.Finally,we found a significant positive correlation between F and E_(p),with half of the samples exhibiting a positive correlation between F andα.We discussed the spectral evolution of different radiation models.The diversity of spectral evolution patterns indicates that there may be more than one radiation mechanism occurring in the GRB radiation process,including photo spheric radiation and synchrotron radiation.However,it may also involve only one radiation mechanism,but more complicated physical details need to be considered. 展开更多
关键词 (stars:)gamma-ray burst general-methods statistical-methods data analysis
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Prolonged intermittent theta burst stimulation restores the balance between A_(2A)R-and A_(1)R-mediated adenosine signaling in the 6-hydroxidopamine model of Parkinson's disease
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作者 Milica Zeljkovic Jovanovic Jelena Stanojevic +4 位作者 Ivana Stevanovic Milica Ninkovic Tihomir V.Ilic Nadezda Nedeljkovic Milorad Dragic 《Neural Regeneration Research》 SCIE CAS 2025年第7期2053-2067,共15页
An imbalance in adenosine-mediated signaling,particularly the increased A_(2A)R-mediated signaling,plays a role in the pathogenesis of Parkinson's disease.Existing therapeutic approaches fail to alter disease prog... An imbalance in adenosine-mediated signaling,particularly the increased A_(2A)R-mediated signaling,plays a role in the pathogenesis of Parkinson's disease.Existing therapeutic approaches fail to alter disease progression,demonstrating the need for novel approaches in PD.Repetitive transcranial magnetic stimulation is a non-invasive approach that has been shown to improve motor and non-motor symptoms of Parkinson's disease.However,the underlying mechanisms of the beneficial effects of repetitive transcranial magnetic stimulation remain unknown.The purpose of this study is to investigate the extent to which the beneficial effects of prolonged intermittent theta burst stimulation in the 6-hydroxydopamine model of experimental parkinsonism are based on modulation of adenosine-mediated signaling.Animals with unilateral 6-hydroxydopamine lesions underwent intermittent theta burst stimulation for 3 weeks and were tested for motor skills using the Rotarod test.Immunoblot,quantitative reverse transcription polymerase chain reaction,immunohistochemistry,and biochemical analysis of components of adenosine-mediated signaling were performed on the synaptosomal fraction of the lesioned caudate putamen.Prolonged intermittent theta burst stimulation improved motor symptoms in 6-hydroxydopamine-lesioned animals.A 6-hydroxydopamine lesion resulted in progressive loss of dopaminergic neurons in the caudate putamen.Treatment with intermittent theta burst stimulation began 7 days after the lesion,coinciding with the onset of motor symptoms.After treatment with prolonged intermittent theta burst stimulation,complete motor recovery was observed.This improvement was accompanied by downregulation of the e N/CD73-A_(2A)R pathway and a return to physiological levels of A_(1)R-adenosine deaminase 1 after 3 weeks of intermittent theta burst stimulation.Our results demonstrated that 6-hydroxydopamine-induced degeneration reduced the expression of A_(1)R and elevated the expression of A_(2A)R.Intermittent theta burst stimulation reversed these effects by restoring the abundances of A_(1)R and A_(2A)R to control levels.The shift in ARs expression likely restored the balance between dopamine-adenosine signaling,ultimately leading to the recovery of motor control. 展开更多
关键词 A_(1)R A_(2A)R adenosine receptors ADENOSINE ecto-5′-nucleotidase intermittent theta burst stimulation non-invasive brain stimulation Parkinson's disease purinergic signalling
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Gamma-Rays in Association with the Rocket-Triggered Lightning Caused by Neutron Bursts
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作者 Gerson S. Paiva Carlton A. Taft +1 位作者 Marcos C. Carvalho Nelson C. Furtado 《Atmospheric and Climate Sciences》 2013年第4期459-464,共6页
In this work, it shows that nuclear reactions in lightning channel, which are produced by the deuterium-deuterium (D-D) and deuterium-tritium (D-T) nuclear reactions, represent a plausible mechanism for gamma-ray burs... In this work, it shows that nuclear reactions in lightning channel, which are produced by the deuterium-deuterium (D-D) and deuterium-tritium (D-T) nuclear reactions, represent a plausible mechanism for gamma-ray bursts observed at ground. Gamma-ray emissions from lightning can be explained by neutron inelastic scattering in the air. Neutrons (produced in lightning channel) will delay a definitive time (~33 ms) to cover the atmosphere before hitting a molecule and producing gamma rays, which is somewhat longer than the gamma-ray time delay (~20 ms) observed at ground. 展开更多
关键词 GAMMA-RAY DEUTERIUM Rocket-Triggered LIGHTNING Nuclear Fusion
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Relative Spectral Lag: a New Redshift Indicator of Gamma-ray Bursts 被引量:5
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作者 Zhi-Bin Zhang Jia-Gan Deng +1 位作者 Rui-Jing Lu Hai-Feng Gao 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2006年第3期312-322,共11页
Using 64 ms count data of long gamma-ray bursts (T90 〉 2.6 s), we analyze the quantity named relative spectral lag (RSL), T31/FWHM(1). We investigated in detail all the correlations between the RSL and other pa... Using 64 ms count data of long gamma-ray bursts (T90 〉 2.6 s), we analyze the quantity named relative spectral lag (RSL), T31/FWHM(1). We investigated in detail all the correlations between the RSL and other parameters for a sample of nine long bursts, using the general cross-correlation technique that includes the lag between two different energy bands. We conclude that the distribution of RSLs is normal and has a mean value of 0.1; that the RSLs are weakly correlated with the FWHM, the asymmetry, peak flux (Fp), peak energy (Ep) and spectral indexes (α and β), while they are uncorrelated with τ31, the hardness- ratio (HR31) and the peak time (tm). Our important discovery is that redshift (z) and peak luminosity (Lp) are strongly correlated with the RSL, which can be measured easily and directly, making the RSL a good redshift and peak luminosity indicator. 展开更多
关键词 gamma-rays: bursts - methods: data analysis
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Delayed onset and fast rise of prompt optical-UV emission from gamma-ray bursts in molecular clouds
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作者 Xiao-Hong Cui Zhuo Li Li-Ping Xin 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2013年第1期57-70,共14页
Observations imply that long "y-ray bursts (GRBs) originate from the explo- sions of massive stars, therefore they may occur in the molecular clouds where their progenitors were born. We show that the prompt optica... Observations imply that long "y-ray bursts (GRBs) originate from the explo- sions of massive stars, therefore they may occur in the molecular clouds where their progenitors were born. We show that the prompt optical-UV emission from GRBs may be delayed due to dust extinction, which can explain the observed optical delayed on- set and fast rise in GRB 080319B well. The density and the size of the molecular cloud around GRB 080319B are roughly constrained to be ~ 103 cm-z and ~ 8 pc, respectively. We also investigate other GRBs with prompt optical-UV data, and find similar values of the densities and sizes of the local molecular clouds. Future obser- vations of prompt optical-UV emission from GRBs on a timescale of subseconds, e.g. by UFFO-Pathfinder and SVOM-GWAC, will provide more evidence and probes of the local environments of GRBs. 展开更多
关键词 radiation mechanisms: non-thermal -- gamma-rays: bursts -- dust: ex-tinction
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Coal bursts that occur during development: A rock mechanics enigma 被引量:10
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作者 Christopher Mark 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2018年第1期35-42,共8页
Coal bursts are typically associated with highly stressed coal.Most bursts occur during retreat mining(longwall mining or pillar recovery) in highly stressed locations like the tailgate corner of the longwall panel.Ot... Coal bursts are typically associated with highly stressed coal.Most bursts occur during retreat mining(longwall mining or pillar recovery) in highly stressed locations like the tailgate corner of the longwall panel.Others are associated with multiple seam interactions.However, a small but significant percentage of coal bursts have occurred during development or in outby locations unaffected by active mining.Most development bursts have been relatively small, but some have been highly destructive.No theory of coal bursts can be complete if it does not account for this type of event.This paper focusses on the development mining coal burst experience in the US, putting it into the context of the entire US coal burst database.The first documented development coal burst occurred almost exactly 100 years ago during slope drivage at the Sunnyside Mine in Utah.Sunnyside subsequently had a long history of bursts, mainly during retreat mining but also during development.Several Colorado mines have also experienced multiple development bursts.Many, but by no means all, of the development bursts in these western US coalfields have been associated with known faults.In the Central Appalachian coalfields, most development bursts have occurred in multiple seam situations.In some of these cases, however, there was no retreat mining in either seam.The paper closes with some lessons from this history, with implications for preventing such events in the future. 展开更多
关键词 COAL UNDERGROUND Ground control bursts Multiple SEAM
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Gamma-Ray Bursts in the Swift Era 被引量:11
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作者 Bing Zhang 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2007年第1期1-50,共50页
Since the successful launch of NASA's dedicated gamma-ray burst (GRB) mission, Swift, the study of cosmological GRBs has entered a new era. Here I review the rapid observational and theoretical progress in this dyn... Since the successful launch of NASA's dedicated gamma-ray burst (GRB) mission, Swift, the study of cosmological GRBs has entered a new era. Here I review the rapid observational and theoretical progress in this dynamical research field during the first two-year of the Swift mission, focusing on how observational breakthroughs have revolutionized our understanding of the physical origins of GRBs. Besides summarizing how Swift helps to solve some pre-Swift mysteries, I also list some outstanding problems raised by the Swift observations. An outlook of GRB science in the future, especially in the GLAST era, is briefly discussed. 展开更多
关键词 gamma-rays bursts
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A review of energy associated with coal bursts 被引量:8
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作者 Winton J.Gale 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2018年第5期755-761,共7页
A coal burst is defined as a rapid expulsion of coal(and potentially gas) from the boundary of the roadway. Rock and coal fractures together with micro seismic vibration is a common occurrence during mining, however, ... A coal burst is defined as a rapid expulsion of coal(and potentially gas) from the boundary of the roadway. Rock and coal fractures together with micro seismic vibration is a common occurrence during mining, however, it is very uncommon for coal and rock to be propelled into the roadway. Irrespective, such occurrences do occur and appear to require significantly more energy than is available from strain energy release during coal cutting. The sources of energy which can contribute to the propulsion of coal from the face or ribs are typically strain energy from the surrounding ground, seismic energy from a rapid rupture of the ground in the vicinity, or rapid expansion of gas from within the burst source area. The aim of this paper is to briefly review the bursts which may be related to strain energy, seismic energy and gas energy. 展开更多
关键词 COAL burst STRAIN ENERGY Gas ENERGY SEISMIC ENERGY PILLAR stability
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Relationships between Relative Spectral Lags and Relative Widths of Gamma-ray Bursts 被引量:3
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作者 Zhao-Yang Peng Rui-Jing Lu +1 位作者 Yi-Ping Qin Bin-Bin Zhang 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2007年第3期428-434,共7页
The phenomenon of gamma-ray burst (GRB) spectral lags is very common, but a definitive explanation has not yet been given. From a sample of 82 GRB pulses we find that the spectral lags are correlated with the pulse ... The phenomenon of gamma-ray burst (GRB) spectral lags is very common, but a definitive explanation has not yet been given. From a sample of 82 GRB pulses we find that the spectral lags are correlated with the pulse widths, however, there is no correlation between the relative spectral lags and the relative pulse widths. We suspect that the correlations between spectral lags and pulse widths might be caused by the Lorentz factor of the GRBs concerned. Our analysis on the relative quantities suggests that the intrinsic spectral lag might reflect other aspect of pulses than the aspect associated with the dynamical time of shocks or that associated with the time delay due to the curvature effect. 展开更多
关键词 gamma-rays bursts - methods statistical - gamma-rays theory
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Coal bursts in the deep longwall mines of the United States 被引量:24
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作者 Christopher Mark 《International Journal of Coal Science & Technology》 EI 2016年第1期1-9,共9页
Coal bursts involve the sudden, violent ejection of coal or rock into the mine workings. They are a particular hazard because they typically occur without warning. During the past 2 years three US coal miners were kil... Coal bursts involve the sudden, violent ejection of coal or rock into the mine workings. They are a particular hazard because they typically occur without warning. During the past 2 years three US coal miners were killed in two coal bursts, following a 6-year period during which there were zero burst fatalities. This paper puts the US experience in the context of worldwide research into coal bursts. It focuses on two major longwall mining coalfields which have struggled with bursts for decades. The Utah experience displays many of the "classic" burst characteristics, including deep cover, strong roof and floor rock, and a direct association between bursts and mining activity. In Colorado, the longwalls of the North Fork Valley (NFV) also work at great depth, but their roof and floor strengths are moderate, and most bursts have occurred during entry development or in headgates, bleeders, or other outby locations. The NFV bursts also are more likely to be associated with geologic structures and large magnitude seismic events. The paper provides a detailed case history to illustrate the experience in each of these coalfields. The paper closes with a brief discussion of how US longwalls have managed the burst risk. 展开更多
关键词 Underground mining COAL burst LONGWALL Strata control
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Convective Bursts Episode of the Rapidly Intensified Typhoon Mujigae(2015) 被引量:2
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作者 Shuai YANG Xiba TANG +4 位作者 Shuixin ZHONG Bin CHEN Yushu ZHOU Shouting GAO Chengxin WANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2019年第5期541-556,共16页
Convective burst(CB) characteristics at distinct stages of a rapidly intensified Typhoon Mujigae(2015), are investigated based on a 72-h simulation. The spatial features show that almost all CB elements develop in the... Convective burst(CB) characteristics at distinct stages of a rapidly intensified Typhoon Mujigae(2015), are investigated based on a 72-h simulation. The spatial features show that almost all CB elements develop in the eyewall. The number of CBs in the inner-core region within a 100 km radius—which account for a large proportion of the total CBs, with a sharp increase about 6 h before the onset of rapid intensification(RI)—provides some indication of the RI of the typhoon. The CBs during pre-RI and RI are examined from dynamic and thermodynamic viewpoints. The combination of lower-level convergent inflow and upper-level divergent outflow pushes a relay-race-like transmission of convective activity, favorable for the development of deep convection. A double warm-core structure is induced by the centripetal outflow sinking and warming associated with CBs, which directly accelerates RI by a sudden decrease in hydrostatic pressure. By utilizing the convection activity degree(CAD) index derived from the local total energy anomaly, a correlation formula between CBs and CAD is deduced.Furthermore, an intense CAD(ICAD) signal threshold(with a value equal to 100) to predict CBs is obtained. It is verified that this ICAD threshold is effective for estimating the occurrence of a CB episode and predicting RI of a typhoon. Therefore,this threshold may be a valuable tool for identifying CB episodes and forecasting rapidly intensified typhoons. 展开更多
关键词 CONVECTIVE bursts RAPID INTENSIFICATION TYPHOON simulation
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Gamma-Ray Bursts: Afterglows and Central Engines 被引量:8
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作者 K.S.Cheng T.Lu 《Chinese Journal of Astronomy and Astrophysics》 CSCD 北大核心 2001年第1期1-20,共20页
Gamma-ray bursts (GRBs) are the most intense transient gamma-ray events in the sky; this, together with the strong evidence (the isotropic and inhomogeneous distribution of GRBs detected by BASTE) that they are locat... Gamma-ray bursts (GRBs) are the most intense transient gamma-ray events in the sky; this, together with the strong evidence (the isotropic and inhomogeneous distribution of GRBs detected by BASTE) that they are located at cosmological distances, makes them the most energetic events ever known. For example, the observed radiation energies of some GRBs are equivalent to the total convertion into radiation of the mass energy of more than one solar mass. This is thousand times stronger than the energy of a supernova explosion. Some unconventional energy mechanism and extremely high conversion efficiency for these mysterious events are required. The discovery of host galaxies and association with supernovae at cosmological distances by the recently launched satellite of BeppoSAX and ground based radio and optical telescopes in GRB afterglow provides further support to the cosmological origin of GRBs and put strong constraints on their central engine. It is the aim of this article to review the possible central engines, energy mechanisms, dynamical and spectral evolution of GRBs, especially focusing on the afterglows in multi-wavebands. 展开更多
关键词 gamma-rays: bursts - shock waves - ISM: jets and outflows- radiation mechanisms: non-thermal
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Extending the correlation of L_R-L_X to gamma-ray bursts 被引量:1
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作者 Jing L Jing-Wen Xing +3 位作者 Yuan-Chuan Zou Wei-Hua Lei Qing-Wen Wu Ding-Xiong Wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2015年第5期617-622,共6页
The well-known correlation between radio luminosity (LR) and X-ray luminosity (Lx), LR/LX 10^-5, holds for a variety of objects, such as active galactic nuclei, Galactic black holes, solar flares and cool stars.... The well-known correlation between radio luminosity (LR) and X-ray luminosity (Lx), LR/LX 10^-5, holds for a variety of objects, such as active galactic nuclei, Galactic black holes, solar flares and cool stars. Here we extend the relation to gamma-ray bursts (GRBs) and find that the GRBs also obey a similar LR - LX relation, with a slightly different slope of LR ∝ LX^1.1. This relation implies that the explosions that occur on different scales may have a common underlying origin. 展开更多
关键词 gamma-ray bursts general -- quasars general -- stars black holes
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Constraints on generalized Chaplygin gas model including gamma-ray bursts 被引量:1
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作者 Fa-Yin Wang Zi-Gao Dai Shi Qi 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2009年第5期547-557,共11页
Generalized Chaplygin gas (whose equation of state is PGCG = -A/ρGCG^α) was proposed as a candidate for unification of dark energy and dark matter. We investigate constraints on this model with the latest observed... Generalized Chaplygin gas (whose equation of state is PGCG = -A/ρGCG^α) was proposed as a candidate for unification of dark energy and dark matter. We investigate constraints on this model with the latest observed data. We test the model with type-Ia supernovae (SNe Ia), cosmic microwave background (CMB) anisotropy, X-ray gas mass fractions in clusters, and gamma-ray bursts (GRBs). We calibrate the GRB luminosity relations without assuming any cosmological models using SNe Ia. We show that GRBs can extend the Hubble diagram to higher redshifts (z 〉 6). The GRB Hubble diagram is well behaved and delineates the shape of the Hubble diagram well. We measure As≡A/ρGCG,0^α+1 =0.68-0.08^+0.04(where PGCG,0 is the energy density today) and α=-0.22 -0.13^+0.15 at the 1σ confidence level using all the datasets. Our results rule out the standard Chaplygin gas model (α = 1) at the 3σ confidence level. The ACDM is allowed at the 2σ confidence level. We find that acceleration could have started at a redshift of z - 0.70. The concordance of the generalized Chaplygin gas model with the age estimate of an old high redshift quasar is found. In addition, we show that GRBs can break the degeneracy between the generalized Chaplygin gas model and the XCDM model. 展开更多
关键词 gamma-rays bursts -- cosmology theory
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The Early X-ray Afterglows of Optically Bright and Dark Gamma-Ray Bursts 被引量:2
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作者 Yi-Qing Lin 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2006年第5期555-560,共6页
A systematic study on the early X-ray afterglows of both optically bright and dark gamma-ray bursts (B-GRBs and D-GRBs) observed by Swift is presented. Our sample includes 25 GRBs of which 13 are B-GRBs and 12 are D... A systematic study on the early X-ray afterglows of both optically bright and dark gamma-ray bursts (B-GRBs and D-GRBs) observed by Swift is presented. Our sample includes 25 GRBs of which 13 are B-GRBs and 12 are D-GRBs. Our results show that the distributions of the X-ray afterglow fluxes (Fx), the gamma-ray fluxes (Sγ), and the ratio (Rγ,x) are similar for the two kinds of GRBs, that any observed differences should be simply statistical fluctuation. These results indicate that the progenitors of the two kinds of GRBs are of the same population with comparable total energies of explosion. The suppression of optical emission in the D-GRBs should result from circumburst but not from their central engine. 展开更多
关键词 gamma rays bursts
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Verification of Short-Term Predictions of Solar Soft X-ray Bursts for the Maximum Phase (2000-2001) of Solar Cycle 23 被引量:3
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作者 Cui-Lian Zhu and Jia-Long WangNational Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 《Chinese Journal of Astronomy and Astrophysics》 CSCD 北大核心 2003年第6期563-568,共6页
We present a verification of the short-term predictions of solar X-ray bursts for the maximum phase (2000–2001) of Solar Cycle 23, issued by two prediction centers. The results are that the rate of correct prediction... We present a verification of the short-term predictions of solar X-ray bursts for the maximum phase (2000–2001) of Solar Cycle 23, issued by two prediction centers. The results are that the rate of correct predictions is about equal for RWC-China and WWA; the rate of too high predictions is greater for RWC-China than for WWA, while the rate of too low predictions is smaller for RWC-China than for WWA. 展开更多
关键词 sun: X-ray bursts sun: short-term prediction
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A quark nova in the wake of a core-collapse supernova:a unifying model for long duration gamma-ray bursts and fast radio bursts 被引量:1
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作者 Rachid Ouyed Denis Leahy Nico Koning 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2020年第2期119-186,共68页
By appealing to a quark nova(QN;the explosive transition of a neutron star to a quark star) in the wake of a core-collapse supernova(CCSN) explosion of a massive star,we develop a unified model for long duration gamma... By appealing to a quark nova(QN;the explosive transition of a neutron star to a quark star) in the wake of a core-collapse supernova(CCSN) explosion of a massive star,we develop a unified model for long duration gamma-ray bursts(LGRBs) and fast radio bursts(FRBs).The time delay(years to decades)between the SN and the QN,and the fragmented nature(i.e.,millions of chunks) of the relativistic QN ejecta are key to yielding a robust LGRB engine.In our model,an LGRB light curve exhibits the interaction of the fragmented QN ejecta with turbulent(i.e.,filamentary and magnetically saturated) SN ejecta which is shaped by its interaction with an underlying pulsar wind nebula(PWN).The afterglow is due to the interaction of the QN chunks,exiting the SN ejecta,with the surrounding medium.Our model can fit BAT/XRT prompt and afterglow light curves simultaneously with their spectra,thus yielding the observed properties of LGRBs(e.g.,the Band function and the X-ray flares).We find that the peak luminositypeak photon energy relationship(i.e.,the Yonetoku law),and the isotropic energy-peak photon energy relationship(i.e.,the Amati law) are not fundamental but phenomenological.FRB-like emission in our model results from coherent synchrotron emission(CSE) when the QN chunks interact with non-turbulent weakly magnetized PWN-SN ejecta,where conditions are prone to the Weibel instability.Magnetic field amplification induced by the Weibel instability in the shocked chunk frame sets the bunching length for electrons and pairs to radiate coherently.The resulting emission frequency,luminosity and duration in our model are consistent with FRB data.We find a natural unification of high-energy burst phenomena from FRBs(i.e.,those connected to CCSNe) to LGRBs including X-ray flashes(XRFs) and X-ray rich GRBs(XRR-GRBs) as well as superluminous SNe(SLSNe).We find a possible connection between ultra-high energy cosmic rays and FRBs and propose that a QN following a binary neutron star merger can yield a short duration GRB(SGRB) with fits to BAT/XRT light curves. 展开更多
关键词 stars:neutron stars:quark pulsars:general supernovae:general gamma-ray burst:general fast radio burst:general
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Redshift Independence of the Amati and Yonetoku Relations for Gamma-Ray Bursts 被引量:2
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作者 Walid J. Azzam Mohamed J. Alothman 《International Journal of Astronomy and Astrophysics》 2013年第4期372-375,共4页
The Amati and Yonetoku relations are two of the main energy and luminosity correlations that currently exist for gamma-ray bursts (GRBs). The Amati relation is a correlation between the intrinsic peak energy, Epeak, i... The Amati and Yonetoku relations are two of the main energy and luminosity correlations that currently exist for gamma-ray bursts (GRBs). The Amati relation is a correlation between the intrinsic peak energy, Epeak, in the vFv spectrum of a burst and its equivalent isotropic energy, Eiso. The Yonetoku relation is a correlation between Epeak and the isotropic peak luminosity, Liso. In this paper, we use a recent data sample of 65 GRBs to investigate whether these two relations evolve with redshift, z. The z-correction and the?k-correction are both taken into account. Our method consists of binning the data in redshift, z, then applying (for each bin) a fit of the form:?log(Eiso) = A + Blog(Epeak/Epeak>) for the Amati relation, and of the form:?log(Liso) = A + Blog(Epeak/Epeak>) for the Yonetoku relation, where Epeak> is the mean value of the peak energy for the entire sample. The objective is to see whether the two fitting parameters, A and B, evolve systematically with z. Good least-squares fits were obtained with reasonable values for the linear regression coefficient, r. Our results indicate that the normalization, A, and the slope, B, do not evolve with redshift, and hence the Amati and Yonetoku relations seem to be redshift independent. 展开更多
关键词 GAMMA-RAY bursts Energy Correlations LUMINOSITY Indicators REDSHIFT Evolution
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Study on fault induced rock bursts 被引量:17
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作者 LI Zhi-hua DOU Lin-ming +2 位作者 LU Cai-ping MU Zong-long CAO An-ye 《Journal of China University of Mining and Technology》 EI 2008年第3期321-326,共6页
In order to study the rules of rock bursts caused by faults by means of mechanical analysis of a roof rock-mass balanced structure and numerical simulation about fault slip destabilization, the effect of coal mining o... In order to study the rules of rock bursts caused by faults by means of mechanical analysis of a roof rock-mass balanced structure and numerical simulation about fault slip destabilization, the effect of coal mining operation on fault plane stresses and slip displacement were studied. The results indicate that the slip displacement sharply increases due to the decrease of normal stress and the increase of shear stress at the fault plane when the working face advances from the footwall to the fault itself, which may induce a fault rock burst. However, this slip displacement will be very small due to the increase of normal stress and the decrease of shear stress when the working face advances from the hanging wall to the fault itself, which results in a very small risk of a fault rock burst. 展开更多
关键词 FAULT slip destabilization rock burst numerical simulation normal stress shear stress
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