Opioids,such as morphine,are the most potent drugs used to treat pain.Long-term use results in high tolerance to morphine.High mobility group box-1(HMGB1) has been shown to participate in neuropathic or inflammatory p...Opioids,such as morphine,are the most potent drugs used to treat pain.Long-term use results in high tolerance to morphine.High mobility group box-1(HMGB1) has been shown to participate in neuropathic or inflammatory pain,but its role in morphine tolerance is unclear.In this study,we established rat and mouse models of morphine tolerance by intrathecal injection of morphine for 7 consecutive days.We found that morphine induced rat spinal cord neurons to release a large amount of HMGB1.HMGB1 regulated nuclear factor κB p65 phosphorylation and interleukin-1β production by increasing Toll-like receptor 4receptor expression in microglia,thereby inducing morphine tolerance.Glycyrrhizin,an HMGB1 inhibito r,markedly attenuated chronic morphine tole rance in the mouse model.Finally,compound C(adenosine 5’-monophosphate-activated protein kinase inhibitor) and zinc protoporphyrin(heme oxygenase-1 inhibitor)alleviated the morphine-induced release of HMGB1 and reduced nuclear factor κB p65 phosphorylation and interleukin-1β production in a mouse model of morphine tolerance and an SH-SY5Y cell model of morphine tole rance,and alleviated morphine tolerance in the mouse model.These findings suggest that morphine induces HMGB1 release via the adenosine 5’-monophosphate-activated protein kinase/heme oxygenase-1 signaling pathway,and that inhibiting this signaling pathway can effectively reduce morphine tole rance.展开更多
Fast radio bursts(FRBs) are highly dispersed millisecond-duration radio bursts,[1,2]of which the physical origin is still not fully understood. FRB 20201124A is one of the most actively repeating FRBs. In this paper, ...Fast radio bursts(FRBs) are highly dispersed millisecond-duration radio bursts,[1,2]of which the physical origin is still not fully understood. FRB 20201124A is one of the most actively repeating FRBs. In this paper, we present the collection of 1863 burst dynamic spectra of FRB 20201124A measured with the Five-hundred-meter Aperture Spherical radio Telescope(FAST). The current collection, taken from the observation during the FRB active phase from April to June 2021, is the largest burst sample detected for any FRB so far. The standard PSRFITs format is adopted, including dynamic spectra of the burst, and the time information of the dynamic spectra, in addition, mask files help readers to identify the pulse positions are also provided. The dataset is available in Science Data Bank, with the link https://www.doi.org/10.57760/sciencedb.j00113.00076.展开更多
A conservative constraint on the rest mass of the photon can be estimated under the assumption that the frequency dependence of dispersion from astronomical sources is mainly contributed by the nonzero photon mass eff...A conservative constraint on the rest mass of the photon can be estimated under the assumption that the frequency dependence of dispersion from astronomical sources is mainly contributed by the nonzero photon mass effect. Photon mass limits have been set earlier through the optical emissions of the Crab Nebula pulsar, but we demonstrate that these limits can be significantly improved with the dispersion measure(DM) measurements of radio pulsars in the Large and Small Magellanic Clouds.The combination of DM measurements of pulsars and distances of the Magellanic Clouds provides a strict upper limit on the photon mass as low as m_γ≤ 2.0 × 10^(-45) g, which is at least four orders of magnitude smaller than the constraint from the Crab Nebula pulsar. Although our limit is not as tight as the current best result(~ 10^(-47)g) from a fast radio burst(FRB 150418) at a cosmological distance,the cosmological origin of FRB 150418 remains under debate; and our limit can reach the same high precision of FRB 150418 when it has an extragalactic origin(~ 10^(-45)g).展开更多
In the fireball model, it is more physically realistic that gamma-rayburst (GRB) ejecta have a range of bulk Lorentz factors (assuming M ∝Γ-s). The low Lorentz factor part of the ejecta will catch up with the high L...In the fireball model, it is more physically realistic that gamma-rayburst (GRB) ejecta have a range of bulk Lorentz factors (assuming M ∝Γ-s). The low Lorentz factor part of the ejecta will catch up with the high Lorentz factor part when the latter is decelerated by the surrounding medium to a comparable Lorentz factor. Such a process will develop a long-lasting weak reverse shock until the whole ejecta are shocked. Meanwhile, the forward shocked materials are gradually supplied with energy from the ejecta that are catching-up, and thus the temporal decay of the forward shock emission will be slower than that without an energy supply. However, the reverse shock may be strong. Here, we extend the standard reverse-forward shock model to the case of radially nonuniform ejecta. We show that this process can be classified into two cases: the thick shell case and the thin shell case. In the thin shell case, the reverse shock is weak and the temporal scaling law of the afterglow is the same as that in Sari & Me′sza′ros (2000). However, in the thick shell case, the reverse shock is strong and thus its emission dominates the afterglow in the high energy band. Our results also show slower decaying behavior of the afterglow due to the energy supply by low Lorentz factor materials, which may help the understanding of the plateau observed in the early optical and X-ray afterglows.展开更多
Swift GRB 100418A is a long burst at z = 0.624 without detection of any associated supernova (SN). Its light curves in both the prompt and afterglow phases are similar to GRB 060614, a nearby long GRB without an assoc...Swift GRB 100418A is a long burst at z = 0.624 without detection of any associated supernova (SN). Its light curves in both the prompt and afterglow phases are similar to GRB 060614, a nearby long GRB without an associated SN. We analyze the observational data of this event and discuss the possible origins of its multiwavelength emission. We show that its joint light curve at 1 keV derived from Swift BAT and XRT observations is composed of two distinguished components. The first component, whose spectrum is extremely soft (Γ = 4.32), ends with a steep decay segment, indicating the internal origin of this component. The second component is a slowly-rising, broad bump which peaks at ～ 10 5 s post the BAT trigger. Assuming that the late bump is due to onset of the afterglow, we derive the initial Lorentz factor (Γ 0 ) of the GRB fireball and find that it significantly deviates from the relation between the Γ 0 and isotropic gamma-ray energy derived from typical GRBs. We also check whether it follows the same anti-correlation between X-ray luminosity and the break time observed in the shallow decay phase of many typical GRBs, which is usually regarded as a signal of late energy injection from the GRB central engine. However, we find that it does not obey this correlation. We propose that the late bump could be contributed by a two-component jet. We fit the second component with an off-axis jet model for a constant medium density and find the late bump can be represented by the model. The derived jet half-opening angle is 0.30 rad and the viewing angle is 0.315 rad. The medium density is 0.05 cm 3 , possibly suggesting that it may be from a merger of compact stars. The similarity between GRBs 060614 and 100418A may indicate that the two GRBs are from the same population and the late bump observed in the two GRBs may be a signal of a two-component jet powered by the GRB central engine.展开更多
Synchrotron emission polarization is very sensitive to the magnetic field configuration.Recently,polarization of synchrotron emission with a mixed(SM)magnetic field in the gamma-ray burst(GRB)afterglow phase has been ...Synchrotron emission polarization is very sensitive to the magnetic field configuration.Recently,polarization of synchrotron emission with a mixed(SM)magnetic field in the gamma-ray burst(GRB)afterglow phase has been developed.Here,we apply these SM models to the GRB prompt phase and compare their polarization properties with that of synchrotron emission in purely ordered(SO)magnetic field.We find that the polarization properties in an SM model are very similar to these in a corresponding SO model(e.g.,synchrotron emission in a mixed magnetic field with an aligned ordered part(SMA)and synchrotron emission with a purely ordered aligned magnetic field(SOA)),only with a lower polarization degree(PD).We also discuss the statistical properties of the models.We find PDs of the simulated bursts are concentrated around 25%for both SOA and synchrotron emission in a purely ordered toroidal magnetic field(SOT),while they can range from 0%to 25%for SMA and synchrotron emission in a mixed magnetic field with a toroidal ordered part(SMT),depending onξ_B value,i.e.,the ratio of magnetic reduction of the ordered magnetic field over that of random magnetic field.From statistics,if PDs of majority GRBs are non-zero,then it favors SO and SM models.Further,if there are some bright GRBs with prominently lower PDs than that of the majority GRBs,it favors SOT(SMT)models;if all the bright GRBs have comparable PDs with the majority ones,it favors SOA(SMA)models.Finally,we apply our results to POLAR’s data and find that~10%time-integrated PDs of the observed bursts favor SMA and SMT models,and theξ_B parameter of these bursts is constrained to be around 1.135.展开更多
Explosive astrophysical transients at cosmological distances can be used to place precision tests of the basic assumptions of relativity theory,such as Lorentz invariance,the photon zero-mass hypothesis,and the weak e...Explosive astrophysical transients at cosmological distances can be used to place precision tests of the basic assumptions of relativity theory,such as Lorentz invariance,the photon zero-mass hypothesis,and the weak equivalence principle(WEP).Signatures of Lorentz invariance violations(LIV)include vacuum dispersion and vacuum birefringence.Sensitive searches for LIV using astrophysical sources such as gamma-ray bursts,active galactic nuclei,and pulsars are discussed.The most direct consequence of a nonzero photon rest mass is a frequency dependence in the velocity of light propagating in vacuum.A detailed representation of how to obtain a combined severe limit on the photon mass using fast radio bursts at different redshifts through the dispersion method is presented.The accuracy of the WEP has been well tested based on the Shapiro time delay of astrophysical messengers traveling through a gravitational field.Some caveats of Shapiro delay tests are discussed.In this article,we review and update the status of astrophysical tests of fundamental physics.展开更多
The variability in multi-pulse gamma-ray bursts(GRBs)may help to reveal the mechanism of underlying processes from the central engine.To investigate whether the self-organized criticality(SOC)phenomena exist in the pr...The variability in multi-pulse gamma-ray bursts(GRBs)may help to reveal the mechanism of underlying processes from the central engine.To investigate whether the self-organized criticality(SOC)phenomena exist in the prompt phase of GRBs,we statistically study the proper ties of GRBs with more than 3 pulses in each burst by fitting the distributions of several observed physical variables with a Markov Chain Monte Carlo approach,including the isotropic energy E_(iso),the duration time T,and the peak count rate P of each pulse.Our sample consists of 454 pulses in 93 GRBs observed by the CGRO/BATSE satellite.The best-fitting values and uncertainties for these power-law indices of the differential frequency distributions are:α_(E)^(d)=1.54±0.09,α_(T)^(d)=1.82_(-0.15)^(+0.14)andα_(P)^(d)=2.09_(-0.19)^(0.18),while the power-law indices in the cumulative frequency distributions are:α_(E)^(c)=1.44_(-0.10)^(+0.08),α_(T)^(c)=1.75_(-0.13)^(0.11)andα_(P)^(c)=1.99_(-0.19)^(+0.16).We find that these distributions are roughly consistent with the physical framework of a Fractal-Diffusive,Self^Organized Criticality(FD-SOC)system with the spatial dimension S=3 and the classical diffusionβ=1.Our results support that the jet responsible for the GRBs should be magnetically dominated and magnetic instabilities(e.g.,kink model,or tearing-model instability)lead the GRB emission region into the SOC state.展开更多
There are some similarities between bursts of repeating fast radio bursts(FRBs)and giant pulses(GPs)of pulsars.To explore possible relations between them,we study the cumulative energy distributions of these two pheno...There are some similarities between bursts of repeating fast radio bursts(FRBs)and giant pulses(GPs)of pulsars.To explore possible relations between them,we study the cumulative energy distributions of these two phenomena using the observations of repeating FRB 121102 and the GPs of Crab pulsar.We find that the power-law slope of GPs(with fuence≥130 Jy.ms)is 2.85±0.10.The energy distribution of FRB 121102 can be well fitted by a smooth broken power-law function.For the bursts of FRB 121102 above the break energy(1.22×10^(37)erg),the best-ftting slope is 2.90^(+0.55)_(-0344),similar to the index of GPs at the same observing frequency(~1.4 GHz).We further discuss the physical origin of the repeating FRB 121102 in the framework of the super GPs model.And we find that the super GPs model involving a millisecond pulsar is workable and favored for explaining FRB 121102 despite that the magnetar burst model is more popular.展开更多
基金supported by the National Natural Science Foundation of ChinaNos.81971047 (to WTL) and 82073910 (to XFW)+2 种基金the Natural Science Foundation of Jiangsu Province,No.BK20191253 (to XFW)Key R&D Program (Social Development) Project of Jiangsu Province,No.BE2019 732 (to WTL)Jiangsu Province Hospital (the First Affiliated Hospital of Nanjing Medical University) Clinical Capacity Enhancement Project,No.JSPH-511B2018-8 (to YBP)。
文摘Opioids,such as morphine,are the most potent drugs used to treat pain.Long-term use results in high tolerance to morphine.High mobility group box-1(HMGB1) has been shown to participate in neuropathic or inflammatory pain,but its role in morphine tolerance is unclear.In this study,we established rat and mouse models of morphine tolerance by intrathecal injection of morphine for 7 consecutive days.We found that morphine induced rat spinal cord neurons to release a large amount of HMGB1.HMGB1 regulated nuclear factor κB p65 phosphorylation and interleukin-1β production by increasing Toll-like receptor 4receptor expression in microglia,thereby inducing morphine tolerance.Glycyrrhizin,an HMGB1 inhibito r,markedly attenuated chronic morphine tole rance in the mouse model.Finally,compound C(adenosine 5’-monophosphate-activated protein kinase inhibitor) and zinc protoporphyrin(heme oxygenase-1 inhibitor)alleviated the morphine-induced release of HMGB1 and reduced nuclear factor κB p65 phosphorylation and interleukin-1β production in a mouse model of morphine tolerance and an SH-SY5Y cell model of morphine tole rance,and alleviated morphine tolerance in the mouse model.These findings suggest that morphine induces HMGB1 release via the adenosine 5’-monophosphate-activated protein kinase/heme oxygenase-1 signaling pathway,and that inhibiting this signaling pathway can effectively reduce morphine tole rance.
基金supported by the National SKA Program of China (Grant Nos. 2020SKA0120100 and 2020SKA0120200)the National Natural Science Foundation of China (Grant Nos. 12041304, 11873067, 11988101, 12041303, 11725313, 11725314, 11833003, 12003028, 12041306, 12103089, U2031209, U2038105, and U1831207)+8 种基金the National Key Research and Development Program of China (Grant Nos. 2019YFA0405100, 2017YFA0402602, 2018YFA0404204, and 2016YFA0400801)Key Research Program of the Chinese Academy of Sciences (Grant No. QYZDJ-SSW-SLH021)Natural Science Foundation of Jiangsu Province (Grant No. BK20211000)Cultivation Project for FAST Scientific Payoff and Research Achievement of CAMS-CAS, the Strategic Priority Research Program on Space Science, the Western Light Youth Project of Chinese Academy of Sciences (Grant Nos. XDA15360000, XDA15052700, and XDB23040400)funding from the MaxPlanck Partner Group, the science research grants from the China Manned Space Project (Grant Nos. CMS-CSST2021-B11 and CMS-CSST-2021-A11)PKU development (Grant No. 7101502590)support from the XPLORER PRIZEsupported by Fundamental Research Funds for the Central Universities (Grant No. 14380046)the Program for Innovative Talents, Entrepreneur in Jiangsu。
文摘Fast radio bursts(FRBs) are highly dispersed millisecond-duration radio bursts,[1,2]of which the physical origin is still not fully understood. FRB 20201124A is one of the most actively repeating FRBs. In this paper, we present the collection of 1863 burst dynamic spectra of FRB 20201124A measured with the Five-hundred-meter Aperture Spherical radio Telescope(FAST). The current collection, taken from the observation during the FRB active phase from April to June 2021, is the largest burst sample detected for any FRB so far. The standard PSRFITs format is adopted, including dynamic spectra of the burst, and the time information of the dynamic spectra, in addition, mask files help readers to identify the pulse positions are also provided. The dataset is available in Science Data Bank, with the link https://www.doi.org/10.57760/sciencedb.j00113.00076.
基金partially supported by the National Basic Research Program of China(973 Program,Grant Nos.2014CB845800 and 2013CB834900)the National Natural Science Foundation of China(Grant Nos.11322328,11433009,11673068 and 11603076)+4 种基金the Youth Innovation Promotion Association(2011231)the Key Research Program of Frontier Sciences(QYZDBSSW-SYS005)the Strategic Priority Research Program“The Emergence of Cosmological Structures”(Grant No.XDB09000000)of the Chinese Academy of Sciencesthe Natural Science Foundation of Jiangsu Province(Grant No.BK20161096)the Guangxi Key Laboratory for Relativistic Astrophysics
文摘A conservative constraint on the rest mass of the photon can be estimated under the assumption that the frequency dependence of dispersion from astronomical sources is mainly contributed by the nonzero photon mass effect. Photon mass limits have been set earlier through the optical emissions of the Crab Nebula pulsar, but we demonstrate that these limits can be significantly improved with the dispersion measure(DM) measurements of radio pulsars in the Large and Small Magellanic Clouds.The combination of DM measurements of pulsars and distances of the Magellanic Clouds provides a strict upper limit on the photon mass as low as m_γ≤ 2.0 × 10^(-45) g, which is at least four orders of magnitude smaller than the constraint from the Crab Nebula pulsar. Although our limit is not as tight as the current best result(~ 10^(-47)g) from a fast radio burst(FRB 150418) at a cosmological distance,the cosmological origin of FRB 150418 remains under debate; and our limit can reach the same high precision of FRB 150418 when it has an extragalactic origin(~ 10^(-45)g).
基金supported by the National Natural Science Foundation of China(grant Nos. 10473023, 10503012, 10621303, 10633040 and 10703002)the National Basic Research Program of China (973 Program 2009CB824800)XFW also thanks the support of the NSF AST0307376, NASA NNX07AJ62G, NNX08AL40G, the China Postdoctoral Science Foundation, and the Postdoctoral Research Award of Jiangsu Province
文摘In the fireball model, it is more physically realistic that gamma-rayburst (GRB) ejecta have a range of bulk Lorentz factors (assuming M ∝Γ-s). The low Lorentz factor part of the ejecta will catch up with the high Lorentz factor part when the latter is decelerated by the surrounding medium to a comparable Lorentz factor. Such a process will develop a long-lasting weak reverse shock until the whole ejecta are shocked. Meanwhile, the forward shocked materials are gradually supplied with energy from the ejecta that are catching-up, and thus the temporal decay of the forward shock emission will be slower than that without an energy supply. However, the reverse shock may be strong. Here, we extend the standard reverse-forward shock model to the case of radially nonuniform ejecta. We show that this process can be classified into two cases: the thick shell case and the thin shell case. In the thin shell case, the reverse shock is weak and the temporal scaling law of the afterglow is the same as that in Sari & Me′sza′ros (2000). However, in the thick shell case, the reverse shock is strong and thus its emission dominates the afterglow in the high energy band. Our results also show slower decaying behavior of the afterglow due to the energy supply by low Lorentz factor materials, which may help the understanding of the plateau observed in the early optical and X-ray afterglows.
基金supported by the National Natural Science Foundation of China (Grants Nos.11025313, 10873002 and 11078008)National Basic Research Program of China (973 Program, Grant No.2009CB824800)+2 种基金Chinese Academy of Sciences (Grant KJCXZ-YW-T19)Guangxi SHI-BAI-QIAN project (Grant No.2007201)Guangxi Science Foundation (2010GXNSFC013011, 2011-135)
文摘Swift GRB 100418A is a long burst at z = 0.624 without detection of any associated supernova (SN). Its light curves in both the prompt and afterglow phases are similar to GRB 060614, a nearby long GRB without an associated SN. We analyze the observational data of this event and discuss the possible origins of its multiwavelength emission. We show that its joint light curve at 1 keV derived from Swift BAT and XRT observations is composed of two distinguished components. The first component, whose spectrum is extremely soft (Γ = 4.32), ends with a steep decay segment, indicating the internal origin of this component. The second component is a slowly-rising, broad bump which peaks at ～ 10 5 s post the BAT trigger. Assuming that the late bump is due to onset of the afterglow, we derive the initial Lorentz factor (Γ 0 ) of the GRB fireball and find that it significantly deviates from the relation between the Γ 0 and isotropic gamma-ray energy derived from typical GRBs. We also check whether it follows the same anti-correlation between X-ray luminosity and the break time observed in the shallow decay phase of many typical GRBs, which is usually regarded as a signal of late energy injection from the GRB central engine. However, we find that it does not obey this correlation. We propose that the late bump could be contributed by a two-component jet. We fit the second component with an off-axis jet model for a constant medium density and find the late bump can be represented by the model. The derived jet half-opening angle is 0.30 rad and the viewing angle is 0.315 rad. The medium density is 0.05 cm 3 , possibly suggesting that it may be from a merger of compact stars. The similarity between GRBs 060614 and 100418A may indicate that the two GRBs are from the same population and the late bump observed in the two GRBs may be a signal of a two-component jet powered by the GRB central engine.
基金supported by the National Key Research and Development Program of China(Grant No.2017YFA0402600)the National Natural Science Foundation of China(NSFC)(Grant Nos.11573014,11673068,11725314,11833003 and 11903014)+6 种基金partially supported by the Key Research Program of Frontier Sciences(QYZDB-SSW-SYS005)the Strategic Priority Research Program“Multi-waveband gravitational wave Universe”(Grant No.XDB23040000)of the Chinese Academy of Sciencesthe“333 Project”of Jiangsu provincesupported by the Natural Science Foundation of Jiangsu Province(Grant No.BK 20171109)the Fundamental Research Funds for the Central Universitiesin part by NSFC(Grant No.11847310)the Seeds Funding of Jilin University。
文摘Synchrotron emission polarization is very sensitive to the magnetic field configuration.Recently,polarization of synchrotron emission with a mixed(SM)magnetic field in the gamma-ray burst(GRB)afterglow phase has been developed.Here,we apply these SM models to the GRB prompt phase and compare their polarization properties with that of synchrotron emission in purely ordered(SO)magnetic field.We find that the polarization properties in an SM model are very similar to these in a corresponding SO model(e.g.,synchrotron emission in a mixed magnetic field with an aligned ordered part(SMA)and synchrotron emission with a purely ordered aligned magnetic field(SOA)),only with a lower polarization degree(PD).We also discuss the statistical properties of the models.We find PDs of the simulated bursts are concentrated around 25%for both SOA and synchrotron emission in a purely ordered toroidal magnetic field(SOT),while they can range from 0%to 25%for SMA and synchrotron emission in a mixed magnetic field with a toroidal ordered part(SMT),depending onξ_B value,i.e.,the ratio of magnetic reduction of the ordered magnetic field over that of random magnetic field.From statistics,if PDs of majority GRBs are non-zero,then it favors SO and SM models.Further,if there are some bright GRBs with prominently lower PDs than that of the majority GRBs,it favors SOT(SMT)models;if all the bright GRBs have comparable PDs with the majority ones,it favors SOA(SMA)models.Finally,we apply our results to POLAR’s data and find that~10%time-integrated PDs of the observed bursts favor SMA and SMT models,and theξ_B parameter of these bursts is constrained to be around 1.135.
基金supported by the National Key Research and Development Program of China(2022YFA1603200,2022YFA1603201,and 2022SKA0130100)the Science Challenging Project(TZ2018005)+4 种基金the National Natural Science Foundation of China(12135001,11825502,11921006,11725314,12273113,11903019,11833003,and 12041306)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA25050900)the CAS Project for Young Scientists in Basic Research(YSBR-063)the Youth Innovation Promotion Association(2023331)support from the National Natural Science Funds for Distinguished Young Scholars(11825502)。
基金the National Natural Science Foundation of China(Grant Nos.11673068,11725314,U1831122,and 12041306)the Youth Innovation Promotion Association(2017366),the Key Research Program of Frontier Sciences(Grant Nos.QYZDB-SSW-SYS005 and ZDBS-LY-7014)the Strategic Priority Research Program“Multi-waveband gravitational wave universe”(Grant No.XDB23000000)of Chinese Academy of Sciences.
文摘Explosive astrophysical transients at cosmological distances can be used to place precision tests of the basic assumptions of relativity theory,such as Lorentz invariance,the photon zero-mass hypothesis,and the weak equivalence principle(WEP).Signatures of Lorentz invariance violations(LIV)include vacuum dispersion and vacuum birefringence.Sensitive searches for LIV using astrophysical sources such as gamma-ray bursts,active galactic nuclei,and pulsars are discussed.The most direct consequence of a nonzero photon rest mass is a frequency dependence in the velocity of light propagating in vacuum.A detailed representation of how to obtain a combined severe limit on the photon mass using fast radio bursts at different redshifts through the dispersion method is presented.The accuracy of the WEP has been well tested based on the Shapiro time delay of astrophysical messengers traveling through a gravitational field.Some caveats of Shapiro delay tests are discussed.In this article,we review and update the status of astrophysical tests of fundamental physics.
基金supported by the National Natural Science Foundation of China(Grant Nos.11673068,11725314,U1831122,11703064,11903019,U1938116)the Shanghai Sailing Program(No.17YF1422600)+2 种基金the Youth Innovation Promotion Association(2017366)the Key Research Program of Frontier Sciences(Grant Nos.QYZDB-SSW-SYS005,ZDBS-LY-7014)the Strategic Priority Research Program uMulti-waveband gravitational wave Universe”(Grant No.XDB23000000)of the Chinese Academy of Sciences.
文摘The variability in multi-pulse gamma-ray bursts(GRBs)may help to reveal the mechanism of underlying processes from the central engine.To investigate whether the self-organized criticality(SOC)phenomena exist in the prompt phase of GRBs,we statistically study the proper ties of GRBs with more than 3 pulses in each burst by fitting the distributions of several observed physical variables with a Markov Chain Monte Carlo approach,including the isotropic energy E_(iso),the duration time T,and the peak count rate P of each pulse.Our sample consists of 454 pulses in 93 GRBs observed by the CGRO/BATSE satellite.The best-fitting values and uncertainties for these power-law indices of the differential frequency distributions are:α_(E)^(d)=1.54±0.09,α_(T)^(d)=1.82_(-0.15)^(+0.14)andα_(P)^(d)=2.09_(-0.19)^(0.18),while the power-law indices in the cumulative frequency distributions are:α_(E)^(c)=1.44_(-0.10)^(+0.08),α_(T)^(c)=1.75_(-0.13)^(0.11)andα_(P)^(c)=1.99_(-0.19)^(+0.16).We find that these distributions are roughly consistent with the physical framework of a Fractal-Diffusive,Self^Organized Criticality(FD-SOC)system with the spatial dimension S=3 and the classical diffusionβ=1.Our results support that the jet responsible for the GRBs should be magnetically dominated and magnetic instabilities(e.g.,kink model,or tearing-model instability)lead the GRB emission region into the SOC state.
基金This work was partially supported by the National Natural Science Foundation of China(Grant Nos.11673068,11725314,U1831122,11903019,11533003,and 11703002)the Youth Innovation Promotion Association(2017366)+4 种基金the Key Research Program of Frontier Sciences(Grant Nos.QYZDB-SSW-SYS005 and ZDBS-LY-7014)the Strategic Priority Research Program"Multi-waveband gravita-tional wave universe"(Grant No.XDB23000000)the Chinese Academy of Sciences,the China Post-doctoral Science Foundation(Nos.2018M631242 and 2020M671876)the Fundamental Research Funds for the Central Universitiesthe National Postdoctoral Program for Innovative Talents(Grant No.BX20200164).
文摘There are some similarities between bursts of repeating fast radio bursts(FRBs)and giant pulses(GPs)of pulsars.To explore possible relations between them,we study the cumulative energy distributions of these two phenomena using the observations of repeating FRB 121102 and the GPs of Crab pulsar.We find that the power-law slope of GPs(with fuence≥130 Jy.ms)is 2.85±0.10.The energy distribution of FRB 121102 can be well fitted by a smooth broken power-law function.For the bursts of FRB 121102 above the break energy(1.22×10^(37)erg),the best-ftting slope is 2.90^(+0.55)_(-0344),similar to the index of GPs at the same observing frequency(~1.4 GHz).We further discuss the physical origin of the repeating FRB 121102 in the framework of the super GPs model.And we find that the super GPs model involving a millisecond pulsar is workable and favored for explaining FRB 121102 despite that the magnetar burst model is more popular.
