Fast radio bursts(FRBs)are extragalactic radio transients with millisecond duration and brightness temperature.An FRB-associated X-ray burst(XRB)was recently found to arise from the Galactic magnetar SGR J1935+2154.Fo...Fast radio bursts(FRBs)are extragalactic radio transients with millisecond duration and brightness temperature.An FRB-associated X-ray burst(XRB)was recently found to arise from the Galactic magnetar SGR J1935+2154.Following the model of Dai,in which an FRB may originate from a magnetar encountering an asteroid,we focus on explaining the spectrum of the XRB associated with FRB 200428 from SGR J1935+2154.Collisions between asteroidal fragments and the magnetar surface produce a fireball,which further expands relativistically.Due to the velocity difference among some shells in the fireball,internal shocks would form far away from the magnetar,and further emit X-ray emission.We propose that the FRB-associated XRB can be produced by synchrotron emission from the internal shocks,and then constrain the physical parameters by the observed XRB spectrum.展开更多
Gamma-ray bursts(GRBs)exhibit powerful radiation and relativistic jets similar to blazars.However,the central engine of GRBs remains unknown.In this paper,we use the fundamental plane to analyze a sample of GRBs with ...Gamma-ray bursts(GRBs)exhibit powerful radiation and relativistic jets similar to blazars.However,the central engine of GRBs remains unknown.In this paper,we use the fundamental plane to analyze a sample of GRBs with measured mass.We extend,over~12 orders of magnitude,the correlation analysis and fundamental plane with a sample of X-ray binaries,active galactic nuclei(AGNs)including blazars,and brightest cluster galaxies.The fundamental plane of our de-beamed sample,with a measured mass(logL_(R)=(0.60±0.03)logL_(X)+(0.78±0.02)logM+7.23±0.95),closely aligns with the findings of previous work on AGNs.This finding suggests that GRBs adhere to the fundamental plane of AGNs and supports the theory proposed in previous work that the central engine of GRBs may be black holes.This observation provides a plausible explanation for the striking similarities between GRBs and AGNs.展开更多
It is conjectured that coherent re-emission of cyclotron resonance absorption could result in pulsar giant pulses.This conjecture seems reasonable as it can naturally explain the distribution of pulsars with giant pul...It is conjectured that coherent re-emission of cyclotron resonance absorption could result in pulsar giant pulses.This conjecture seems reasonable as it can naturally explain the distribution of pulsars with giant pulses on the P-P diagram.展开更多
基金supported by the National Key Research and Development Program of China(Grant Nos.2017YFA0402600,2018YFA0404204)the National SKA Program of China(Grant No.2020SKA0120300)+9 种基金the National Natural Science Foundation of China(NSFC,Grant Nos.11833003,U2038105)supported by the National Natural Science Foundation of China(NSFC,Grant No.12003028)support from the National Natural Science Foundation of China(NSFC,Grant No.U1838113)the National Natural Science Foundation of China(NSFC,Grant Nos.11833003 and U2038105)the Program for Innovative Talents,Entrepreneur in JiangsuYunnan University(Grant No.C176220100087)support by Fundamental Research Funds for the Central Universities(14380046)the National Key Research and Development Programs of China(2018YFA0404204)the science research grants from the China Manned Space Project with NO.CMS-CSST-2021-B11the Program for Innovative Talents,Entrepreneur in Jiangsu。
文摘Fast radio bursts(FRBs)are extragalactic radio transients with millisecond duration and brightness temperature.An FRB-associated X-ray burst(XRB)was recently found to arise from the Galactic magnetar SGR J1935+2154.Following the model of Dai,in which an FRB may originate from a magnetar encountering an asteroid,we focus on explaining the spectrum of the XRB associated with FRB 200428 from SGR J1935+2154.Collisions between asteroidal fragments and the magnetar surface produce a fireball,which further expands relativistically.Due to the velocity difference among some shells in the fireball,internal shocks would form far away from the magnetar,and further emit X-ray emission.We propose that the FRB-associated XRB can be produced by synchrotron emission from the internal shocks,and then constrain the physical parameters by the observed XRB spectrum.
基金partially supported by the Natural Science Foundation of Yunnan Province(grant No.202101AU070006)the Young and Middle-Aged Academic and Technical Reserve Talents of Yunnan Province(202205AC160087)。
文摘Gamma-ray bursts(GRBs)exhibit powerful radiation and relativistic jets similar to blazars.However,the central engine of GRBs remains unknown.In this paper,we use the fundamental plane to analyze a sample of GRBs with measured mass.We extend,over~12 orders of magnitude,the correlation analysis and fundamental plane with a sample of X-ray binaries,active galactic nuclei(AGNs)including blazars,and brightest cluster galaxies.The fundamental plane of our de-beamed sample,with a measured mass(logL_(R)=(0.60±0.03)logL_(X)+(0.78±0.02)logM+7.23±0.95),closely aligns with the findings of previous work on AGNs.This finding suggests that GRBs adhere to the fundamental plane of AGNs and supports the theory proposed in previous work that the central engine of GRBs may be black holes.This observation provides a plausible explanation for the striking similarities between GRBs and AGNs.
基金supported by the National Key R&D Program of China(Grant No.2018YFA0404703)the National Natural Science Foundation of China(Grant Nos.11673002,12003047 and U1531243)the Open Project Program of the Key Laboratory of FAST,NAOC,Chinese Academy of Sciences。
文摘It is conjectured that coherent re-emission of cyclotron resonance absorption could result in pulsar giant pulses.This conjecture seems reasonable as it can naturally explain the distribution of pulsars with giant pulses on the P-P diagram.
