Rotating Radio Transients(RRATs)are a relatively new subclass of pulsars that emit detectable radio bursts sporadically.We analyzed 10 RRATs observed using the Parkes telescope,with eight of these observed via the ult...Rotating Radio Transients(RRATs)are a relatively new subclass of pulsars that emit detectable radio bursts sporadically.We analyzed 10 RRATs observed using the Parkes telescope,with eight of these observed via the ultra-wide-bandwidth low-frequency(UWL)receiver.We measured the burst rate and produced integrated profiles spanning multiple frequency bands for three RRATs.We also conducted a spectral analysis on both integrated pulses and individual pulses of three RRATs.All of their integrated pulses follow a simple power law,consistent with the known range of pulsar spectral indices.Their average spectral indices of single pulses are-0.9,-1.2,and-1.0 respectively,which are within the known range of pulsar spectral indices.Additionally,we find that the spreads of single-pulse spectral indices for these RRATs(ranging from-3.5 to+0.5)are narrower compared to what has been observed in other RRATs.Notably,the average spectral index and scatter of single pulses are both relatively small.For the remaining five RRATs observed at the UWL receiver,we also provide the upper limits on fluence and flux density.In addition,we obtain the timing solution of PSR J1709-43.Our analysis shows that PSRs J1919+1745,J1709-43,and J1649-4653 are potentially nulling pulsars or weak pulsars with sparse strong pulses.展开更多
Globular clusters harbor numerous millisecond pulsars,but long-period pulsars(P 100 ms)are rarely found.In this study,we employed a fast folding algorithm to analyze observational data from multiple globular clusters ...Globular clusters harbor numerous millisecond pulsars,but long-period pulsars(P 100 ms)are rarely found.In this study,we employed a fast folding algorithm to analyze observational data from multiple globular clusters obtained by the Five-hundredmeter Aperture Spherical radio Telescope(FAST),aiming to detect the existence of long-period pulsars.We estimated the impact of the median filtering algorithm in eliminating red noise on the minimum detectable flux density(S_(min))of pulsars.Subsequently,we successfully discovered two isolated long-period pulsars in M15 with periods approximately equal to 1.928451 and3.960716 s,respectively.On the P-˙P diagram,both pulsars are positioned below the spin-up line,suggesting a possible history of partial recycling in X-ray binary systems disrupted by dynamical encounters later on.According to timing results,these two pulsars exhibit remarkably strong magnetic fields.If the magnetic fields were weakened during the accretion process,then a short duration of accretion might explain the strong magnetic fields of these pulsars.展开更多
基金supported by the Major Science and Technology Program of Xinjiang Uygur Autonomous Region(grant no.2022A03013-4)the Zhejiang Provincial Natural Science Foundation of China(grant no.LY23A030001)+4 种基金the National SKA Program of China(grant no.2020SKA0120100,2022YFC2205201,2020SKA0120200)the Natural Science Foundation of Xinjiang Uygur Autonomous Region(grant no.2022D01D85)the National Natural Science Foundation of China(NSFC,grant Nos.12041304,12273100,and 12041303)the West Light Foundation of Chinese Academy of Sciences(grant no.WLFC 2021-XBQNXZ-027)the open program of the Key Laboratory of Xinjiang Uygur Autonomous Region(grant no.2020D04049)。
文摘Rotating Radio Transients(RRATs)are a relatively new subclass of pulsars that emit detectable radio bursts sporadically.We analyzed 10 RRATs observed using the Parkes telescope,with eight of these observed via the ultra-wide-bandwidth low-frequency(UWL)receiver.We measured the burst rate and produced integrated profiles spanning multiple frequency bands for three RRATs.We also conducted a spectral analysis on both integrated pulses and individual pulses of three RRATs.All of their integrated pulses follow a simple power law,consistent with the known range of pulsar spectral indices.Their average spectral indices of single pulses are-0.9,-1.2,and-1.0 respectively,which are within the known range of pulsar spectral indices.Additionally,we find that the spreads of single-pulse spectral indices for these RRATs(ranging from-3.5 to+0.5)are narrower compared to what has been observed in other RRATs.Notably,the average spectral index and scatter of single pulses are both relatively small.For the remaining five RRATs observed at the UWL receiver,we also provide the upper limits on fluence and flux density.In addition,we obtain the timing solution of PSR J1709-43.Our analysis shows that PSRs J1919+1745,J1709-43,and J1649-4653 are potentially nulling pulsars or weak pulsars with sparse strong pulses.
基金supported by the National Natural Science Foundation of China(Grant Nos.11988101,12103013,12041303,U2031117,12373109,and 12103069)the National SKA Program of China(Grant Nos.2020SKA0120200,2022SKA0130100,and2022SKA0130104)+2 种基金the National Key Research and Development Program of China(Grant No.2023YFB4503300)the Foundation of Science and Technology of Guizhou Province(Grant No.(2021)023)the Foundation of Guizhou Provincial Education Department(Grant Nos.KY(2020)003,and KY(2023)059)。
文摘Globular clusters harbor numerous millisecond pulsars,but long-period pulsars(P 100 ms)are rarely found.In this study,we employed a fast folding algorithm to analyze observational data from multiple globular clusters obtained by the Five-hundredmeter Aperture Spherical radio Telescope(FAST),aiming to detect the existence of long-period pulsars.We estimated the impact of the median filtering algorithm in eliminating red noise on the minimum detectable flux density(S_(min))of pulsars.Subsequently,we successfully discovered two isolated long-period pulsars in M15 with periods approximately equal to 1.928451 and3.960716 s,respectively.On the P-˙P diagram,both pulsars are positioned below the spin-up line,suggesting a possible history of partial recycling in X-ray binary systems disrupted by dynamical encounters later on.According to timing results,these two pulsars exhibit remarkably strong magnetic fields.If the magnetic fields were weakened during the accretion process,then a short duration of accretion might explain the strong magnetic fields of these pulsars.