Yi Feng, George Hobbs, Di Li, Shi Dai, Weiwei Zhu, Youling Yue, Pei Wang, Songbo Zhang, Lei Qian, Lei Zhang, Shuangqiang Wang, Chenchen Miao, Mao Yuan, Yongkun Zhang
Using the Five-hundred-meter Aperture Spherical radio Telescope (FAST), we have recorded 10^5 single pulses from PSR J1022+1001. We studied the polarization properties, their energy distribution and their times of arrival. This is only possible with the high sensitivity available using FAST. There is no indication that PSR~J1022+1001 exhibits giant pulse, nulling or traditional mode changing phenomena. The energy in the leading and trailing components of the integrated profile is shown to be correlated. The degree of both linear and circular polarization increases with the pulse flux density for individual pulses. Our data indicates that pulse jitter leads to an excess noise in the timing residuals of 67 ns when scaled to one hour, which is consistent with Liu et al. (2015). We have unsuccessfully trialled various methods to improve timing precision through the selection of specific single pulses. Our work demonstrates that FAST can detect individual pulses from pulsars that are observed in order to detect and study gravitational waves. This capability enables detailed studies, and parameterisation, of the noise processes that affect the sensitivity of a pulsar timing array.
Interstellar scattering causes broadening and distortion to the mean pulse profiles and polarization position angle (PPA) curves, especially to the pulse profiles observed at lower frequency. This paper has implemented a method to recover the pulse profiles and the PPA curves of five pulsars which have obvious scattered pulse profiles at lower frequency. It reports a simulation to show the scattering and descattering of pulse profiles and PPA curves. As a practical application, lower-frequency profiles and PPA curves of PSR 1356-60, PSR 1831-03, PSR 1838+04, PSR 1859+03, PSR 1946+35 are obtain…
More than 100 rotating radio transients (RRATs) have been discovered since 2006. However, it is unclear whether RRATs radiate in the nulling states. PSR J0628+0909 has been classified as an RRAT. In this paper, we study the single pulses and integrated pulse profile of PSR J0628+0909 to check whether we can detect pulsed radio emission in the nulling states. We also aim to study the polarization of the RRAT and its relationship to the general pulsar population. We used the Five-hundred-meter Aperture Spherical radio Telescope (FAST) to observe PSR J0628+0909 in the frequency range from 1.0 to …
We present radio observation of a millisecond pulsar PSR J0621+1002 using the Five-hundred-meter Aperture Spherical radio Telescope (FAST). The pulsar shows periodic pulse intensity modulations for both the first and the third pulse components. The fluctuation spectrum of the first pulse component has one peak of 3.0$\pm$0.1 pulse periods, while that of the third pulse component has two diffused peaks of 3.0$\pm$0.1 and 200$\pm$1 pulse periods. The single pulse timing analysis is carried out for this pulsar and the single pulses can be divided into two classes based on the post-fit timing resi…
We report the detection of giant pulse emission from PSR~B0950+08 in 12 hours of observations made simultaneously at 42~MHz and 74~MHz, using the first station of the Long Wavelength Array, LWA1. We detected 275 giant pulses (in 0.16\% of the pulse periods) and 465 giant pulses (0.27\%) at 42 and 74~MHz, respectively. The pulsar is weaker and produces less frequent giant pulses than at 100~MHz. Here, giant pulses are taken as having $\geq$ 10 times the flux density of an average pulse; their cumulative distribution of pulse strength follows a power law, with a index of $-$4.1 at 42~MHz and $-$…
Average radio pulse profile of a pulsar B in a double pulsar system PSR J0737-3039A/B exhibits an interesting behaviour. During the observation period between 2003 and 2009, the profile evolves from a single-peaked to a double-peaked form, following disappearance in 2008 indicating that the geodetic precession of the pulsar is a possible origin of such behaviour. The known pulsar beam models can be used to determine the geometry of PSR J0737-3039B in the context of the precession. We study how the fan-beam geometry performs in explaining the observed variations of the radio profile morphology.…
We have studied the variability of PSR J0529-6652, a radio pulsar in the LMC, using observations conducted at 1390 MHz with the Parkes 64-m telescope. PSR J0529-6652 is detectable as a single pulse emitter, with amplitudes that classify the pulses as giant pulses. This makes PSR J0529-6652 the second known giant pulse emitter in the LMC, after PSR B0540-69. The fraction of the emitted pulses detectable from PSR J0529-6652 at this frequency is roughly two orders of magnitude greater than it is for either PSR B0540-69 or the Crab pulsar (if the latter were located in the LMC). We have measured a…
We report on single-pulse observations of the Galactic Center magnetar PSR J1745$-$2900 that were made using the Parkes 64-m radio telescope with a central frequency of 3.1 GHz at five observing epochs between 2013 July and August. The shape of the integrated pulse profiles was relatively stable across the five observations, indicating that the pulsar was in a stable state between MJDs 56475 and 56514. This extends the known stable state of this pulsar to 6.8 months. Short term pulse shape variations were also detected. It is shown that this pulsar switches between two emission modes frequentl…
We report the emission variations in PSR J1047$-$6709 observed at 1369 MHz using the Parkes 64 m radio telescope. This pulsar shows two distinct emission states: a weak state and a bright emission state. We detected giant pulses (GPs) in the bright state for the first time. We found 75 GPs with pulse width ranging from 0.6 to 2.6 ms. The energy of GPs follows a power-law distribution with the index $α=-3.26\pm0.22$. The peak flux density of the brightest GP is 19 Jy which is 110 times stronger than the mean pulse profile. The polarization properties of the average profile of GPs are similar to…
We have detected sporadic, bright, short-duration radio pulses from PSR J0901$-$4624. These pulses are emitted simultaneously with persistent, periodic emission that dominates the flux density when averaging over many periods of the pulsar. The bright pulses have energies that are consistent with a power-law distribution. The integrated profile of PSR J0901$-$4624 is highly polarized and shows four distinct components. The bright pulses appear to originate near the magnetic pole of the pulsar and have polarization properties unlike that of the underlying emission at the same pulse phase. We co…
PSR J1825$-$0935 (PSR B1822$-$09) switches between radio-quiet (Q-mode) and radio-bright (B-mode) modes. The Q-mode is known to have a periodic fluctuation that modulates both the interpulse and the main pulse with the same period. Earlier investigators argued that the periodic Q-mode modulation is associated with drifting subpulses. We report on single-pulse observations of PSR J1825$-$0935 that were made using the Parkes 64-m radio telescope with a central frequency of 1369 MHz. The high-sensitivity observations revealed that the periodic Q-mode modulation is in fact a periodic longitude-sta…
Pulse arrival time measurements over fourteen years with the Nanshan 25-m and Parkes 64-m radio telescopes have been used to determine the average profile and timing properties for PSR J1757$-$2421 (B1754$-$24). Analysis of the radio profile data shows a large variation of spectral index across the profile and an unusual increase in component separation with increasing frequency. The timing observations show that PSR B1754$-$24 underwent a large glitch with a fractional increase in spin frequency of $Δν_{\rm g}/ν\sim 7.8\times10^{-6}$ in May 2011. At the time of the glitch there was a large pe…
Many radio pulsars have stable pulse profiles, but some exhibit mode changing where the profile switches between two or more quasi-stable modes of emission. So far, these effects had only been seen in relatively slow pulsars, but we show here that the pulse profile of PSR B1957+20, a millisecond pulsar, switches between two modes, with a typical time between mode changes of only $1.7$ s (or $\sim\!1000$ rotations), the shortest observed so far. The two modes differ in both intensity and polarization, with relatively large differences in the interpulse and much more modest ones in the main puls…
We report the detection of giant pulse emission from PSR B0950+08 in 24 hours of observations made at 39.4 MHz, with a bandwidth of 16 MHz, using the first station of the Long Wavelength Array, LWA1. We detected 119 giant pulses from PSR B0950+08 (at its dispersion measure), which we define as having SNRs at least 10 times larger than for the mean pulse in our data set. These 119 pulses are 0.035% of the total number of pulse periods in the 24 hours of observations. The rate of giant pulses is about 5.0 per hour. The cumulative distribution of pulse strength $S$ is a steep power law, $N(>S)\pr…
The interstellar medium scatters radio waves which causes pulsars to scintillate. For intrinsically short bursts of emission, the observed signal should be a direct measurement of the impulse response function. We show that this is indeed the case for giant pulses from PSR B1957+20: from baseband observations at 327 MHz, we demonstrate that the observed voltages of a bright pulse allow one to coherently descatter nearby ones. We find that while the scattering timescale is $12.3\,μ$s, the power in the descattered pulses is concentrated within a span almost two orders of magnitude shorter, of $\…
Pulsars are the "lighthouses" in the universe. Periodic pulses with the duty-cycle ~10% are detected when the radio beam of the rotating pulsar sweeps across the telescope. In this report, the 160 min-data of a nearby pulsar, PSR B0950+08, observed with the Five-hundred-meter Aperture Spherical radio Telescope (FAST) is analysed. Thanks to the extremely high sensitivity of FAST, it is found that the radiation of PSR B0950+08 could be detected over the entire pulse period. To investigate the radiative characteristics of the pulsar' "bridge emission", a function, $Θ$(n), is defined to reveal the…
We report on the properties of strong pulses from PSR B0656+14 by analyzing the data obtained using Urumqi 25-m radio telescope at 1540 MHz from August 2007 to September 2010. In 44 hrs of observational data, a total of 67 pulses with signal-to-noise ratios above a 5-σ threshold were detected. The peak flux densities of these pulses are 58 to 194 times that of the average profile, and the pulse energies of them are 3 to 68 times that of the average pulse. These pulses are clustered around phases about 5 degrees ahead of the peak of the average profile. Comparing with the width of the average p…
Single-pulse reanalysis of the 2024 Vela glitch and new observations of PSR~J0437$-$4715 and PSR~J1644$-$4559
Center for Computational Relativity and Gravitation, Rochester Institute of Technology（罗切斯特理工学院相对论与引力计算中心）；Golisano College of Computing and Information Sciences, Rochester Institute of Technology（罗切斯特理工学院戈利萨诺计算机与信息科学学院）；Instituto Argentino de Radioastronomía (CCT La Plata, CONICET（阿根廷射电天文研究所）；CICPBA（科尔多瓦大学数学、天文学、物理与计算学院）；UNLP)（拉普拉塔国立大学天文与地球物理科学学院）；Facultad de Matemática, Astronomía, Física y Computación, UNC；Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata
We have observed PSR~B1534+12 (J1537+1155), a pulsar with a neutron star companion, using the Five-hundred-meter Aperture Spherical radio Telescope (FAST). We found that this pulsar shows two distinct emission states: a weak state with a wide pulse profile and a burst state with a narrow pulse profile. The weak state is always present. We cannot, with our current data, determine whether the pulse energy of the weak state follows a normal or a log-normal distribution. The burst state energy distribution follows a power-law. The amplitude of the single pulse emission in the burst state varies si…
The first station of the Long Wavelength Array (LWA1) was used to study PSR~B0031-07 with simultaneous observations at 38 and 74~MHz. We found that 158 (0.35\%) of the observed pulses at 38~MHz and 221 (0.49\%) of the observed pulses at 74~MHz qualified as giant pulses in a total of 12 hours of observations. Giant pulses are defined as having flux densities of a factor of $\geq$ 90 times that of an average pulse at 38~MHz and $\geq$ 80 times that of an average pulse at 74~MHz. The cumulative distribution of pulse strength follows a power law, with an index of $-$4.2 at 38~MHz and $-$4.9 at 74~…
We present here the detection of giant-pulse emission from PSR B0950+08, a normal-period pulsar. The observations, made at 103 MHz and lasting for about ten months, have shown on a number of days the frequency of occurrence of giant pulses to be the highest among the known pulsars. The flux--density level of successive giant pulses fluctuates rapidly and their occurrence rates within a day's observations as well as between neighboring days show large variations. While on some days PSR B0950+08 shows a large number of giant pulses, there are other days when it shows only "quasi-nulls" with no d…
With the largest dish Five-hundred-meter Aperture Spherical radio Telescope (FAST), both the mean and single pulses of PSR B2016$+$28, especially including the single-pulse structure, are investigated in detail in this study. The mean pulse profiles at different frequencies can be well fitted in a conal model, and the peak separation of intensity-dependent pulse profiles increases with intensity. The integrated pulses are obviously frequency dependent (pulse width decreases by $\sim\,20\%$ as frequency increases from 300 MHz to 750 MHz), but the structure of single pulses changes slightly (the…
In this paper, we report radio observations of the Galactic Center magnetar PSR J1745-2900 at six epochs between June and October, 2014. These observations were carried out using the new Shanghai Tian Ma Radio Telescope at a frequency of 8.6 GHz. Both the flux density and integrated profile of PSR J1745-2900 show dramatic changes from epoch to epoch showing that the pulsar was in its "erratic" phase. On MJD 56836, the flux density of this magnetar was about 8.7 mJy, which was ten times large than that reported at the time of discovery, enabling a single-pulse analysis. The emission is dominate…
PSR B1821$-$24 is a solitary millisecond pulsar (MSP) which radiates multi-wavelength pulsed photons. It has complex radio, X-ray and $γ$-ray pulse profiles with distinct peak phase-separations that challenge the traditional caustic emission models. Using the single-pole annular gap model with suitable magnetic inclination angle ($α=40^\circ$) and viewing angle ($ζ=75^\circ$), we managed to reproduce its pulse profiles of three wavebands. It is found that the middle radio peak is originated from the core gap region at high altitudes, and the other two radio peaks are originated from the annula…
We present deep XMM-Newton EPIC spectroscopic and timing X-ray observations of the nearby solitary radio millisecond pulsar, PSR J0030+0451. Its emission spectrum in the 0.1-10 keV range is found to be remarkably similar to that of the nearest and best studied millisecond pulsar, PSR J0437-4715, being well described by a predominantly thermal two-temperature model plus a faint hard tail evident above ~2 keV. The pulsed emission in the 0.3-2 keV band is characterized by two broad pulses with pulsed fraction ~60-70%, consistent with a mostly thermal origin of the X-rays only if the surface polar…
We used the Fourier decomposition technique to investigate the stability of the X-ray pulse profile of a young pulsar PSR B1509-58 by studying the relative amplitudes and the phase differences of its harmonic components with respect to the fundamental using data from the Rossi X-Ray Timing Explorer. Like most young rotation powered pulsars, PSR B1509-58 has a high spin down rate. It also has less timing noise allowing accurate measurement of higher order frequency derivatives which in turn helps in study of the physics of pulsar spin down. Detailed investigation of pulse profiles over the year…
We report the discovery of soft X-ray pulsations from the nearby millisecond pulsar PSR J1231$-$1411 using NICER. The pulsed emission is characterized by a broad and asymmetric main pulse and a much fainter secondary interpulse, with a total pulsed count rate of 0.055 c s$^{-1}$ in the 0.35-1.5 keV band. We analyzed Fermi LAT data to update the pulse timing model covering 10 years of data and used that model to coherently combine NICER data over a year of observations. Spectral modeling suggests that the flux is dominated by thermal emission from a hot spot (or spots) on the neutron star surfa…
The transitional millisecond pulsar PSR\,J1023+0038 is the first millisecond pulsar discovered to emit UV and optical pulses. Here we present the results of the UV and X-ray phase-resolved timing analysis of observations performed with the Hubble Space Telescope, \textit{XMM-Newton} and NuSTAR satellites between 2014 and 2021. Ultraviolet pulsations are detected in the high luminosity mode and disappear during low and flaring modes, similar to what is observed in the X-ray band. In the high mode, we find variability in both the UV and X-ray pulse amplitudes. The root mean square pulsed amplitu…
One of the tenets of the radio pulsar observational picture is that the integrated pulse profiles are constant with time. This assumption underpins much of the fantastic science made possible via pulsar timing. Over the past few years, however, this assumption has come under question with a number of pulsars showing pulse shape changes on a range of timescales. Here, we show the dramatic appearance of a bright component in the pulse profile of PSR J0738-4042 (B0736-40). The component arises on the leading edge of the profile. It was not present in 2004 but strongly present in 2006 and all obse…
We report on the detection of extreme giant pulses (GPs) from one of the oldest-known pulsars, the highly variable PSR B0950+08, with the Amsterdam-ASTRON Radio Transient Facility And Analysis Centre (AARTFAAC), a parallel transient detection instrument operating as a subsystem of the LOw Frequency ARray (LOFAR). During processing of our Northern Hemisphere survey for low-frequency radio transients, a sample of 275 pulses with fluences ranging from 42 to 177 kJy ms were detected in one-second snapshot images. The brightest pulses are an order of magnitude brighter than those previously reporte…
Point-like Off-pulse GeV Emission from the Millisecond Pulsar PSR J0437-4715
Tsung-Dao Lee Institute, Shanghai Jiao Tong University（汤川研究所，上海交通大学）；State Key Laboratory of Dark Matter Physics, Shanghai Jiao Tong University（暗物质物理全国重点实验室，上海交通大学）
Aims. To make a detailed study of the nulling and subpulse drifting in PSR J1727$-$2739 for investigation of its radiation properties. Methods. The observations were carried out on 20 March, 2004 using the Parkes 64-m radio telescope, with a central frequency of 1518 MHz. A total of 5568 single pulses were analysed. Results. This pulsar shows well defined nulls with lengths lasting from 6 to 281 pulses and separated by burst phases ranging from 2 to 133 pulses. We estimate a nulling fraction of around 68\%. No emission in the average pulse profile integrated over all null pulses is detected wi…
Cross-Comparison of Sampling Algorithms for Pulse Profile Modeling of PSR J0740+6620
Anton Pannekoek Institute for Astronomy, University of Amsterdam（阿姆斯特丹大学安东·潘内库克天文学研究所）；Department of Physics, University of Helsinki（赫尔辛基大学物理系）；Max Planck Institute for Extraterrestrial Physics（马克斯·普朗克地外物理学研究所）
We presented timing results of PSR B2035+36 using ~9-yr observations with the Nanshan 25-m radio telescope. PSR B2035+36 was reported to exhibit significant changes in pulse profile correlated with spin-down state variations. We found that the pulsar underwent a glitch with a jump in the frequency of $Δν\sim12.4(5)\, \rm nHz$ around MJD 52950. Unusually, the spin-down rate increased persistently over $800$ days after the glitch, and the average spin-down rate of post-glitch was about $9.6\%$ larger than pre-glitch. Accompanied with the glitch activity, pulse profile became narrower. The pulsar…
Single-pulse studies are important to understand the pulsar emission mechanism and the noise floor in precision timing. We study total intensity and polarimetry properties of three bright millisecond pulsars - PSRs J1022+1001, J1713+0747, and B1855+09 - that have detectable single pulses at multiple frequencies. We report for the first time the detection of single pulses from PSRs J1022+1001 and J1713+0747 at 4.5 GHz. In addition, for those two pulsars the fraction of linear polarization in the average profile is significantly reduced at 4.5 GHz, compared to 1.38 GHz, which could support the e…
We present results from observations of the Galactic Center magnetar, PSR J1745-2900, at 2.3 and 8.4 GHz with the NASA Deep Space Network 70 m antenna, DSS-43. We study the magnetar's radio profile shape, flux density, radio spectrum, and single pulse behavior over a ~1 year period between MJDs 57233 and 57621. In particular, the magnetar exhibits a significantly negative average spectral index of $\langleα\rangle$ = -1.86 $\pm$ 0.02 when the 8.4 GHz profile is single-peaked, which flattens considerably when the profile is double-peaked. We have carried out an analysis of single pulses at 8.4 …
The Double Pulsar, PSR J$0737$$-$$3039$A/B, is a unique system in which both neutron stars have been detected as radio pulsars. As shown in Ferdman et al., there is no evidence for pulse profile evolution of the A pulsar, and the geometry of the pulsar was fit well with a double-pole circular radio beam model. Assuming a more realistic polar cap model with a vacuum retarded dipole magnetosphere configuration including special relativistic effects, we create synthesized pulse profiles for A given the best-fit geometry from the simple circular beam model. By fitting synthesized pulse profiles to…
Millisecond pulsars (MSPs) are known as highly stable celestial clocks. Nevertheless, recent studies have revealed the unstable nature of their integrated pulse profiles, which may limit the achievable pulsar timing precision. In this paper, we present a case study on the pulse profile variability of PSR J1022+1001. We have detected approximately 14,000 sub-pulses (components of single pulses) in 35-hr long observations, mostly located at the trailing component of the integrated profile. Their flux densities and fractional polarisation suggest that they represent the bright end of the energy d…
PSR J0205+6449 is a young rotation-powered pulsar in SNR 3C 58. It is one of only three young (<10,000 year old) pulsars which are so far detected in the radio and the classical X-ray bands, as well as at hard X-rays above 20 keV and at high-energy (>100 MeV) $γ$-rays. The other two young pulsars are the Crab and PSR B1509-58. Our aim is to derive the timing and spectral characteristics of PSR J0205+6449 over the broad X-ray band from ~0.5 to ~270 keV. We used all publicly available RXTE observations of PSR J0205+6449 to first generate accurate ephemerides over the period September 30, 2000 - …
In this study, we report on a detailed single pulse analysis of the radio emission from the pulsar J1401$-$6357 (B1358$-$63) based on data observed with the ultrawideband low-frequency receiver on the Parkes radio telescope. In addition to a weak leading component, the integrated pulse profile features a single-humped structure with a slight asymmetry. The frequency evolution of the pulse profile is studied. Well-defined nulls, with an estimated nulling fraction greater than 2\%, are present across the whole frequency band. No emission is detected with significance above 3$σ$ in the average pu…
PSR J0540$-$6919 is the second-most energetic radio pulsar known and resides in the Large Magellanic Cloud. Like the Crab pulsar it is observed to emit giant radio pulses (GPs). We used the newly-commissioned PTUSE instrument on the MeerKAT radio telescope to search for GPs across three observations. In a total integration time of 5.7 hrs we detected 865 pulses above our 7$σ$ threshold. With full polarisation information for a subset of the data, we estimated the Faraday rotation measure, $\rm{RM}=-245.8 \pm 1.0$ rad m$^{-2}$ toward the pulsar. The brightest of these pulses is $\sim$ 60% linea…
Single pulses from radio pulsars contain a wealth of information about emission and propagation in the magnetosphere and insight into their timing properties. It was recently demonstrated that single-pulse emission is responsible for limiting the timing stability of the brightest of millisecond pulsars. We report on an analysis of more than a million single-pulses from PSR J0437-4715 and present various statistical properties such as the signal-to-noise ratio (S/N) distribution, timing and polarimetry of average profiles integrated from subpulses with chosen S/N cut-offs, modulation properties…
We show the results of microsecond resolution radio data analysis focused on flux measurements of single pulses of PSR B1133+16. The data were recorded at 4.85 GHz and 8.35 GHz with 0.5 GHz and 1.1 GHz bandwidth, respectively, using Radio Telescope Effelsberg (MPIfR). The most important conclusion of the analysis is, that the strongest single pulse emission at 4.85 GHz and 8.35 GHz contributes almost exclusively to the trailing part of the leading component of the pulsar mean profile, whereas studies at lower frequencies report that the contribution is spread almost uniformly covering all phas…
The radio-quiet pulsar PSR J2021+4026 is mostly known because it is the only rotation-powered pulsar that shows variability in its γ-ray emission. Using XMM-Newton archival data, we first confirmed that its flux is steady in the X-ray band, and then we showed that both the spectral and timing X-ray properties, i.e. the narrow pulse profile, the high pulsed fraction of 80-90% and its dependence on the energy, can be better reproduced using a magnetized atmosphere model instead of a simply blackbody. With a maximum likelihood analysis in the energy-phase space, we inferred that the pulsar has, i…
We present two years of Neutron star Interior Composition Explorer (NICER) X-ray observations of three energetic rotation-powered millisecond pulsars (MSPs): PSRs B1937+21, B1821-24, and J0218+4232. We fit Gaussians and Lorentzians to the pulse profiles for different energy sub-bands of the soft X-ray regime to measure the energy dependence of pulse separation and width. We find that the separation between pulse components of PSR J0218+4232 decreases with increasing energy at $\gt 3σ$ confidence. The 95% upper limit on pulse separation evolution for PSRs B1937+21 and B1821-24 is less than 2 mi…
We have studied 4265 giant pulses (GPs) from the millisecond pulsar B1937+21; the largest-ever sample gathered for this pulsar, in observations made with the Large European Array for Pulsars. The pulse energy distribution of GPs associated with the interpulse are well-described by a power law, with index $α= -3.99 \pm 0.04$, while those associated with the main pulse are best-described by a broken power law, with the break occurring at $\sim7$ Jy $μ$s, with power law indices $α_{\text{low}} = -3.48 \pm 0.04$ and $α_{\text{high}} = -2.10 \pm 0.09$. The modulation indices of the GP emission are …
The Rossi X-ray Timing Explorer ({\sl RXTE}) has made hundreds of observations on three famous young pulsars (PSRs) B0531+21 (Crab), B1509-58, and B0540-69. Using the archive {\sl RXTE} data, we have studied the phase-resolved spectral properties of these pulsars in details. The variation of the X-ray spectrum with phase of PSR B0531+21 is confirmed here much more precisely and more details are revealed than the previous studies: the spectrum softens from the beginning of the first pulse, turns to harden right at the pulse peak and becomes the hardest at the bottom of the bridge, softens gradu…
Single pulses preserve information about the pulsar radio emission and propagation in the pulsar magnetosphere, and understanding the behaviour of their variability is essential for estimating the fundamental limit on the achievable pulsar timing precision. Here we report the findings of our analysis of single pulses from PSR J1713+0747 with data collected by the Large European Array for Pulsars (LEAP). We present statistical studies of the pulse properties that include distributions of their energy, phase and width. Two modes of systematic sub-pulse drifting have been detected, with a periodi…
Single-Pulse Study of the Pseudo-nulling Pulsar PSR J1820-0509 Based on FAST Observations
Guizhou Normal University（贵州师范大学）；Huazhong University of Science and Technology（华中科技大学）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；Tsinghua University（清华大学）；Beijing Normal University（北京师范大学）；Qilu Normal University（齐鲁工业大学）
Radio timing observations of the high-magnetic-field pulsar PSR J1718-3718 have shown that it suffered a large glitch with Dnu_g/nu = (33.25 +/- 0.01) x 10^{-6} between 2007 September (MJD 54336) and 2009 January (MJD 54855). This is the largest pulsar glitch ever observed. As is common, there was a small increase in braking torque at the time of the glitch but, unlike all other pulsars, the braking torque has continued to increase over the two years since the glitch. Polarization observations show that the mean pulse profile has about 30% linear polarization with a smooth change of position a…
