S. D. Bates, S. Johnston, D. R. Lorimer, M. Kramer, A. Possenti, M. Burgay, B. Stappers, M. J. Keith, A. Lyne, M. Bailes, M. A. McLaughlin, J. T. O'Brien, G. Hobbs
A survey of the Galactic plane in the region $-60\degree \leq l \leq 30\degree$, $|b| \leq 0.25\degree$ was carried out using the seven-beam Parkes Methanol Multibeam (MMB) receiver, which operates at a frequency of 6.5 GHz. Three pulsars were discovered, and 16 previously known pulsars detected. In this paper we present two previously-unpublished discoveries, both with extremely high dispersion measures, one of which is very close, in angular distance, to the Galactic centre. The survey data also contain the first known detection, at radio frequencies, of the radio magnetar PSR J1550-5418. Our survey observation was made 46 days prior to that previously published and places constraints on the beginning of pulsed radio emission from the source.
The detection of only three previously undiscovered pulsars argues that there are few pulsars in the direction of the inner Galaxy whose flux density spectrum is governed by a flat power law. However, these pulsars would be likely to remain undetected at lower frequencies due to the large amount of scatter broadening which affects pulsars with high values of dispersion measure. Surveys with future telescopes at high observing frequencies will, therefore, play an important role in the discovery of pulsars at the Galactic centre. By simulating pulsar surveys of the Galaxy with Phase 1 SKA at frequencies of 1.4 GHz and 10 GHz, we find that high-frequency observations are the only way to discover and observe the Galactic-centre pulsar population.
We present the discovery of 37 pulsars from $\sim$ 20 years old archival data of the Parkes Multibeam Pulsar Survey using a new FFT-based search pipeline optimised for discovering narrow-duty cycle pulsars. When developing our pulsar search pipeline, we noticed that the signal-to-noise ratios of folded and optimised pulsars often exceeded that achieved in the spectral domain by a factor of two or greater, in particular for narrow duty cycle ones. Based on simulations, we verified that this is a feature of search codes that sum harmonics incoherently and found that many promising pulsar candida…
帕克斯多波束脉冲星巡天的再处理发现了五颗以前未知的脉冲星和几颗尚未确认的候选者。PSR J 0922 -52的周期为9.68 ms，DM为122.4 pc cm^-3。PSR J1147-66的周期为3.72 ms，DM为133.8 pc cm^-3。PSR J1227-6208的周期为34.53 ms，DM为362.6 pc cm^-3，处于一个6.7天的双星轨道上，桑顿等人在进行中的高分辨率帕克斯巡天中独立探测到了它，爱因斯坦@Home志愿者也在独立处理中探测到了它。PSR J1546-59的周期为7.80 ms，DM为168.3 pc cm^-3。PSR J1725-3853是一颗孤立的4.79 ms脉冲星，DM为158.2 pc cm^-3。这些候选人可能在早期的处理工作中被遗漏，因为他们的DM很高，周期很短，而且需要浏览的候选人数量很大。这些发现表明，在多波束勘测数据中，还有待发现更多的类星体。
We revisit the population of normal pulsars in the Galactic field in an `evolutionary' approach. By comparing the distributions of various parameters of synthetic pulsars detectable by the Parkes Multibeam Pulsar Survey, the Pulsar Arecibo L-band Feed Array Survey, and two Swinburne Multibeam surveys with those of the real pulsars detected by the same surveys, we find that a good and physically realistic model can be obtained by using a uniform distribution of the braking index in the range of 2.5 to 3.0, a uniform distribution of the cosine of the angle between the spin and the magnetic axis …
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…
The FAST-SETI Milky Way Globular Cluster Survey I: A Pilot Multibeam On-the-Fly Search of Five Globular Clusters at L-Band
Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University（北京师范大学前沿天文与天体物理研究所）；School of Physics and Astronomy, Beijing Normal University（北京师范大学物理与天文学院）；College of Computer and Information Engineering, Dezhou University（德州学院计算机与信息工程学院）；University of California, Berkeley（加州大学伯克利分校）；SETI Institute（SETI研究所）
The predicted nature of the candidate redback pulsar 3FGL\,J2039.6$-$5618 was recently confirmed by the discovery of $γ$-ray millisecond pulsations (Clark et al. 2020, hereafter Paper\,I), which identify this $γ$-ray source as \msp. We observed this object with the Parkes radio telescope in 2016 and 2019. We detect radio pulsations at 1.4\,GHz and 3.1\,GHz, at the 2.6ms period discovered in $γ$-rays, and also at 0.7\,GHz in one 2015 archival observation. In all bands, the radio pulse profile is characterised by a single relatively broad peak which leads the main $γ$-ray peak. At 1.4\,GHz we fo…
