We present and analyse a catalogue of 233 pulsars with proper motion measurements. The sample contains a wide variety of pulsars including recycled objects and those associated with globular clusters or supernova remnants. After taking the most precise proper motions for those pulsars for which multiple measurements are available, the majority of the proper motions (58 per cent) are derived from pulsar timing methods, 41 per cent using interferometers and the remaining 1 per cent using optical telescopes. Many of the one-dimensional (1D) and two-dimensional (2D) speeds (referring to speeds measured in one coordinate only and the magnitudes of the transverse velocities, respectively) derived from these measurements are somewhat lower than earlier estimates because of the use of the most recent electron density model in determining pulsar distances. The mean 1D speeds for the normal and recycled pulsars are 152(10) and 54(6) km s −1 , respectively. The corresponding mean 2D speeds are 246(22) and 87(13) km s −1 . PSRs B2011+38 and B2224+64 have the highest inferred 2D speeds of ∼1600 km s −1 .W estudy the mean speeds for different subsamples and find that, in general, they agree with previous results. Applying a novel deconvolution technique to the sample of 73 pulsars with characteristic ages less than 3 Myr, we find the mean threedimensional (3D) pulsar birth velocity to be 400(40) km s −1 . The distribution of velocities is well described by a Maxwellian distribution with 1D rms σ = 265 km s −1 . There is no evidence for a bimodal velocity distribution. The proper motions for PSRs B1830−08 and B2334+61 are consistent with their proposed associations with the supernova remnants W41 and G114.3+0.3, respectively. Ke yw ords: stars: kinematics ‐ pulsars: general.

A statistical study of 233 pulsar proper motions

Formation and evolution of binary and millisecond radio pulsars

There is a wide range of fundamental physical problems directly related to how pulsars function. Some of these are independent of the specific pulsar mechanism. Others relate directly to the physics of the pulsar and already shed some light on the properties of matter at high density (\ensuremath{\sim}${10}^{15}$ g/cc) and in strong magnetic fields (\ensuremath{\sim}${10}^{12}$ G). Pulsars are assumed to be rotating neutron stars surrounded by strong magnetic fields and energetic particles. It is somewhere within this "magnetosphere" that the pulsar action is expected to take place. Currently there has been considerable difficulty in formulating an entirely self-consistent theory of the magnetospheric behavior and there may be rapid revisions in the near future, which is all the more surprising since many of the issues involve "elementary" problems in electromagnetism. One interesting discovery is that charge-separated plasmas apparently can support stable static discontinuities.

Theory of pulsar magnetospheres

We investigate the birth and evolution of Galactic isolated radio pulsars. We begin by estimating their birth space velocity distribution from proper-motion measurements of Brisken and coworkers. We find no evidence for multimodality of the distribution and favor one in which the absolute one-dimensional velocity components are exponentially distributed and with a three-dimensional mean velocity of 380 km s-1. We then proceed with a Monte Carlo-based population synthesis, modeling the birth properties of the pulsars, their time evolution, and their detection in the Parkes and Swinburne Multibeam surveys. We present a population model that appears generally consistent with the observations. Our results suggest that pulsars are born in the spiral arms, with a galactocentric radial distribution that is well described by the functional form proposed by Yusifov & Kucuk, in which the pulsar surface density peaks at radius ~3 kpc. The birth spin period distribution extends to several hundred milliseconds, with no evidence of multimodality. Models that assume the radio luminosities of pulsars to be independent of the spin periods and period derivatives are inadequate, as they lead to the detection of too many old simulated pulsars in our simulations. Dithered radio luminosities proportional to the square root of the spin-down luminosity accommodate the observations well and provide a natural mechanism for the pulsars to dim uniformly as they approach the death line, avoiding an observed pileup on the latter. There is no evidence for significant torque decay (due to magnetic field decay or otherwise) over the lifetime of the pulsars as radio sources (~100 Myr). Finally, we estimate the pulsar birthrate and total number of pulsars in the Galaxy.

https://iopscience.iop.org/article/10.1086/501516/pdf

Birth and Evolution of Isolated Radio Pulsars

We infer the velocity distribution of radio pulsars based on large-scale 0.4 GHz pulsar surveys. We do so by modelling evolution of the locations, velocities, spins, and radio luminosities of pulsars; calculating pulsed flux according to a beaming model and random orientation angles of spin and beam; applying selection effects of pulsar surveys; and comparing model distributions of measurable pulsar properties with survey data using a likelihood function. The surveys analyzed have well-defined characteristics and cover approx. 95% of the sky. We maximize the likelihood in a 6-dimensional space of observables P, dot-P, DM, absolute value of b, mu, F (period, period derivative, dispersion measure, Galactic latitude, proper motion, and flux density). The models we test are described by 12 parameters that characterize a population's birth rate, luminosity, shutoff of radio emission, birth locations, and birth velocities. We infer that the radio beam luminosity (i) is comparable to the energy flux of relativistic particles in models for spin-driven magnetospheres, signifying that radio emission losses reach nearly 100% for the oldest pulsars; and (ii) scales approximately as E(exp 1/2) which, in magnetosphere models, is proportional to the voltage drop available for acceleration of particles. We find that a two-component velocity distribution with characteristic velocities of 90 km/ s and 500 km/ s is greatly preferred to any one-component distribution; this preference is largely immune to variations in other population parameters, such as the luminosity or distance scale, or the assumed spin-down law. We explore some consequences of the preferred birth velocity distribution: (1) roughly 50% of pulsars in the solar neighborhood will escape the Galaxy, while approx. 15% have velocities greater than 1000 km/ s (2) observational bias against high velocity pulsars is relatively unimportant for surveys that reach high Galactic absolute value of z distances, but is severe for spatially bounded surveys; (3) an important low-velocity population exists that increases the fraction of neutron stars retained by globular clusters and is consistent with the number of old objects that accrete from the interstellar medium; (4) under standard assumptions for supernova remnant expansion and pulsar spin-down, approx. 10% of pulsars younger than 20 kyr will appear to lie outside of their host remnants. Finally, we comment on the ramifications of our birth velocity distribution for binary survival and the population of inspiraling binary neutron stars relevant to some GRB models and potential sources for LIGO.

/pdf/the-velocity-distribution-of-isolated-radio-pulsars-5g0vpxnb0l.pdf

The Velocity distribution of isolated radio pulsars

/pdf/the-second-molonglo-pulsar-survey-discovery-of-155-pulsars-2zj9wkaqep.pdf

The second Molonglo pulsar survey – discovery of 155 pulsars

/pdf/supernova-remnant-candidates-in-the-small-magellanic-cloud-5d9lfifckx.pdf

Supernova remnant candidates in the Small Magellanic Cloud

/pdf/an-unusual-pulsar-psr-0826-34-3zpw5k3u9d.pdf

An unusual pulsar - PSR 0826-34.

Timing parameters are presented for 59, mostly southern, pulsars derived from observations using the Molonglo Observatory Synthesis Telescope over about 2.4 yr from 1986 to 1988. For 45 of the pulsars, either the positions or the period parameters are more accurate than those previously available. Comparisons of the new and previously published parameters show good agreement in most cases. However, several apparently significant position changes are obtained and, in six cases at least, these can be interpreted as proper motions. Significant changes in period parameters are also observed in several pulsars, and evidence is found for one or more large glitches in the period of PSR 1641 - 45

/pdf/timing-parameters-for-59-pulsars-10jb06te4z.pdf

Timing parameters for 59 pulsars

L'exploration d'une zone le long du plan galactique sud (P=255° a P=360°, b=±1°) a ete effectuee par le radiotelescope de Molonglo pour la recherche de pulsars millisecondes. Un total de 10 pulsars ont ete detectes dont un nouveau pulsar, PSR 0906-49 de periode 106 ms, mais aucun pulsar milliseconde n'a ete decouvert

/pdf/a-survey-for-millisecond-pulsars-at-molonglo-4ctqaxj7ri.pdf

J. M. Durdin

Papers

The second Molonglo pulsar survey – discovery of 155 pulsars

Supernova remnant candidates in the Small Magellanic Cloud

An unusual pulsar - PSR 0826-34.

Timing parameters for 59 pulsars

A survey for millisecond pulsars at Molonglo