Radio pulsar populations

Abstract

The goal of this article is to summarize the current state of play in the field of radio pulsar statistics. Simply put, from the observed sample of objects from a variety of surveys with different telescopes, we wish to infer the properties of the underlying sample and to connect these with other astrophysical populations (for example supernova remnants or X-ray binaries). The main problem we need to tackle is the fact that, like many areas of science, the observed populations are often heavily biased by a variety of selection effects. After a review of the main effects relevant to radio pulsars, I discuss techniques to correct for them and summarize some of the most recent results. Perhaps the main point I would like to make in this article is that current models to describe the population are far from complete and often suffer from strong covariances between input parameters. That said, there are a number of very interesting conclusions that can be made concerning the evolution of neutron stars based on current data. While the focus of this review will be on the population of isolated Galactic pulsars, I will also briefly comment on millisecond and binary pulsars as well as the pulsar content of globular clusters and the Magellanic Clouds.Comment: 16 pages, 6 figures, to appear in Proceedings of ICREA Workshop on The High-Energy Emission from Pulsars and their Systems, Sant Cugat, Spain, 2010 April 12-16 (Springer

The Galactic Millisecond Pulsar Population

“…Thanks to the current generation of large-scale pulsar surveys, we find ourselves in an era where we have large samples of both millisecond and normal pulsars and, in particular for millisecond pulsars, there are many opportunities to learn about the population of objects as a whole based upon the ones we see. The contributions by Keith, Ng, Lazarus and Lynch elsewhere in these proceedings provide the latest status of these searches, and further details can be found in Lorimer (2011). These discoveries are due to the modern surveys having low-noise receiver systems with a large fractional bandwidth and employing state-of-the-art digital data acquisition systems which are now close to optimal (e.g.…”

“…These selection effects include the inverse-square law, pulse dispersion and scattering, pulsar intermittency, interstellar scintillation and also binary motion. For further details of these effects, the interested reader is referred to earlier reviews on this subject (Lorimer 2009(Lorimer , 2011.…”

Testing the accretion-induced field-decay and spin-up model for recycled pulsars

“…The evolutionary precursors to recycled MSPs are widely believed to be pulsars in binaries with high magnetic fields (B ∼ 10 11 −10 13 G) and long spin periods (P ∼ a few seconds, Bhattacharya & van den Heuvel 1991;Liu et al 2007;Lorimer 2011). It is evident that the B and P of normal pulsars and recycled pulsars are correlated with the duration of the accretion phase and the total amount of accreted mass (Taam & van den Heuvel 1986;Shibazaki et al 1989;Wijers 1997).…”

Do pulsar radio fluxes violate the inverse-square law?

“…This model has also been used to explain the frequency spectrum of the Crab pulsar (Ardavan et al 2008b). However, the result of S09 has been disputed by the pulsar community (Lorimer 2011). If the pulsar flux varied more slowly than an inverse-square law, one would have discovered a large number of pulsars in M31 or M33, whereas no confirmed detections have been made (McLaughlin & Cordes 2003;Bhat et al 2011;Rubio-Herrera et al 2013).…”