The Velocity Distribution of Isolated Radio Pulsars

By Z. Arzoumanian, D. Chernoff, J. Cordes. 2001

473 citations recorded by the source corpus.

We infer the velocity distribution of radio pulsars based on large-scale 0.4 GHz pulsar surveys. We do so by modeling the 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 ~95% of the sky. We maximize the likelihood in a six-dimensional space of observables P, , DM, |b|, μ, and F (period, period derivative, dispersion measure, Galactic latitude, proper motion, and flux density, respectively). 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 (1) 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 (2) scales approximately as 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 and 500 km s-1 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 ~15% have velocities greater than 1000 km s-1; (2) observational bias against high-velocity pulsars is relatively unimportant for surveys that reach high Galactic |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, ~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.

Subfields: Astronomy and Astrophysics, Instrumentation, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/c9728046b3cbc4d0fae231fc04aeea8689728102

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Citations in the corpus

High-Altitude Emission from Pulsar Slot Gaps: The Crab Pulsar (2008, methodology): “The particular description we adopt is from Gonthier et al. (2004) and is based onwork of Arzoumanian et al. (2002), who fit average-pulse profiles of a small collection of pulsars at 400MHz to a core and single cone beam model based on the work of Rankin (1993).”
Compact Object Modeling with the StarTrack Population Synthesis Code (2005, methodology): “In addition, more recent (Arzoumanian et al. 2002; Hobbs et al. 2005) natal kick distributions are used here as compared to Lyne & Lorimer (1994) in BSE.”
Neutron Star Kicks by the Gravitational Tug-boat Mechanism in Asymmetric Supernova Explosions: Progenitor and Explosion Dependence (2016, background): “…breakup velocities of close double-star systems) and by the orbital parameters and spin orientations of NSs in binary systems (e.g., Harrison et al. 1993; Kaspi et al. 1996; Lyne & Lorimer 1994; Fryer et al. 1998; Lai et al. 2001; Arzoumanian et al. 2002; Chatterjee et al. 2005; Hobbs et al. 2005).”
Multidimensional supernova simulations with approximative neutrino transport. II. Convection and the (2007, background): “…stars move through interstellar space with velocities much higher than those of their progenitors (e.g., Cordes et al. 1993; Lyne & Lorimer 1994; Hansen & Phinney 1997; Arzoumanian et al. 2002; Zou et al. 2005; Chatterjee et al. 2005; Hobbs et al. 2005), in some cases with more than 1000 km s−1.”
Massive runaway and walkaway stars (2018, background): “…the CC of low-mass iron (or oxygen-neon-magnesium) cores produces small natal kicks, possibly resulting in a bi-modal kick distribution (Katz 1975; Arzoumanian et al. 2002; Pfahl et al. 2002; Podsiadlowski et al. 2004; Knigge et al. 2011; Beniamini & Piran 2016; Tauris et al. 2017; Verbunt &…”
The cosmic merger rate of neutron stars and black holes (2018, background): “…suggest a bimodal velocity distribution, with a first peak at low velocities (e.g. ∼ 0 km s−1 according to Fryer et al. 1998 or ∼ 90 km s−1 according to Arzoumanian et al. 2002) and a second peak at high velocities (> 600 km s−1 according to Fryer et al. 1998 or ∼ 500 km s−1 for Arzoumanian et…”
Explosion mechanism, neutrino burst and gravitational wave in core-collapse supernovae (2005, background): “300 − 400 km/s [236, 227], with highest values greater than 1000 km/s [19]), which are most likely imparted to the neutron star by a kick at the moment of the explosion.”
Multidimensional supernova simulations with approximative neutrino transport. I. Neutron star kicks and the anisotropy of neutrino-driven explosions in two spatial dimensions (2006, background): “While some authors have obtained evidence of such a bimodality (Cordes & Chernoff 1998; Fryer et al. 1998; Arzoumanian et al. 2002; Brisken et al. 2003), others have found Appendices A–”
A Deep Chandra Survey of the Globular Cluster 47 Tucanae: Catalog of Point Sources (2005, unknown): “This estimate significantly alleviates the long-standing problem of neutron star retention in globular clusters (Pfahl et al. 2002a), especially when combined with our current understanding of neutron star kick distributions (Arzoumanian et al. 2002; Pfahl et al. 2002b).”
Getting Its Kicks: A VLBA Parallax for the Hyperfast Pulsar B1508+55 (2005, background): “As the pulsar population velocity distribution has been elucidated (see, e.g., Arzoumanian et al. 2002; Hobbs et al. 2005), binary disruption and the electromagnetic rocket effect have required more extreme assumptions to remain viable, and natal kicks have emerged as the most plausible mechanism…”