Galactic populations of radio and gamma-ray pulsars in the polar cap model

Peter L. Gonthier, Michelle S. Ouellette, Joel Berrier, Shawn O'Brien, Alice K. Harding

Research output: Contribution to journalArticle

61 Citations (Scopus)

Abstract

We simulate the characteristics of the Galactic population of radio and γ-ray pulsars using Monte Carlo techniques. At birth, neutron stars are spatially distributed in the Galactic disk, with supernova-kick velocities, and randomly dispersed in age back to 109 yr. They are evolved in the Galactic gravitational potential to the present time. From a radio luminosity model, the radio flux is filtered through a selected set of radio-survey parameters. γ-ray luminosities are assigned using the features of recent polar cap acceleration models invoking space-charge-limited flow, and a pulsar death valley further attenuates the population of radio-loud pulsars. Assuming a simple emission geometry with aligned radio and γ-ray beams of 1 sr solid angle, our model predicts that EGRET should have seen seven radio-loud and one radio-quiet γ-ray pulsars. With much improved sensitivity, GLAST, on the other hand, is expected to observe 76 radio-loud and 74 radio-quiet γ-ray pulsars, of which seven would be identified as pulsed sources. We also explore the effect of magnetic field decay on the characteristics of the radio and γ-ray pulsar populations. Including magnetic field decay on a timescale of 5 Myr improves agreement with the radio pulsar population and increases the predicted number of GLAST-detected pulsars to 90 radio-loud and 101 radio-quiet (nine pulsed) γ-ray pulsars. The lower flux threshold allows GLAST to detect γ-ray pulsars at larger distances than those observed by the radio surveys used in this study.

Original languageEnglish (US)
Pages (from-to)482-499
Number of pages18
JournalAstrophysical Journal
Volume565
Issue number1 I
DOIs
StatePublished - Jan 20 2002

Fingerprint

polar caps
pulsars
gamma rays
radio
rays
Fermi Gamma-ray Space Telescope
Death Valley (CA)
luminosity
decay
magnetic fields
gravitational fields
neutron stars
magnetic field
supernovae
space charge
thresholds

Keywords

  • Gamma rays: theory
  • Magnetic fields
  • Pulsars: general
  • Radiation mechanisms: nonthermal
  • Stars: neutron

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Gonthier, P. L., Ouellette, M. S., Berrier, J., O'Brien, S., & Harding, A. K. (2002). Galactic populations of radio and gamma-ray pulsars in the polar cap model. Astrophysical Journal, 565(1 I), 482-499. https://doi.org/10.1086/324535

Galactic populations of radio and gamma-ray pulsars in the polar cap model. / Gonthier, Peter L.; Ouellette, Michelle S.; Berrier, Joel; O'Brien, Shawn; Harding, Alice K.

In: Astrophysical Journal, Vol. 565, No. 1 I, 20.01.2002, p. 482-499.

Research output: Contribution to journalArticle

Gonthier, PL, Ouellette, MS, Berrier, J, O'Brien, S & Harding, AK 2002, 'Galactic populations of radio and gamma-ray pulsars in the polar cap model', Astrophysical Journal, vol. 565, no. 1 I, pp. 482-499. https://doi.org/10.1086/324535
Gonthier, Peter L. ; Ouellette, Michelle S. ; Berrier, Joel ; O'Brien, Shawn ; Harding, Alice K. / Galactic populations of radio and gamma-ray pulsars in the polar cap model. In: Astrophysical Journal. 2002 ; Vol. 565, No. 1 I. pp. 482-499.
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