A survey of 56 midlatitude egret error boxes for radio pulsars

Fronefield Crawford, Mallory Roberts, Jason W T Hessels, Scott M. Ransom, Margaret Livingstone, Cindy R. Tam, Victoria M. Kaspi

Research output: Contribution to journalArticle

Abstract

We have conducted a radio pulsar survey of 56 unidentified γ-ray sources from the third EGRET catalog that are at intermediate Galactic latitudes (5° < |b| < 73°). For each source, four interleaved 35 minute pointings were made with the 13 beam, 1400 MHz multibeam receiver on the Parkes 64 m radio telescope. This covered the 95% error box of each source at a limiting sensitivity of ∼0.2 mJy to pulsed radio emission for periods P ≳ 10 ms and dispersion measures ≲ 50 pc cm-3. Roughly half of the unidentified γ-ray sources at |b| > 5° with no proposed active galactic nucleus counterpart were covered in this survey. We detected nine isolated pulsars and four recycled binary pulsars, with three from each class being new discoveries. Timing observations suggest that only one of the pulsars has a spin-down luminosity that is even marginally consistent with the inferred luminosity of its coincident EGRET source. Our results suggest that population models, which include the Gould Belt as a component, overestimate the number of isolated pulsars among the midlatitude Galactic γ-ray sources, and that it is unlikely that Gould Belt pulsars make up the majority of these sources. However, the possibility of steep pulsar radio spectra and the confusion of terrestrial radio interference with long-period pulsars (P ≳ 200 ms) having very low dispersion measures (≲ 10 pc cm-3, expected for sources at a distance of less than about 1 kpc) prevent us from strongly ruling out this hypothesis. Our results also do not support the hypothesis that millisecond pulsars make up the majority of these sources. Nonpulsar source classes should therefore be further investigated as possible counterparts to the unidentified EGRET sources at intermediate Galactic latitudes.

Original languageEnglish (US)
Pages (from-to)1499-1507
Number of pages9
JournalAstrophysical Journal
Volume652
Issue number2 I
DOIs
StatePublished - Dec 1 2006

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temperate regions
pulsars
boxes
radio
rays
luminosity
radio frequency interference
radio spectra
confusion
active galactic nuclei
catalogs
time measurement

Keywords

  • Gamma rays: observations
  • Pulsars: general

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Space and Planetary Science

Cite this

Crawford, F., Roberts, M., Hessels, J. W. T., Ransom, S. M., Livingstone, M., Tam, C. R., & Kaspi, V. M. (2006). A survey of 56 midlatitude egret error boxes for radio pulsars. Astrophysical Journal, 652(2 I), 1499-1507. https://doi.org/10.1086/508403

A survey of 56 midlatitude egret error boxes for radio pulsars. / Crawford, Fronefield; Roberts, Mallory; Hessels, Jason W T; Ransom, Scott M.; Livingstone, Margaret; Tam, Cindy R.; Kaspi, Victoria M.

In: Astrophysical Journal, Vol. 652, No. 2 I, 01.12.2006, p. 1499-1507.

Research output: Contribution to journalArticle

Crawford, F, Roberts, M, Hessels, JWT, Ransom, SM, Livingstone, M, Tam, CR & Kaspi, VM 2006, 'A survey of 56 midlatitude egret error boxes for radio pulsars', Astrophysical Journal, vol. 652, no. 2 I, pp. 1499-1507. https://doi.org/10.1086/508403
Crawford F, Roberts M, Hessels JWT, Ransom SM, Livingstone M, Tam CR et al. A survey of 56 midlatitude egret error boxes for radio pulsars. Astrophysical Journal. 2006 Dec 1;652(2 I):1499-1507. https://doi.org/10.1086/508403
Crawford, Fronefield ; Roberts, Mallory ; Hessels, Jason W T ; Ransom, Scott M. ; Livingstone, Margaret ; Tam, Cindy R. ; Kaspi, Victoria M. / A survey of 56 midlatitude egret error boxes for radio pulsars. In: Astrophysical Journal. 2006 ; Vol. 652, No. 2 I. pp. 1499-1507.
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