On the difference between gamma-ray-detected and non-gamma-ray-detected pulsars

Abstract

We compare radio profile widths of young, energetic gamma-ray-detected and non-gamma-ray-detected pulsars. We find that the latter typically have wider radio profiles, with the boundary between the two samples exhibiting a dependence on the rate of rotational energy loss. We also find that within the sample of gamma-ray-detected pulsars, radio profile width is correlated with both the separation of the main gamma-ray peaks and the presence of narrow gamma-ray components. These findings lead us to propose that these pulsars form a single population where the main factors determining gamma ray detectability are the rate of rotational energy loss and the proximity of the line of sight to the rotation axis. The expected magnetic inclination angle distribution will be different for radio pulsars with and without detectable gamma rays, naturally leading to the observed differences. Our results also suggest that the geometry of existing radio and outer-magnetosphere gamma-ray emission models are at least qualitatively realistic, implying that information about the viewing geometry can be extracted from profile properties of pulsars.

10 pages, 3 figures, 1 table, accepted for publication in MNRAS

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Cited by in corpus (9)

• The Third Fermi Large Area Telescope Catalog of Gamma-ray Pulsars
• The Thousand-Pulsar-Array programme on MeerKAT: -- VI. Pulse widths of a large and diverse sample of radio pulsars
• Extreme Scattering Events Towards Two Young Pulsars
• An image-based search for pulsars among Fermi unassociated LAT sources
• The Galactic population and properties of young, highly-energetic pulsars
• A polarization census of bright pulsars using the Ultra-Wideband Receiver on the Parkes radio telescope
• The Green Bank North Celestial Cap Survey. VII. 12 New Pulsar Timing Solutions
• Constraining the geometry of PSR J0855-4644: A nearby Pulsar Wind Nebula with Double Torus/Jet Morphology
• Frequency evolution of pulsar emission: Further evidence for fan beam model