GeV Gamma-ray Pulsar Detection

David Stanley Smith (1) , David J. Thompson

1 CENBG - Centre d'Etudes Nucléaires de Bordeaux Gradignan

Pulsar observations at high energies, i.e., beyond radio frequencies, shed a different light on the mechanisms at work near rotating neutron stars. This article assumes that the reader is already convinced that substantially increasing the known sample of gamma ray pulsars beyond the ̃8 seen with the instruments on the Compton Gamma Ray Observatory (CGRO) is a worthy goal [36, 63], to focus on how this goal is being pursued. “Detection” comes in degrees. Simply counting the number of gamma ray excesses positionally coincident with known neutron stars is useful for population studies, even if source confusion will compromise some associations. Pulsed detection removes identification ambiguities while bringing precious information about beam geometry via light curve shapes: the EGRET pulsars mainly have two peaks, with the leading peak slightly offset compared to the single radio peak, and we would like to know how general this rule is [64]. Accurate determination of the cutoff energy, and, hopefully, the shape of the cut-off, is the next step. And finally, with enough photon statistics the spectral shape can be broken down by phase-interval. Having these observables on a large sample of pulsars should allow major steps forward in describing where and how high energy particles are accelerated.

Domaines: Phénomènes cosmiques de haute energie [astro-ph.HE]; Phénomènes cosmiques de haute energie [astro-ph.HE]

David Stanley Smith, David J. Thompson. GeV Gamma-ray Pulsar Detection. 363rd Heraeus "Neutron Stars and Pulsars about 40 Years after their Discovery", May 2006, Bad Honnef, Germany. pp.621-649. ⟨in2p3-00411125⟩