A Search for Radio-quiet Gamma-Ray Pulsars
Abstract
Most Galactic point sources of gamma rays remain unidentified. The few (extrasolar) sources that have been identified are all young, rotation-powered pulsars, all but one of which were identified using radio ephemerides. The radio-quiet Geminga pulsar was identified only after pulsations were discovered in a coincident X-ray source. Observational evidence indicates that many of the unidentified Galactic sources are likely to be pulsars, and some theoretical models predict a potentially large population of radio-quiet gamma-ray pulsars. We present a new method for performing sensitive gamma-ray pulsar searches. We used this method to search several of the strongest EGRET sources for pulsations. This was a blind search for new pulsars, covering a frequency and a frequency-derivative phase space large enough to detect Crab-like pulsars as well as lower frequency, high magnetic field ``magnetars.'' No new pulsars were discovered, and we report upper limits constraining the characteristics of any signals contained in the data sets searched.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 2001
- DOI:
- 10.1086/321573
- Bibcode:
- 2001ApJ...556...59C
- Keywords:
-
- Gamma Rays: Observations;
- Stars: Pulsars: General