Search for Bursts of Gamma-Ray Emission from the Crab Pulsar in the Cos-B Data by Adaptive Cluster Analysis
The photon arrival times detected by COS-B around the direction of the Crab pulsar have been analyzed by an adaptive cluster method in order to search for short bursts of gamma-ray emission from the source. As a result, two clusters of 3 and 6 photon arrival times within 264 s and 1813s respectively were found with the corresponding residual phases having close correlation with the peaks of the Crab pulsed emission. The comparison with a similar analysis performed by using photon arrival times not correlated with the Crab direction shows that the events have chance occurrence probabilities of about 10-3 and therefore may be consistent with (rare) random fluctuations of the background. Finally, 3 σ upper limits on the existence of bursts of emission from the Crab are given.
KeywordsResidual Phase Crab Pulsar Chance Occurrence Phase Histogram Pulse Flux
Unable to display preview. Download preview PDF.
- De Jager O.C.; PhD thesis, Univ. of Potchefstroom, 1986Google Scholar
- Fry W.F. ; private communicationGoogle Scholar
- Scarsi L., Bennett K., Bignami G.F., Buccheri R., Hermsen W., Koch L., Mayer-Hasselwander H.A., Paul J.A., Pfeffermann E., Stiglitz R., Swanenburg B.N., Taylor B.G., Wills R.D. ; Proc. of the 12th ESLAB Symp., ESA SP-124, p.3, 1977Google Scholar