| Autor: |
S. M. Rayner, J. E. Dickinson, P. M. Chadwick, S.M. Bradbury, E. W. Lincoln, T. J. L. McComb, K. J. Orford, K. E. Turver, P. J. Edwards, C. C. G. Bowden, Nigel Dipper |
| Rok vydání: |
1992 |
| Předmět: |
|
| Zdroj: |
Astroparticle Physics. 1:47-59 |
| ISSN: |
0927-6505 |
| DOI: |
10.1016/0927-6505(92)90008-n |
| Popis: |
We report here the results of VHE γ-ray observations made during 1990 and 1991 using the Durham University Mark III and IV VHE γ-ray telescopes at Narrabri, N.S.W., Australia. There are 4 separate datasets, each obtained from observations over typically 10 days during a lunar dark period. The dataset from October 1990 exhibits periodicity at a chance probability of 1 × 10 -4 , and a similar effect is noted in the dataset from August 1991 at 1.6 × 10 −2 . In both cases, most of the power is in the second harmonic; the period is constant over at least 10 days and similar to that seen at optical wavelengths. No significant signal was detected in the September 1991 and October 1991 datasets. In addition, a strong and highly significant outburst lasting about 1 minute on 13 October 1990 and detected by two independent telescopes is reported. This outburst shows the 33 s periodic pulse structure and the pulses are in phase with those observed during the strongest sustained periodic signal in our data, from an observation lasting 3 h and taken 48 h previously. A second, weaker burst was also observed during August 1991. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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