The search for short-term flares in extended VHE Crab Nebula observations with the Whipple 10m telescope
| Autor: | de Bhroithe, Anna O'Faolain, collaboration, VERITAS |
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| Rok vydání: | 2015 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | In 1989, the Whipple 10m telescope achieved the first indisputable detection of a TeV gamma-ray source, the Crab Nebula. Until its decommissioning in 2011, the Whipple telescope took regular measurements of the nebula. With the recent discovery of GeV gamma-ray flaring activity in the Crab Nebula, it is an opportune time to return to the Whipple telescope data set and search its extensive archive for evidence of TeV flares. A data set on the Crab Nebula spanning ten years, 2000 - 2010, is compiled and searched for day-scale flaring activity using a Bayesian-block binning algorithm. No evidence for significant flaring activity is found. Monte Carlo simulations show that low levels of flux increase on short timescales are difficult to detect. Assuming a flare duration of seven days, 99% confidence level upper limits are calculated for the possible frequency of five-fold, two-fold and 1.5-fold flares in the data set. An upper limit of 0.02 flares per year is found for the five-fold flare, and a limit of 0.27 flares per year is placed on the two-fold flare. The detection of the 1.5-fold flare is consistent with the false-positive rate of the method, and so cannot be excluded. Comment: 8 pages, 2 figures, in proceedings of the 34th International Cosmic Ray Conference |
| Databáze: | arXiv |
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