A Search for Ultra–High‐Energy Gamma‐Ray Emission from the Crab Nebula and Pulsar
| Autor: | M. A. K. Glasmacher, D. Sinclair, David Kieda, R. A. Ong, M. A. Catanese, D. Nitz, K. Gibbs, J. F. Fowler, K. D. Green, John Matthews, Corbin Covault, J. W. Cronin, Lucy Fortson, J. C. van der Velde, L. J. Rosenberg, Brian Fick, B. J. Newport, M. C. Chantell, A. Borione |
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| Rok vydání: | 1997 |
| Předmět: | |
| Zdroj: | The Astrophysical Journal. 481:313-326 |
| ISSN: | 1538-4357 0004-637X |
| Popis: | We have examined 2.4 × 109 events recorded by the Chicago Air Shower Array-Michigan Muon Array (CASA-MIA) experiment for evidence of ultra-high-energy (100 TeV) neutral particle and gamma-ray emissions from the Crab Nebula and Pulsar between 1990 March 4 and 1995 October 9. No such emissions have been detected. Over this interval, the 90% confidence level integral flux limits for continuous emission above 141 TeV are 2.08 × 10-14 cm-2 s-1 for any neutral particle (which can produce a detectable air shower) and 9.21 × 10-15 cm-2 s-1 for gamma rays. There is no evidence of transient emission on timescales of 1 day or longer. The 90% confidence level integral flux limit for emission on a single day is conservatively estimated to be 4.40 × 10-12 cm-2 s-1 for any neutral particle and 5.09 × 10-12 cm-2 s-1 for gamma rays. There is no evidence for emission from the pulsar at the radio period on intervals of 1 day or longer. The 2 σ (97.7% confidence) limit on the pulsed flux on the most significant day is 3.29 × 10-12 cm-2 s-1 for any neutral particle with mass less than 21 MeV, and 8.31 × 10-12 cm-2 s-1 for gamma rays. For an interval of 162 sidereal days beginning 1992 March 1, the pulsed flux limit was 2.39 × 10-13 cm-2 s-1 for any neutral particle with mass less than 21 MeV, again above 141 TeV. |
| Databáze: | OpenAIRE |
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