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arXiv · astro-ph/9712325

Discovery of >350 GeV Gamma Rays from the BL Lacertae Object 1ES 2344+514

M. Catanese·C. W. Akerlof·H. M. Badran·S. D. Biller·I. H. Bond·P. J. Boyle·S. M. Bradbury·J. H. Buckley·A. M. Burdett·J. Bussons Gordo·D. A. Carter-Lewis·M. F. Cawley·V. Connaughton·D. J. Fegan·J. P. Finley·J. A. Gaidos·T. Hall·A. M. Hillas·F. Krennrich·R. C. Lamb·R. W. Lessard·C. Masterson·J. E. McEnery·G. Mohanty·J. Quinn·A. J. Rodgers·H. J. Rose·F. W. Samuelson·M. S. Schubnell·G. H. Sembroski·R. Srinivasan·T. C. Weekes·C. W. Wilson·J. Zweerink
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Abstract

We present the discovery of >350 GeV gamma-ray emission from the BL Lacertae object 1ES 2344+514 with the Whipple Observatory 10m gamma-ray telescope. This is the third BL Lac object detected at gamma-ray energies above 300 Gev, the other two being Markarian 421 (Mrk 421) and Mrk501. These three active galactic nuclei are all X-ray selected and have the lowest known redshifts of any BL Lac objects currently identified. The evidence for emission derives primarily from an apparent flare on December 20, 1995 when a 6 sigma excess was detected with a flux approximately 63% of the very high energy gamma-ray emission from the Crab Nebula, the standard candle for TeV gamma-ray sources. Excluding the flare, observations between October 1995 and January 1996 yield a 4 sigma detection corresponding to 11% of the VHE Crab Nebula flux. Observations spanning September 1996 to January 1997 failed to yield a significant detection of a steady flux or any flaring. For this period, the 99.9% confidence level upper limit is <8% of the Crab Nebula. The low baseline emission level and variations in nightly and yearly flux of 1ES 22344+514 are the same as the VHE emission characteristics of Mrk 421 and Mrk 501

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M. Catanese, C. W. Akerlof, H. M. Badran, S. D. Biller, I. H. Bond, P. J. Boyle, S. M. Bradbury, J. H. Buckley, A. M. Burdett, J. Bussons Gordo, D. A. Carter-Lewis, M. F. Cawley, V. Connaughton, D. J. Fegan, J. P. Finley, J. A. Gaidos, T. Hall, A. M. Hillas, F. Krennrich, R. C. Lamb, R. W. Lessard, C. Masterson, J. E. McEnery, G. Mohanty, J. Quinn, A. J. Rodgers, H. J. Rose, F. W. Samuelson, M. S. Schubnell, G. H. Sembroski, R. Srinivasan, T. C. Weekes, C. W. Wilson, J. Zweerink. 1997-12-24. Discovery of >350 GeV Gamma Rays from the BL Lacertae Object 1ES 2344+514. https://doi.org/10.1086/305857

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