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

doi:10.1086/305857

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arXiv · astro-ph/9712325

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

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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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