Evidence for TeV gamma ray emission from TeV J2032+4130 in Whipple archival data

¹ Department of Physics, National University of Ireland, Galway, Ireland e-mail: mark.lang@nuigalway.ie
² Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA
³ Department of Experimental Physics, University College, Belfield, Dublin 4, Ireland
⁴ Fred Lawrence Whipple Observatory, Harvard-Smithsonian CfA, Amado, AZ 85645, USA
⁵ Department of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT, UK
⁶ Space Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125, USA
⁷ Physique Corpusculaire et Cosmologie, Collège de France, 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France
⁸ Department of Applied Physics and Instrumentation, Cork Institute of Technology, Bishopstown, Cork, Ireland

Received: 5 April 2004
Accepted: 12 May 2004

Abstract

A reanalysis of data taken on the Cygnus region in 1989–90 using the Whipple Observatory atmospheric Cherenkov imaging telescope confirms the existence of the TeV J2032+4130 source reported by the Crimean Astrophysical Observatory and published by the HEGRA Collaboration. The significance at the a priori HEGRA position is 3.3σ. The peak signal was found at RA = 20h32m, Dec = +41°33'. This is 0.6° north of Cygnus X-3 which was the original target of the observations. The flux level (12% of the level of the Crab Nebula) is intermediate between the two later observations and suggests that the TeV source is variable.