Observations on TeV gamma rays from Geminga and PSR 0950+08

Abstract

The Geminga (2 CG 195+04) which exhibits a periodicity with a period of 59 to 60 s in its emission of X-rays, GeV gamma rays and TeV gamma rays was studied. During the winter of 1984 to 1985, this object was observed to see if it emits TeV gamma rays with a periodicity approx 60 s. The observations were carried out at two different sites separated by 11 Km with the Ooty Atmospheric Cerenkov Array split into two parts. Data were collected during clear moonless nights for a total duration of 15.3 hours spread over 2 months. Since the first time derivative of period is believed to be large and uncertain. The total data are subdivided into segments of duration not more than 3 days each to steer clear of the effects of P in the phase analysis. If TeV gamma ray signals are seen in each of these segments, it is possible to derive P from observed data