Observations of Mkn 421 using Pachmarhi Array of Čerenkov Telescopes

Pachmarhi Array of Čerenkov Telescopes (PACT), based on wavefront sampling technique, has been used for detecting TeV gamma rays from galactic and extra-galactic γ-ray sources. The Blazar, Mkn 421 was one such extragalactic source observed during the winter nights of 2000 and 2001. We have carried out a preliminary analysis of the data taken during the nights of January, 2000 and 2001. Results show a significant gamma ray signal from this source during both these periods above a threshold energy of 900 GeV. The source was contemporaneously observed by CAT imaging telescope during the first episode of January 2000 while HEGRA CT1 was observing the source during the second episode. Both these observations have detected variable γ-ray emission this source and they reported that it was flaring during both these periods. The light curve in the TeV gamma ray range derived from the first PACT observations during both these episodes is in agreement with that reported by other experiments. The analysis procedure and the preliminary results will be presented and discussed.