Search For Tev Gamma-Rays From H1426+428 During 2004-2007 With The Tactic Telescope

The BL Lac object H1426+428 (z equivalent to 0.129) is an established source of TeV gamma-rays and detections of these photons from this object also have important implications for estimating the extragalactic background light in addition to the understanding of the particle acceleration and gamma-ray production mechanisms in the AGN jets. We have observed this source for about 244 h in 2004, 2006 and 2007 with the TACTIC gamma-ray telescope located at Mt Abu, India. Detailed analysis of these data do not indicate the presence of any statistically significant TeV gamma-ray signal from the source direction. Accordingly, we have placed an upper limit of <= 1.18 x 10(-12) photons cm(-2) s(-1) on the integrated. gamma-ray flux at 3 sigma significance level.