Recent observations of γ-rays above 1.5 TeV from Mkn 501 with the HEGRA 5 m2 air Čerenkov telescope

Since February 1997 the BL Lac object Mkn 501 is in a “high state” of γ-ray emission. The HEGRA collaboration has studied Mkn 501 with their air Cerenkov telescopes on La Palma. Here we report on observations with the 5 m2 telescope (threshold≈1.5 TeV) operated in a stand alone mode. We observed a rapidly varying flux between 0.5 to 6 times of that from the Crab Nebula. On average a Mkn 501 flux of (2+1.3−0.5)×10−11 cm−2 s−1 has been determined. The spectrum extends at least up to 10 TeV with an integral power law coefficient of 1.8±0.2 and seems to be steeper than in 1996.