Observations of the gamma-ray flux from the galaxy Mk 501

We present two-year-long observations of the flux of very-high-energy (simi lar to 10(12) eV) gamma rays from the active galactic nucleus Mk 501 perfor med with a Cherenkov detector at the Crimean Astrophysical Observatory. A g amma-ray flux from the object was shown to exist at confidence levels of 11 and 7 standard deviations for 1997 and 1998, respectively. The flux varied over a wide range. The mean flux at energies >10(12) eV, as inferred from the 1997 and 1998 data, is (5.0 +/- 0.6) x 10(-11) and (3.7 +/- 0.6) x 10(- 11) cm(-2) s(-1), respectively. The errors are the sum of statistical obser vational and modeling errors. The mean power released in the form of gamma rays is similar to 2 x 10(43) erg s(-1) sr(-1). (C) 2000 MAIK "Nauka/Interp eriodica ".