BATSE observations of the Piccinotti sample of active galactic nuclei

BATSE Earth-occultation data have been used to search for emission in the 20-100 keV band from all sources in the Piccinotti sample, which represents the only complete 2-10 keV survey to date of the extragalactic sky down to a limiting flux of 3.1 x 10(-11) ergs cm(-2) s(-1). Nearly 4 yr of observations have been analyzed to reach a 5 sigma sensitivity level of about 7.8 x 10(-11) ergs cm(-2) s(-1) in the band considered. Of the 36 sources in the sample:, 14 have been detected above the 5 sigma confidence level, while marginal detection (3 less than or equal to sigma less than or equal to 5) can be claimed for 13 sources; for nine objects 2 sigma upper limits are reported. A comparison of BATSE results with data at higher energies is used to estimate the robustness of our data analysis: while the detection level of each source is reliable, the flux measurement maybe overestimated in some sources by as much as 35%, probably because of incomplete data cleaning. Comparison of BATSE fluxes with X-ray fluxes obtained in the 2-10 keV range and averaged over years indicates that a canonical power law of photon index 1.7 gives a good description of the broadband spectra of bright active galactic nuclei (AGNs) and that spectral breaks preferentially occur above 100 keV.