Very high-energy observations of the two high-frequency peaked BL Lac objects 1ES 1218+304 and H 1426+428


We present results of very-high-energy gamma-ray observations (Eγ > 160 GeV) of two high-frequency-peaked BL Lac (HBL) objects, 1ES 1218 + 304 and H 1426 + 428, with the Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE). Both sources are very-high-energy gamma-ray emitters above 100 GeV, detected using ground-based Cherenkov telescopes. STACEE observations of 1ES 1218 + 304 and H 1426 + 428 did not produce detections; we present 99% CL flux upper limits for both sources, assuming spectral indices measured mostly at higher energies.

In Astroparticle Physics