| Popis: |
We report on the results of a search for point sources of ultrahigh energy γ radiation in data collected in 1988, 1990, and 1991 by the South Pole Air Shower Experiment. Nine predefined point sources were investigated: the x-ray binaries SMC X-1, LMC X-4, Cen X-3, Vela X-1, 4U1626-67, 4U1145-61, the supernova 1987A, the globular cluster 47 Tucanae, and the unconfirmed source BL-1. No conclusive evidence was found for dc emission from any of the nine candidates. An all sky search for a time-averaged signal was performed, but no significant excess was found. We find a 95% C.L. flux limit of 2.0×10 −13 cm −1 above 50 TeV for all sources, with the exception of Vela X-1 where we have set the limit at 0.6×10 −13 cm −2 s −1 above 200 TeV |
