TY - JOUR
T1 - Results on candidate UHE gamma-ray sources by the EAS-TOP array (1989-1993)
AU - Aglietta, M.
AU - Alessandro, B.
AU - Antonioli, P.
AU - Arneodo, F.
AU - Bergamasco, L.
AU - Campos Fauth, A.
AU - Castagnoli, C.
AU - Castellina, A.
AU - Chiavassa, A.
AU - Cini, G.
AU - D'Ettorre Piazzoli, B.
AU - Di Sciascio, G.
AU - Fulgione, W.
AU - Galeotti, P.
AU - Ghia, P. L.
AU - Iacovacci, M.
AU - Mannocchi, G.
AU - Morello, C.
AU - Navarra, G.
AU - Riccati, L.
AU - Saavedra, O.
AU - Trinchero, G. C.
AU - Vallania, P.
AU - Vernetto, S.
PY - 1995/1
Y1 - 1995/1
N2 - A search for UHE gamma-rays from 13 candidate point sources observable in the northern hemisphere (the Crab Nebula and Pulsar, Cygnus X-3, Hercules X-1, Geminga and others) has been performed by the EAS-TOP array during four years of operation since January 1989 to December 1993, at different energy thresholds (E0 = 30-300 TeV). DC, periodic and sporadic emissions have been studied, and no evidence for significant excesses has been found from any of these searches. The derived 90% c.l. upper limits to the d.c. flux, for a source culminating at the zenith such as Cygnus X-3, are Φ(E > 230 TeV) < 2 × 10-14 cm-2 s-1, Φ(E > 90 TeV) < 4.1 × 10-14 cm-2 s-1 and Φ(E > 25 TeV) < 1.9 × 10-13 cm-2 s-1. The excess from the Crab Nebula of February 23, 1989, as reported by the EAS-TOP, Baksan and KGF arrays, remains the only sporadic excess detected with statistically significant confidence level (probability of background imitation ≈ 10-5).
AB - A search for UHE gamma-rays from 13 candidate point sources observable in the northern hemisphere (the Crab Nebula and Pulsar, Cygnus X-3, Hercules X-1, Geminga and others) has been performed by the EAS-TOP array during four years of operation since January 1989 to December 1993, at different energy thresholds (E0 = 30-300 TeV). DC, periodic and sporadic emissions have been studied, and no evidence for significant excesses has been found from any of these searches. The derived 90% c.l. upper limits to the d.c. flux, for a source culminating at the zenith such as Cygnus X-3, are Φ(E > 230 TeV) < 2 × 10-14 cm-2 s-1, Φ(E > 90 TeV) < 4.1 × 10-14 cm-2 s-1 and Φ(E > 25 TeV) < 1.9 × 10-13 cm-2 s-1. The excess from the Crab Nebula of February 23, 1989, as reported by the EAS-TOP, Baksan and KGF arrays, remains the only sporadic excess detected with statistically significant confidence level (probability of background imitation ≈ 10-5).
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U2 - 10.1016/0927-6505(94)00026-Y
DO - 10.1016/0927-6505(94)00026-Y
M3 - Article
AN - SCOPUS:0002330242
SN - 0927-6505
VL - 3
SP - 1
EP - 15
JO - Astroparticle Physics
JF - Astroparticle Physics
IS - 1
ER -