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 (E(0) = 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 Phi(E > 230 TeV) < 2 x 10(-14) cm(-2) s(-1), Phi(E > 90 TeV) < 4.1 x 10(-14) cm(-2) s(-1) and Phi(E > 25 TeV) < 1.9 x 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 approximate to 10(-5)).

Results On Candidate Uhe Gamma-ray Sources By the Eas-top Array (1989-1993) / M., Aglietta; B., Alessandro; P., Antonioli; F., Arneodo; L., Bergamasco; A. C., Fauth; C., Castagnoli; A., Castellina; A., Chiavassa; G., Cini; D'ETTORRE PIAZZOLI, Benedetto; G., Disciascio; W., Fulgione; P., Galeotti; P. L., Ghia; Iacovacci, Michele; G., Mannocchi; C., Morello; G., Navarra; L., Riccati; O., Saavedra; G. C., Trinchero; P., Vallania; S., Vernetto. - In: ASTROPARTICLE PHYSICS. - ISSN 0927-6505. - STAMPA. - 3:(1995), pp. 1-15. [10.1016/0927-6505(94)00026-Y]

Results On Candidate Uhe Gamma-ray Sources By the Eas-top Array (1989-1993)

D'ETTORRE PIAZZOLI, BENEDETTO;IACOVACCI, MICHELE;
1995

Abstract

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 (E(0) = 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 Phi(E > 230 TeV) < 2 x 10(-14) cm(-2) s(-1), Phi(E > 90 TeV) < 4.1 x 10(-14) cm(-2) s(-1) and Phi(E > 25 TeV) < 1.9 x 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 approximate to 10(-5)).
1995
Results On Candidate Uhe Gamma-ray Sources By the Eas-top Array (1989-1993) / M., Aglietta; B., Alessandro; P., Antonioli; F., Arneodo; L., Bergamasco; A. C., Fauth; C., Castagnoli; A., Castellina; A., Chiavassa; G., Cini; D'ETTORRE PIAZZOLI, Benedetto; G., Disciascio; W., Fulgione; P., Galeotti; P. L., Ghia; Iacovacci, Michele; G., Mannocchi; C., Morello; G., Navarra; L., Riccati; O., Saavedra; G. C., Trinchero; P., Vallania; S., Vernetto. - In: ASTROPARTICLE PHYSICS. - ISSN 0927-6505. - STAMPA. - 3:(1995), pp. 1-15. [10.1016/0927-6505(94)00026-Y]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11588/468712
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