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Título:
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Detection of very-high energy gamma-ray emission from NGC 1275 by the MAGIC telescopes
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Autores:
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Antoranz Canales, Pedro ;
Barrio Uña, Juan Abel ;
Contreras González, José Luis ;
Fonseca González, Mª Victoria ;
Miranda Pantoja, José Miguel ;
Scapin, Valeria
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Tipo de documento:
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texto impreso
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Editorial:
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EDP Sciences, 2012-03
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Dimensiones:
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application/pdf
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Nota general:
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info:eu-repo/semantics/openAccess
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Idiomas:
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Palabras clave:
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Estado = Publicado
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Materia = Ciencias: Física: Electrónica
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Materia = Ciencias: Física: Electricidad
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Materia = Ciencias: Física: Física nuclear
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Tipo = Artículo
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Resumen:
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We report on the detection of very-high energy (VHE, E > 100 GeV) gamma-ray emission from NGC 1275, the central radio galaxy of the Perseus cluster of galaxies. The source has been detected by the MAGIC telescopes with a statistical significance of 6.6s above 100 GeV in 46 h of stereo observations carried out between August 2010 and February 2011. The measured differential energy spectrum between 70 GeV and 500 GeV can be described by a power law with a steep spectral index of Gamma = -4.1 +/- 0.7(stat) +/- 0.3(syst), and the average flux above 100 GeV is F-gamma = (1.3 +/- 0.2(stat) +/- 0.3(syst)) x 10(-11) cm(-2) s(-1). These results, combined with the power-law spectrum measured in the first two years of observations by the Fermi-LAT above 100 MeV, with a spectral index of Gamma similar or equal to -2.1, strongly suggest the presence of a break or cut-off around tens of GeV in the NGC 1275 spectrum. The light curve of the source above 100 GeV does not show hints of variability on a month time scale. Finally, we report on the nondetection in the present data of the radio galaxy IC 310, previously discovered by the Fermi-LAT and MAGIC. The derived flux upper limit F-gamma(U.L.) (> 300 GeV) = 1.2 x 10(-12) cm(-2) s(-1) is a factor similar to 3 lower than the mean flux measured by MAGIC between October 2009 and February 2010, thus confirming the year time-scale variability of the source at VHE.
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En línea:
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https://eprints.ucm.es/id/eprint/21330/1/MirandaJM08abierto.pdf
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