Título:
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A search for Very High Energy gamma-ray emission from Sco X-1 with the MAGIC telescopes
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Autor/a:
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Bordas Coma, Pol; Bosch i Ramon, Valentí; Cañellas, A.; Moldón Vara, Francisco Javier; Munar i Adrover, Pere; Paredes i Poy, Josep Maria; Ribó Gomis, Marc; Zabalza de Torres, Víctor
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Otros autores:
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Universitat de Barcelona |
Abstract:
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The acceleration of particles up to GeV or higher energies in microquasars has been the subject of considerable theoretical and observational efforts in the past few years. Sco X-1 is a microquasar from which evidence of highly energetic particles in the jet has been found when it is in the so-called Horizontal Branch (HB), a state when the radio and hard X-ray fluxes are higher and a powerful relativistic jet is present. Here we present the first very high energy gamma-ray observations of Sco X-1 obtained with the MAGIC telescopes. An analysis of the whole dataset does not yield a significant signal, with 95% CL flux upper limits above 300 GeV at the level of 2.4x10^{-12} ph/cm^2/s. Simultaneous RXTE observations were conducted to search for TeV emission during particular X-ray states of the source. A selection of the gamma-ray data obtained during the HB based on the X-ray colors did not yield a signal either, with an upper limit of 3.4x10^{-12} ph/cm^2/s. These upper limits place a constraint on the maximum TeV luminosity to non-thermal X-ray luminosity of L_{VHE}/L_{ntX}<0.02, that can be related to a maximum TeV luminosity to jet power ratio of L_{VHE}/L_{j}<10^{-3}. Our upper limits indicate that the underlying high-energy emission physics in Sco X-1 must be inherently different from that of the hitherto detected gamma-ray binaries. |
Materia(s):
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-Acceleradors de partícules -Estels binaris de raigs X -Raigs X -Particle accelerators -X-ray binaries -X-rays |
Derechos:
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(c) American Astronomical Society, 2011
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Tipo de documento:
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Artículo Artículo - Versión publicada |
Editor:
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Institute of Physics (IOP)
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