2026-04-17T03:20:16Zhttps://recercat.cat/oai/request

oai:recercat.cat:2445/1228382025-11-21T05:48:42Zcom_2072_1057col_2072_478823col_2072_478904col_2072_478917

00925njm 22002777a 4500 dc Bordas Coma, Pol author Bosch i Ramon, Valentí author Cañellas, A. author Moldón Vara, Francisco Javier author Munar i Adrover, Pere author Paredes i Poy, Josep Maria author Ribó Gomis, Marc author Zabalza de Torres, Víctor author 2018-06-07T13:43:04Z 2018-06-07T13:43:04Z 2011-07-01 2018-06-07T13:43:05Z 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. Acceleradors de partícules Estels binaris de raigs X Raigs X Particle accelerators X-ray binaries X-rays A search for Very High Energy gamma-ray emission from Sco X-1 with the MAGIC telescopes