2 resultados para Virgo-A radiosorgenti Radioastronomia Getto

em Universidad de Alicante


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Una de las aves del solar hispano más antiguas y más desconocidas es la grulla damisela (Anthropoides virgo). Extinguida de la península ibérica desde la década de los años veinte del siglo pasado, este ave ha recibido diversos vernáculos, desde el más primitivo y genuino de origen arábigo “çaida” (escrito, a veces, como caida, çayda, zaida, zayda, etc.), hasta otros más recientes como “señorita”, “garza de Mallorca”, “grulla de Numidia”, “grulla mora”, “grulla moruna”, o “rugidera”. Nos proponemos pergeñar una somera evolución de aquel olvidado ornitónimo, tan prístino y elegante, recuperando textos literarios e imágenes de interés. Al mismo tiempo, se intenta constatar la presencia de la grulla damisela como ave nativa española.

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We find that the formation of MWC 656 (the first Be binary containing a black hole) involves a common envelope phase and a supernova explosion. This result supports the idea that a rapidly rotating Be star can emerge out of a common envelope phase, which is very intriguing because this evolutionary stage is thought to be too fast to lead to significant accretion and spin up of the B star. We predict ∼10–100 of B-BH binaries to currently reside in the Galactic disc, among which around 1/3 contain a Be star, but there is only a small chance to observe a system with parameters resembling MWC 656. If MWC 656 is representative of intrinsic Galactic Be-BH binary population, it may indicate that standard evolutionary theory needs to be revised. This would pose another evolutionary problem in understanding black hole (BH) binaries, with BH X-ray novae formation issue being the prime example. Future evolution of MWC 656 with an ∼5 M⊙ BH and with an ∼13 M⊙ main-sequence companion on an ∼60 d orbit may lead to the formation of a coalescing BH–NS (neutron star) system. The estimated Advanced LIGO/Virgo detection rate of such systems is up to ∼0.2 yr−1. This empirical estimate is a lower limit as it is obtained with only one particular evolutionary scenario, the MWC 656 binary. This is only a third such estimate available (after Cyg X-1 and Cyg X-3), and it lends additional support to the existence of so far undetected BH–NS binaries.