出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We analyzed radio (Ryle Telescope) and X-ray (RXTE, INTEGRAL) observations of GRS 1915+105, between May 1995 and June 2006, focusing on the times characterized by radio flares and cycles of hard dips – soft spikes in the X-ray lightcurve. Assuming these flares to be discrete ejections, we fitted a total of 687 radio flares with a standard model of a plasmon. We found that the distribution of width is t0 = 1160 s with an rms deviation of 360 s, while that of the amplitude is Smax = 59 mJy with an rms deviation of 28 mJy. The distribution of width is thus rather peaked, while that of the amplitude not. Regarding radio and X-ray links, this study confirms previous observations on smaller datasets, namely that X-ray cycles of hard dips – soft spikes are always followed by radio flares. A strong correlation is found between the length of X-ray “dips" in the X-ray lightcurves, and the amplitude and fluence of the subsequent radio oscillations. A model of an exponential rise of the form L15 GHz(Dt) = Lmax(1−exp(−(Dt−Dtmin)/t ) is in good agreement with the observations, with the maximum fluence Lmax of the order 70 Jy.s, and the characteristic time t of the order 200-500 s. We discuss possible physical interpretations of this correlation, regarding the physical process responsible for the ejection.
