Observational evidence for mass ejection during soft X-ray dips in GRS 1915+105

We investigate the connection between tile X-ray and radio properties of th e Galactic microquasar GRS 1915+105, by analyzing the X-ray data observed w ith RXTE, during tile presence of a huge radio flare (similar to 450 mJy). The X-ray lightcurve shows two dips of similar to 100 s duration. Detailed time resolved spectral analysis shows the existence of three spectral compo nents: a multicolor disk-blackbody a Comptonized component, due to hot plas ma and a power-law. We find that the Comptonized component is very weak dur ing the dip. This is further confirmed by the PHA ratio of the raw data and ratio of tile lightcurves in different energy bands. These results, combin ed with the fact that the 0.5-10 Hz QPO disappears during tile dip and that the Comptonized component is responsible for the QPO lead to the conclusio n l;l-lat during the dips the matter emitting; Comptonized spectrum is ejec ted away. This establishes a direct connection between the X-ray and radio properties of tile source.