VLBA Observations of GRS 1915+105

VLBA Observations of Blazars

VLBI observations of blazars provide the closest look at compact jets that are thought to be responsible for the variable emission of blazars from radio to γ-ray wavelengths. It appears that flux variability at different wavelengths is connected to changes in jet structure near its base. The changes happen on timescales of weeks or less, which require frequent VLBI monitoring to follow. Current...

Multi - transition VLBA observations of circumstellar SiO

On this paper, we present simultaneous VLBA observations of the J=1–0 and J=2–1 rotational lines in the v=1 and v=2 vibra-tionally excited states of SiO (at λ ∼ 7 and 3 mm). We have mapped these four maser lines in the circumstellar envelopes of three AGB stars: IRC +10011, χ Cyg and TX Cam. We study the relative spatial distribution between these maser lines. In particular, for the two v=1 tra...

0 EVN Observations of GRS 1915 +

X-ray Observations of Grs 1915+105

1. Spectral analysis of simultaneous ROSAT/BATSE data After the discovery of GRS 1915+105 (Castro-Tirado et al. 1992) we obtained pointed ROSAT observations every six months (12 until now). The flux in the ROSAT (0.1–2.4 keV) band is strikingly different from the simultaneous BATSE (25–50 keV) flux which was obtained by integrating the best fit power law (Fig. 1). Motivated by the different int...

Rxte Observations of Grs 1915+105

We report on extensive X-ray observations of the galactic superlu-minal motion source GRS 1915+105 with the RXTE satellite over the last year. More than 130 RXTE pointings have been performed on roughly a weekly basis. GRS 1915+105 displays drastic X-ray intensity variations on a variety of time scales ranging from sub-seconds to days. In general, the intensity changes are accompanied by spectr...