ar X iv : a st ro - p h / 01 07 46 7 v 1 2 4 Ju l 2 00 1 The Spectacular BHR 71 Outflow

ar X iv : a st ro - p h / 04 07 23 2 v 1 1 2 Ju l 2 00 4 B The Saas Fee Lectures on Strong Gravitational Lensing

ar X iv : a st ro - p h / 01 11 13 6 v 1 7 N ov 2 00 1 1 Active Optics in Modern , Large Optical Telescopes

ar X iv : a st ro - p h / 04 08 01 0 v 1 3 1 Ju l 2 00 4 On the nature of the unidentified X - ray / γ - ray sources

We present a multiwavelength study of the environment of the unidentified X-ray/γ-ray sources IGR J18027−1455 and IGR J21247+5058, recently discovered by the IBIS/ISGRI instrument, onboard the INTEGRAL satellite. The main properties of the sources found inside their position error circles, give us clues about the nature of these high-energy sources.

ar X iv : a st ro - p h / 06 07 53 9 v 1 2 4 Ju l 2 00 6 CLUSTERS AND THE COSMIC WEB : Identifying the location of filaments

ar X iv : a st ro - p h / 01 03 44 4 v 1 2 7 M ar 2 00 1 From Centimeter to Millimeter Wavelengths : A High Angular Resolution Study of 3 C 273

We monitored 3C 273 with VLBI at 15–86 GHz since 1990. We discuss component trajectories, opacity effects, a rotating jet, and outburst-ejection relations from Gamma-ray to radio bands.