ar X iv : a st ro - p h / 06 12 59 5 v 1 2 0 D ec 2 00 6 Tracing Ghost Cavities with Low Frequency Radio Observations

ar X iv : a st ro - p h / 06 12 53 0 v 1 1 9 D ec 2 00 6 High sensitivity low frequency radio observations of cD galaxies

We present the GMRT 235 MHz images of three radio galaxies and 610 MHz images of two sources belonging to a complete sample of cD galaxies in rich and poor galaxy clusters. The analysis of the spectral properties confirms the presence of aged radio emission in two of the presented sources.

ar X iv : a st ro - p h / 06 12 49 0 v 1 1 8 D ec 2 00 6 Multi - frequency radio observations of BAL quasar 1045 + 352

Multi-frequency 1.7, 5 and 8.4-GHz VLBA observations of a radio-loud broad absorption line (BAL) quasar 1045+352 are presented. It is a young compact steep spectrum (CSS) object and its asymmetric, two-sided morphology on a scale of several hundred parsecs, extending in two different directions, may suggest intermittent activity. The young age and unusual morphology of 1045+352 are arguments in...

ar X iv : a st ro - p h / 06 12 37 8 v 1 1 4 D ec 2 00 6 Magnetic fields , strings and cosmology

ar X iv : a st ro - p h / 06 12 42 6 v 1 1 5 D ec 2 00 6 Heating and Cooling in the Perseus Cluster Core

ar X iv : a st ro - p h / 02 12 56 6 v 1 3 0 D ec 2 00 2 Dark Energy : Is it Q or Λ ?

New observations of Cosmic Microwave Background Anisotropies, Su-pernovae luminosity distances and Galaxy Clustering are sharpening our knowledge about dark energy. Here we present the latest constraints.