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

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

We present X-ray and multi-frequency radio observations of the central radio sources in several X-ray cavity systems. We show that targeted radio observations are key to determining if the lobes are being actively fed by the central AGN. Low frequency observations provide a unique way to study both the lifecycle of the central radio source as well as its energy input into the ICM over several o...

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 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.