Two multifrequency observations of 3C 371

MAGIC observations and multifrequency properties of the flat spectrum radio quasar 3C 279 in 2011

Aims. We study the multifrequency emission and spectral properties of the quasar 3C 279 aimed at identifying the radiation processes taking place in the source. Methods. We observed 3C 279 in very-high-energy (VHE, E > 100 GeV) γ-rays, with the MAGIC telescopes during 2011, for the first time in stereoscopic mode. We combined these measurements with observations at other energy bands: in high-e...

BeppoSAX observations of 3C 273

3c 129 : the Gmrt Observations

We present radio maps of the head-tail radio galaxy, 3C 129 at 240 and 610 MHz using the Giant Metrewave Radio Telescope. We have studied in detail the morphology of the source and the distribution of spectral index over the object. We find large-scale spectral steepening along the jet away from the core. Using synchrotron spectral ageing theory, we infer the age (time since particle accelerati...

Clusters of Galaxies: Multifrequency Observations versus Theories

Clusters of galaxies are large gravitationally bound systems which consist of several observable components: hundreds of galaxies, hot gas between the galaxies and sometimes relativistic particles. These components are emitting in different wavelengths from radio to X-rays. We show that the combination of observations at different frequencies and also theoretical models is giving now a comprehe...

VLA multifrequency observations of RS CVn binaries

We present multiepoch Very Large Array (VLA) observations at 1.4 GHz, 4.9 GHz, 8.5 GHz and 14.9 GHz for a sample of eight RS CVn binary systems. Circular polarization measurements of these systems are also reported. Most of the fluxes observed are consistent with incoherent emission from mildly relativistic electrons. Several systems show an increase of the degree of circular polarization with ...