Related papers: Radio Lobe Dynamics and the Environment of Microqu…

We present the first detailed low frequency radio measurements of the galactic microquasar GRS1915+105 with GMRT. Simultaneous observations were carried out at 610 and 244 MHz. Our data does not show any signature of spectral turn over even…

We analyze ROSAT data for cluster gas surrounding powerful radio galaxies, which is well fitted by a ``beta-model'' gas distribution, after allowing for a compact central source. The cluster thermal pressure at the distance of the radio…

We have obtained multi-colour imaging of a representative, statistically complete sample of low-frequency selected (S_408MHz > 0.95Jy) radio loud quasars at intermediate (0.6 < z < 1.1) redshifts. These sources are found in a variety of…

The jets of GRS 1915+105 carry a considerable energy away from the central source into the ISM. The similarity of the jets of this source and jets in radio galaxies or radio-loud quasars suggests that we should detect large-scale,…

Typical blazars seem to be associated with FR I and FR II radio galaxies and radio-loud quasars. However, what happens at lower powers? Do blazars exist in low-luminosity AGN or do they exist in radio-quiet AGN? A recent detection of…

The large mechanical luminosity of the jets of GRS 1915+105 should give rise to luminous emission regions, similar to those observed in radio galaxies, where the jets interact with the gas surrounding the source. However, no radio…

We present results from two suites of simulations of powerful radio galaxies in poor cluster environments, with a focus on the formation and evolution of the radio lobes. One suite of models uses relativistic hydrodynamics and the other…

We present preliminary results of a study of the low frequency radio continuum emission from the nuclei of Giant Low Surface Brightness (LSB) galaxies. We have mapped the emission and searched for extended features such as radio lobes/jets…

We present 150 MHz, 1.4 GHz, and 3 GHz radio imaging (LoTSS, FIRST and VLASS) and spatially resolved ionized gas characteristics (SDSS IV-MaNGA) for 140 local ($z<0.1$) early-type "red geyser" galaxies. These galaxies have low star…

We report on two surveys of radio-weak AGN to look for radio variability. We find significant variability with an RMS of 10-20% on a timescale of months in radio-quiet and radio-intermediate quasars. This exceeds the variability of radio…

We have formed a complete sample of 26 low redshift (z < 0.3) giant radio galaxies (GRGs) from the WENSS survey, selected at flux densities above 1 Jy at 325 MHz. We present 10.5-GHz observations with the 100-m Effelsberg telescope of 18…

I present low-frequency observations of the lobes of the microquasar GRS 1758-258, which, together with earlier radio observations, provide the best constraints yet on the lobe spectra, and show that they are consistent with the electron…

We examine the remnant phase of radio galaxies using three-dimensional hydrodynamical simulations of relativistic jets propagating through cluster environments. By switching the jets off once the lobes have reached a certain length we can…

We discuss how the interaction between the electrons in a relativistic jet and the Cosmic Microwave Background (CMB) affects the observable properties of radio-loud AGN at early epochs. At high z the magnetic energy density in the radio…

We have carried out relativistic three-dimensional simulations of high-power radio sources propagating into asymmetric cluster environments. We offset the environment by 0 or 1 core radii (equal to 144 kpc), and incline the jets by 0, 15,…

Measuring the environments of massive galaxies at high redshift is crucial to understanding galaxy evolution and the conditions that gave rise to the distribution of matter we see in the Universe today. While high-$z$ radio galaxies…

I present an overview of past, present and future research on microquasars and jets, showing that microquasars, i.e. galactic jet sources, are among the best laboratories for high energy phenomena. After remindind the analogy with quasars,…

Over the past few years, we have been collecting data with the Nordic Optical Telescope (NOT) on the galaxy environments around active galactic nuclei (AGN). Here we present some results from a sample of 21 radio-loud and 20 radio-quiet…

Using ROSAT observations, we estimate gas pressures in the X-ray-emitting medium surrounding 63 FRII radio galaxies and quasars. We compare these pressures with the internal pressures of the radio-emitting plasma estimated by assuming…

The knowledge of the physical conditions occurring in the relativistic jet of radio-loud active galactic nuclei (AGNs) is important to understand the mechanisms at the basis of their multiband emission. From parsec-scale radio observations…