Related papers: Restarting activity in radio galaxies

We present deep GMOS-S/Gemini optical broad-band images for a complete sample of 46 southern 2Jy radio galaxies at intermediate redshifts (0.05<z<0.7). The high-quality observations show for the first time that the overall majority of PRGs…

The Shapley Concentration ($z\approx0.048$) covers several degrees in the Southern Hemisphere, and includes galaxy clusters in advanced evolutionary stage, groups of clusters in the early stages of merger, fairly massive clusters with…

NGC 613 (AM 0132-294) is a multi armed spiral with an active nucleus. Radio emission is aligned along the narrow inner bar of the spiral and appears to include inner and outer pairs of radio sources which define a line of ejection from this…

Multi-wavelength observations made in the last decade suggest that the universe underwent an intense phase of star formation in the past (z > 1). This intensive activity is commonly attributed to a higher galaxy merger rate when the…

We extend our study of the nuclei of 3CR FR II radio galaxies through HST optical images up to z=0.3. In the majority of them an unresolved nucleus (central compact core, CCC) is found. We analyze their position in the plane formed by the…

The Dragonfly Galaxy (MRC0152-209), at redshift z~2, is one of the most vigorously star-forming radio galaxies in the Universe. What triggered its activity? We present ALMA Cycle 2 observations of cold molecular CO(6-5) gas and dust, which…

In this paper we present the results of VLBI observations of six radio galaxies belonging to the 2-Jy sample. The selected objects are 3C17, PKS 0620-52, PKS 0625-35, PKS 1318-43, PKS 1333-33 and 3C317. The first is a high power radio…

We present a multi-wavelength investigation of the radio galaxy population in the galaxy cluster MOO J1506+5137 at $z$=1.09$\pm$0.03, which in previous work we identified as having multiple complex radio sources. The combined dataset used…

We present a radio and optical study of the double-double radio galaxy J1328+2752 based on new low-frequency GMRT observations and SDSS data. The radio data were used to investigate the morphology and to perform a spectral index analysis.…

We report the detection of outflowing molecular gas in the center of the nearby (z=0.014) massive radio galaxy NGC6328. The radio core of the galaxy, PKS B1718-649, is identified as a Gigahertz Peaked Spectrum source with a compact (2 pc)…

Dual-Active Galactic Nuclei (AGN) are a natural consequence of the hierarchical structure formation scenario, and can provide an important test of various models for black hole growth. However, due to their rarity and difficulty to find at…

We present sensitive, high dynamic range, Very Long Baseline Array (VLBA) polarimetric observations of the cores of three powerful radio galaxies: 3C166, 3C236 and 3C390.3. Significant polarization is detected in one source (3C166) allowing…

The existence of double-double radio galaxies (DDRGs) is evidence for recurrent jet activity in AGN, as expected from standard accretion models. A detailed study of these rare sources provides new perspectives for investigating the AGN duty…

We use $K-band imaging to investigate the angular size and morphology of 10 6C radio galaxies, at redshifts $1\leq z\leq 1.4$. Two appear to be undergoing mergers, another contains two intensity peaks aligned with the radio jets, while the…

Active galactic nuclei (AGN) at the centres of galaxies can cycle between periods of activity and of quiescence. Characterising the duty-cycle of AGN is crucial for understanding their impact on the evolution of the host galaxy. For radio…

So-called FR0 radio galaxies have recently emerged as a family of active galaxies with all the same properties as FRI radio galaxies except for their ratio of core to total emission which is about 30 times as high compared to FRI sources.…

Supermassive black holes at the centres of galaxies can cycle through periods of activity and quiescence. Characterising the duty cycle of active galactic nuclei is crucial for understanding the impact of the energy they release on the host…

We first review some basic properties of the most important classes of active galactic nuclei (AGN), including quasars, blazars, Seyfert galaxies and radio galaxies. The most commonly accepted type of scheme designed to individually unify…

Active galactic nuclei (AGNs) exhibit variability across the entire electromagnetic spectrum with distinct flaring episodes at different frequencies. The high sensitivity and nearly uniform sky coverage of the Large Area Telescope on board…

We present WSRT observations of the neutral hydrogen in the nearby radio galaxy B2 0648+27. In emission, we detect a very large amount of HI (M_HI = 1.1 x 10^10 M_sun) that is distributed in a very extended disk, or ring-like structure, of…