Related papers: Studies on slow radio transients
The radio-loud AGN unification model associates powerful radio galaxies with radio-loud quasars and blazars. In analogy with the radio-quiet scheme, the nuclear regions of objects showing only narrow emission lines in their optical spectrum…
A wide-frequency radio study of Active Galactic Nuclei (AGN) is crucial to evaluate the intervening radiative mechanisms responsible for the observed emission and relate them with the underlying accretion physics. We present wide frequency…
Gigahertz Peaked Spectrum (GPS) sources form a key element in the study of the onset and evolution of radio-loud AGN, since they are most likely the young counterparts of extended radio sources. Here we discuss space-VLBI observations of…
We highlight some of the principal results from our recent Hubble Space Telescope studies of quasars and radio galaxies. The hosts of these powerful AGN are normal massive ellipticals which lie on the region of the fundamental plane…
Observational searches for intermediate-mass black holes (IMBHs; $10^2 - 10^6$ $M_\odot$) include relatively isolated dwarf galaxies. For those that host active galactic nuclei (AGNs), the IMBH nature may be discerned through the accretion…
We present our very recent results on the sub-mJy radio source populations at 1.4 GHz based on the Extended Chandra Deep Field South VLA survey, which reaches ~ 30 {\mu}Jy, with details on their number counts, evolution, and luminosity…
We measure the merger fraction of Type 2 radio-loud and radio-quiet active galactic nuclei at z>1 using new samples. The objects have HST images taken with WFC3 in the IR channel. These samples are compared to the 3CR sample of radio…
We have used Kepler photometry to characterize variability in four radio-loud active galactic nuclei (three quasars and one object tentatively identified as a Seyfert 1.5 galaxy) on timescales from minutes to months, comparable to the light…
This paper describes an investigation of the early evolution of extragalactic radio sources using samples of faint and bright Gigahertz Peaked Spectrum (GPS) and Compact Steep Spectrum (CSS) radio galaxies. Correlations found between their…
We present the results from 685 MHz observations with the upgraded Giant Metrewave Radio Telescope (uGMRT) of 22 quasars belonging to the Palomar-Green (PG) quasar sample. Only four sources reveal extended radio structures on $\sim$10-30…
The radio jets of an active galactic nucleus (AGN) can heat up the gas around a host galaxy and quench star formation activity. The presence of a radio jet could be related to the evolutionary path of the host galaxy and may be imprinted in…
Active Galactic Nuclei (AGN) are known to show flux variability over all observable timescales and across the entire electromagnetic spectrum. Over the past decade, a growing number of sources have been observed to show dramatic flux and…
Active Galactic Nuclei (AGN) can be probed by at different regions of the electromagnetic spectrum: e.g., radio observations reveal the nature of their relativistic jets and their magnetic fields, and complementarily, X-ray observations…
The changing-look active galactic nucleus (CL-AGN), an extraordinary subpopulation of supermassive black holes, has attracted growing attention for understanding its nature. We present an analysis of the spectral properties of 203…
Analysis of the frequency and physical properties of galaxies with star-formation and AGN activity in different environments in the local universe is a cornerstone for understanding structure formation and galaxy evolution. We have built a…
Only a small fraction of observed Active Galactic Nuclei display large-scale radio emission associated with jets, yet these radio-loud AGN have become increasingly important in models of galaxy evolution. In determining the dynamics and…
We present an analysis of the AGN broad-line regions of 6 powerful radio galaxies at z>~2 (HzRGs) with rest-frame optical imaging spectroscopy obtained at the VLT. All galaxies have luminous (L(H-alpha)=few x 10^44 erg s^-1), spatially…
We extend the study of the radio emission in early-type galaxies (ETGs) in the nearby Universe (recession velocity <7,500 km/s) as seen by the 150 MHz Low-Frequency ARray (LOFAR) observations and extend the sample from giant ETGs to massive…
In this review the correlations between host galaxy properties and black-hole mass determined from nearby quiescent galaxies are briefly discussed, before proceeding to investigate their application to active galactic nuclei (AGN). The…
We have studied the host galaxies of a sample of radio-loud AGN spanning more than four decades in the energy output of the nucleus. The core sample includes 40 low-power sources (BL Lac objects) and 22 high-power sources (radio-loud…