I will present results of studying the parsec-scale jets of the three most famous blazars from the 3C catalog, 3C279, 3C273, and 3C454.3, from the earliest days of VLBI up to the most recent highest resolution observations. I will discuss properties of jets (kinematics, timescales of variability,
magnetic field, jet contents, and jet environment) and stress the importance of radio monitoring...
The very bright, active quasars 3C 273, 3C 279, and 3C 345 are key objects in variability studies across the electromagnetic spectrum, and the first report of large fractional variations in radio emission in 1965 was based on observations of these 3 sources obtained with the University of Michigan 26-meter paraboloid. These structurally-complex 3C objects were subsequently monitored for over...
We report the results of the decade-long (2008--2018) monitoring of the blazar 3C 279 from $\gamma$-rays to 1 GHz radio frequencies, including Fermi and Swift data, obtained within the frames of an intensive GASP-WEBT collaboration campaign as well as polarimetric and spectroscopic data, collected during the same time interval. We have found that: 1) the X-ray and $\gamma$-ray light...
In this contribution, I will present the results of a paper on the Flat Spectrum Radio Quasar 3C 279. We use light curves that cover a time-frame of six years, at different wavelengths: Gamma-rays, X-rays, UV 3000 Å continuum, optical V band, Near-Infrared (NIR) JHK bands, 1mm, as well as optical spectropolarimetry. By applying cross-correlation analysis, We find that the UV continuum,...
Consistent multiwavelength observations of the blazar 3C 279 can be attributed at least in part to the legacy of the Third Cambridge Catalogue. The monitoring campaign during Dec 2013 discovered a very bright, 12-hour, orphan gamma-ray flare with a uniquely hard FermiLAT spectrum and high Compton dominance. We apply a novel theoretical model in the one-zone, leptonic tradition, which now...
We probe jets kinematics in 11 radio-loud AGN without relying on multi-epoch VLBI kinematics analysis. The method is based on measuring multi-frequency total flux density time delay and core shift in the jets. Our estimates of the apparent jet speed are consistent with the highest velocities seen by VLBI. We derive Doppler factors, Lorentz factors and viewing angles of the jets, as well as the...
There is compelling observational evidence that an emerging group of
compact radio galaxies, which lack of extended radio emission,
dominate in number the radio-loud AGN population in the local Universe. We call
these sources 'FR0' in opposition to the other Fanaroff-Riley classes
to emphasize their lack of prominent extended radio emission. They
are compact on a scale of < 5 kpc, within the...
The discovery of diffuse optical and X-ray synchrotron emission in a number of low-power radio hotspot requires a revision of the standard scenario of particles accelerated by a single strong shock generated at the jet termination. High energy electrons like those responsible for the X-ray emission should arise from very small regions because their short lifetime should limit their emission to...
We present an imaging and spectral analysis of Chandra data for the radio galaxy 3C 187 (z = 0.465). The diffuse X-ray emission around 3C 187 in the 0.5-3 keV band is found to extend up to ~ 900 kpc along the radio lobe direction and ~ 700 kpc in the cross-cone direction. Spectral X-ray analysis in combination with radio data yields a possible interpretation of the emission observed in the...
The third Cambridge catalogue (3C) includes several sources detected at gamma-ray energies. While blazars outnumber radio galaxies in the Fermi Large Area Telescope (LAT) catalogues by nearly two orders of magnitudes, counts are more balanced among the bright, steep spectrum sources composing the 3C. Starting with a focus on the gamma-ray detected 3C radio galaxies, we will present a summary...
Unification suggests that Blazars are beamed, jet-on oriented radio-galaxies.
The phenomenological distinction between Blazars and Radiogalaxies was originally established before gamma-ray observations revealed efficient Compton-cooling in Blazars. A growing sample of radio-galaxies with extended jets that do not appear highly beamed in radio-studies have been detected at very high gamma-ray...
