1,468 research outputs found
Nearby radio loud AGN and the Unified Model
The statistical study of the parsec scale properties of radio sources is
crucial to get information on the nature of the central engine and to provide
the foundations of the current unified theories, suggesting that the appearance
of active galactic nuclei depends strongly on orientation. We started a project
to observe at sub-arcsec resolution a complete sample of 94 nearby (z<0.1)
radio galaxies, the Bologna Complete Sample, which is not affected by any
selection effect on the jet velocity and orientation with respect to the line
of sight. Up to now, we published our parsec scale analysis of 77/94 sources.
Here, we describe the last VLBA observations at 5 GHz and EVN data at 18 cm
obtained for the 17 remaining faintest radio core (<5 mJy at 5 GHz in VLA
images) BCS sources and we report our preliminary results on the whole complete
sample.Comment: 4 pages, 1 figure; accepted for publication in the proceeding of the
"12th European VLBI Network Symposium and Users Meeting - EVN 2014" (7-10
October 2014, Cagliari, Italy); published online in Proceedings of Science,
PoS(EVN 2014)09
B2 1144+35B, a giant low power radio galaxy with superluminal motion. Orientation and evidence for recurrent activity
The goal of this work is a detailed study of the nearby, low power radio
galaxy B2 1144+35B. For this purpose, we performed new Very Long Baseline Array
(VLBA) and Very Large Array (VLA) observations. This source has several
properties (bright, nearby, large range of spatial structures, visible
counterjet, etc.) that make it an excellent astrophysical laboratory for the
study of the evolution of radio jets. Here we report the detection of motion in
the counterjet at 0.23 0.07 c, which allows us to estimate the
orientation of the parsec-scale jet at 33 from the line of
sight, with an intrinsic velocity of (0.94)c. We also report
on a brightening of the core at high frequencies which we suggest could be the
result of a new component emerging from the core. High dynamic range VLBA
observations at 5 GHz reveal, for the first time, extended emission connecting
the core with the bright complex of emission that dominates the flux density of
the parsec scale structure at frequencies below 20 GHz. The evolution of this
bright complex is considered and its slow decline in flux density is
interpreted as the result of an interaction with the interstellar medium of the
host galaxy.Comment: 7 pages, 6 b&w figures. A&A in pres
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