The optical properties of low luminosity radio galaxies with radio jets

1993 ◽  
Vol 105 ◽  
pp. 1710 ◽  
Author(s):  
J. I. Gonzalez-Serrano ◽  
R. Carballo ◽  
I. Perez-Fournon
Keyword(s):  
Optical Properties ◽  
Radio Galaxies ◽  
Radio Jets

Optical Properties of High Redshift Radio Galaxies

1989 ◽  
pp. 543-545 ◽  
Author(s):  
Patrick J. McCarthy ◽  
Hyron Spinrad ◽  
Wil van Breugel
Keyword(s):  
Optical Properties ◽  
High Redshift ◽  
Radio Galaxies

scholarly journals The morphological classification of distant radio galaxies explored with three-dimensional simulations

2019 ◽  
Vol 490 (1) ◽  
pp. 1363-1382 ◽  
Author(s):  
Michael D Smith ◽  
Justin Donohoe
Keyword(s):  
Radio Galaxy ◽  
Three Dimensional ◽  
Radio Galaxies ◽  
Morphological Classification ◽  
Helical Structures ◽  
Radio Jets ◽  
Source Type ◽  
Radio Lobe ◽  
Three Dimensional Simulations

ABSTRACT We explore the observational implications of a large systematic study of high-resolution three-dimensional simulations of radio galaxies driven by supersonic jets. For this fiducial study, we employ non-relativistic hydrodynamic adiabatic flows from nozzles into a constant pressure-matched environment. Synchrotron emissivity is approximated via the thermal pressure of injected material. We find that the morphological classification of a simulated radio galaxy depends significantly on several factors with increasing distance (i.e. decreasing observed resolution) and decreasing orientation often causing reclassification from FR II (limb-brightened) to FR I (limb-darkened) type. We introduce the Lobe or Limb Brightening Index (LBI) to measure the radio lobe type more precisely. The jet density also has an influence as expected with lower density leading to broader and bridged lobe morphologies as well as brighter radio jets. Hence, relating observed source type to the intrinsic jet dynamics is not straightforward. Precession of the jet direction may also be responsible for wide relaxed sources with lower LBI and FR class as well as for X-shaped and double–double structures. Helical structures are not generated because the precession is usually too slow. We conclude that distant radio galaxies could appear systematically more limb darkened due to merger-related redirection and precession as well as due to the resolution limitation.

scholarly journals The nuclear radio-optical properties of intermediate-redshift FR II radio galaxies and quasars

2004 ◽  
Vol 428 (2) ◽  
pp. 401-408 ◽  
Author(s):  
S. Varano ◽  
M. Chiaberge ◽  
F. D. Macchetto ◽  
A. Capetti
Keyword(s):  
Optical Properties ◽  
Radio Galaxies ◽  
Intermediate Redshift

scholarly journals The AGN fuelling/feedback cycle in nearby radio galaxies – III. 3D relative orientations of radio jets and CO discs and their interaction

2020 ◽  
Vol 499 (4) ◽  
pp. 5719-5731
Author(s):  
Ilaria Ruffa ◽  
Robert A Laing ◽  
Isabella Prandoni ◽  
Rosita Paladino ◽  
Paola Parma ◽  
...  
Keyword(s):  
Radio Galaxies ◽  
Extensive Study ◽  
3D Analysis ◽  
Very Large Array ◽  
Radio Jets ◽  
Rotation Axes ◽  
Feedback Cycle ◽  
Wide Range ◽  
Disc Rotation ◽  
First Time

ABSTRACT This is the third paper of a series exploring the multifrequency properties of a sample of eleven nearby low-excitation radio galaxies (LERGs) in the southern sky. We are conducting an extensive study of different galaxy components (stars, dust, warm and cold gas, radio jets) with the aim of better understanding the AGN fuelling/feedback cycle in LERGs. Here, we present new, deep, sub-kpc resolution Karl G. Jansky Very Large Array (JVLA) data for five sample sources at 10 GHz. Coupling these data with previously acquired Atacama Large Millimetre/submillimetre Array (ALMA) CO(2–1) observations and measurements of comparable quality from the literature, we carry out for the first time a full 3D analysis of the relative orientations of jet and disc rotation axes in six FR I LERGs. This analysis shows (albeit with significant uncertainties) that the relative orientation angles span a wide range (≈30○–60○). There is no case where both axes are accurately aligned and there is a marginally significant tendency for jets to avoid the disc plane. Our study also provides further evidence for the presence of a jet-CO disc interaction (already inferred from other observational indicators) in at least one source, NGC 3100. In this case, the limited extent of the radio jets, along with distortions in both the molecular gas and the jet components, suggest that the jets are young, interacting with the surrounding matter and rapidly decelerating.

scholarly journals On the Environments of Giant Radio Galaxies

2021 ◽  
Author(s):  
Ting-Wen Lan ◽  
J Xavier Prochaska
Keyword(s):  
Large Scale ◽  
Radio Galaxies ◽  
Sloan Digital Sky Survey ◽  
Host Galaxies ◽  
Homogeneous Sample ◽  
Large Scale Structures ◽  
Radio Jets ◽  
Sky Survey ◽  
Scale Structures ◽  
Control Samples

Abstract We test the hypothesis that environments play a key role in enabling the growth of enormous radio structures spanning more than 700 kpc, an extreme population of radio galaxies called giant radio galaxies (GRGs). To achieve this, we explore (1) the relationships between the occurrence of GRGs and the surface number density of surrounding galaxies, including satellite galaxies and galaxies from neighboring halos, as well as (2) the GRG locations towards large-scale structures. The analysis is done by making use of a homogeneous sample of 110 GRGs detected from the LOFAR Two-metre Sky Survey in combination with photometric galaxies from the DESI Legacy Imaging Surveys and a large-scale filament catalog from the Sloan Digital Sky Survey. Our results show that the properties of galaxies around GRGs are similar with that around the two control samples, consisting of galaxies with optical colors and luminosity matched to the properties of the GRG host galaxies. Additionally, the properties of surrounding galaxies depend on neither their relative positions to the radio jet/lobe structures nor the sizes of GRGs. We also find that the locations of GRGs and the control samples with respect to the nearby large-scale structures are consistent with each other. These results demonstrate that there is no correlation between the GRG properties and their environments traced by stars, indicating that external galaxy environments are not the primary cause of the large sizes of the radio structures. Finally, regarding radio feedback, we show that the fraction of blue satellites does not correlate with the GRG properties, suggesting that the current epoch of radio jets have minimal influence on the nature of their surrounding galaxies.

scholarly journals Gas kinematics in powerful radio galaxies atz~ 2: Energy supply from star formation, AGN, and radio jets

2017 ◽  
Vol 600 ◽  
pp. A121 ◽  
Author(s):  
N. P. H. Nesvadba ◽  
G. Drouart ◽  
C. De Breuck ◽  
P. Best ◽  
N. Seymour ◽  
...  
Keyword(s):  
Star Formation ◽  
Energy Supply ◽  
Radio Galaxies ◽  
Powerful Radio ◽  
Gas Kinematics ◽  
Radio Jets

scholarly journals All-sky catalog of local radio galaxies

2012 ◽  
Vol 8 (S295) ◽  
pp. 271-271
Author(s):  
S. van Velzen ◽  
H. Falcke
Keyword(s):  
Black Hole ◽  
Cosmic Rays ◽  
Galaxy Formation ◽  
Causal Relation ◽  
Radio Galaxies ◽  
High Energy ◽  
Local Universe ◽  
High Energy Cosmic Rays ◽  
Normal Galaxies ◽  
Radio Jets

AbstractThe final episode in the history of black hole accretion and galaxy formation takes place in our cosmic backyard, the local universe. Within this volume must also reside the — until now unknown — sources of observed ultra-high energy cosmic rays (UHECRs). A thorough study of the local universe requires full-sky coverage to obtain a sizable sample and map the matter anisotropy. We recently constructed the first catalog of radio-emitting galaxies that meets this requirement. The sample contains all radio galaxies similar to Centaurus~A out to ~100 Mpc. Only 3% of the hosts of the powerful radio jets are classified as Spiral galaxies, while for non-radio galaxies of similar mass, this fraction is 34%. The energy injected by radio jets per unit volume indicates that Cen A-like radio galaxies have in principle sufficient power to accelerate cosmic rays to ultra-high energies. A significantly enhanced clustering of radio-loud galaxies compared to normal galaxies of the same luminosity is observed. This indicates a causal relation between galaxy environment and jet power, independent of black hole mass.

Life-cycles & Energetics of Radio-Loud AGN

2018 ◽  
Vol 14 (S342) ◽  
pp. 122-126
Author(s):  
V. H. Mahatma ◽  
M. J. Hardcastle ◽  
Keyword(s):  
Large Scale ◽  
Cosmic Time ◽  
Mass Function ◽  
Radio Galaxies ◽  
Life Cycles ◽  
Cluster Center ◽  
Qualitative And Quantitative ◽  
Radio Jets ◽  
The Galaxy ◽  
Jet Power

AbstractRadio jets are the large-scale and extragalactic footprints of accretion onto supermassive black holes, and are suggested to be the key ingredient controlling the galaxy stellar mass function. Of particular importance is their jet power - the time-averaged energetic feedback into their environment. Hence, the dynamics, energetics and life-cycles of radio-loud AGN (RLAGN) must be understood in order to build a qualitative and quantitative picture of their impact over cosmic time. Here, we present a study of the spectral age of two powerful, cluster-center radio galaxies, and compare with an analytic model to robustly determine their jet powers. We also present some recent LOFAR observations of the different phases of RLAGN activity, namely the remnant and subsequent restarting phases, which are key to understanding the dynamics of RLAGN over their total lifetime.

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