Host Galaxies of Radio-Loud & Radio-Quiet AGN

1996 ◽  
Vol 175 ◽  
pp. 248-249
Author(s):  
M.J. Kukula ◽  
J.S. Dunlop ◽  
G.L. Taylor ◽  
D.H. Hughes
Keyword(s):  
Radio Galaxies ◽  
Active Galaxy ◽  
Clear Understanding ◽  
Host Galaxies ◽  
Orientation Effects ◽  
Radio Power

A clear understanding of both the differences and similarities between the host galaxies of the three main classes of powerful active galaxy – radio-quiet quasars (RQQs), radio-loud quasars (RLQs) and radio galaxies (RGs) – is vital in any attempt to unify or relate the various manifestations of the AGN phenomenon. The unification of RLQs and RGs via orientation effects requires that the hosts of the two types be derived from the same population of galaxies. Meanwhile, the correlation between radio power and host morphology in nearby AGN, with radio-quiet objects (Seyferts) occurring in disc systems and radio-loud sources in ellipticals, is generally assumed to persist at higher redshifts and nuclear luminosities. However, in both cases the evidence remains ambiguous and, moreover, many previous studies have been based on poorly selected samples.

scholarly journals WATCAT: a tale of wide-angle tailed radio galaxies

2019 ◽  
Vol 626 ◽  
pp. A8 ◽  
Author(s):  
V. Missaglia ◽  
F. Massaro ◽  
A. Capetti ◽  
M. Paolillo ◽  
R. P. Kraft ◽  
...  
Keyword(s):  
Radio Galaxies ◽  
Sloan Digital Sky Survey ◽  
Host Galaxy ◽  
Wide Angle ◽  
Host Galaxies ◽  
Very Large Array ◽  
Sky Survey ◽  
Black Hole Masses ◽  
Extended Emission ◽  
Radio Power

We present a catalog of 47 wide-angle tailed radio galaxies (WATs), the WATCAT, mainly built including a radio morphological classification; WATs were selected by combining observations from the National Radio Astronomy Observatory/Very Large Array Sky Survey (NVSS), the Faint Images of the Radio Sky at Twenty-Centimeters (FIRST), and the Sloan Digital Sky Survey (SDSS). We included in the catalog only radio sources showing two-sided jets with two clear “warmspots” (i.e., jet knots as bright as 20% of the nucleus) lying on the opposite side of the radio core, and having classical extended emission resembling a plume beyond them. The catalog is limited to redshifts z ≤ 0.15, and lists only sources with radio emission extended beyond 30 kpc from the host galaxy. We found that host galaxies of WATCAT sources are all luminous (−20.5 ≳ Mr ≳ −23.7), red early-type galaxies with black hole masses in the range 108 ≲ MBH ≲ 109 M⊙. The spectroscopic classification indicates that they are all low-excitation galaxies (LEGs). Comparing WAT multifrequency properties with those of FR I and FR II radio galaxies at the same redshifts, we conclude that WATs show multifrequency properties remarkably similar to FR I radio galaxies, having radio power of typical FR IIs.

scholarly journals Optical and IR Properties of Radio Galaxies as a Function of their Radio Power

1996 ◽  
Vol 171 ◽  
pp. 414-414
Author(s):  
L. Maxfield ◽  
S.G. Djorgovski ◽  
D. Thompson ◽  
M.A. Pahre ◽  
R.R. de Carvalho ◽  
...  
Keyword(s):  
High Redshift ◽  
Spectroscopic Properties ◽  
Radio Galaxies ◽  
Active Nucleus ◽  
Data Set ◽  
Uv Emission ◽  
Two Samples ◽  
Order Of Magnitude ◽  
Ir Photometry ◽  
Radio Power

We compare optical and infrared photometric and spectroscopic properties of high-redshift radio galaxies from the 3CR and B3 surveys. At a given redshift and a fixed restframe frequency, the two samples differ on average by an order of magnitude in radio power, thus providing a fair baseline in radio powerfor a range of redshifts. We present new optical and IR photometry and spectrosopy for a number of B3 sources. We combine these data with the existing corresponding information on B3 and 3CR sources, in order to explore different correlations of source properties with redshift, and among themselves. B3 sources follow the same trend as 3CR's in the K band Hubble diagram, although they do seem to be slightly fainter on average at a given redshift. This trend is slightly more prominent in the Gunn r band. This suggests that some fraction of the observed light in the r and K bands is contributed by an active nucleus, which also powers the radio lobes. The B3's also tend to have lower emission line luminosities than 3CR's at any given redshift, suggesting that there may be a correlation between line luminosity and radio power. Such a correlation is clearly seen and is followed by both samples. It suggests that the UV emission lines are largely powered by the active nucleus, ostensibly a hidden quasar, which is also responsible for the radio emission. We also examine the behavior of the optical and radio PA alignments for the combined B3+3CR data set. We find that high-power and high-redshift subsamples for both B3's and 3CR's show the alignments more prominently, but we still cannot tell which of these variables dominates this effect. This work was supported in part by the NSF PYI award AST-9157412, and the Bressler Foundation.

scholarly journals A comparative HST imaging study of the host galaxies of radio-quiet quasars, radio-loud quasars and radio galaxies -- I

1999 ◽  
Vol 308 (2) ◽  
pp. 377-404 ◽  
Author(s):  
R. J. McLure ◽  
M. J. Kukula ◽  
J. S. Dunlop ◽  
S. A. Baum ◽  
C. P. O'Dea ◽  
...  
Keyword(s):  
Imaging Study ◽  
Radio Galaxies ◽  
Host Galaxies ◽  
Quasars And Radio Galaxies

scholarly journals Deep spectroscopy of z  1 6C radio galaxies -- II. Breaking the redshift--radio power degeneracy

2002 ◽  
Vol 337 (4) ◽  
pp. 1407-1416 ◽  
Author(s):  
K. J. Inskip ◽  
P. N. Best ◽  
H. J. A. Rottgering ◽  
S. Rawlings ◽  
G. Cotter ◽  
...  
Keyword(s):  
Radio Galaxies ◽  
Radio Power

scholarly journals Radio Galaxies as Large-Scale Cosmological Probes

1988 ◽  
Vol 130 ◽  
pp. 579-579
Author(s):  
J.A. Peacock ◽  
L. Miller ◽  
C.A. Collins ◽  
D. Nicholson ◽  
S. J. Lilly
Keyword(s):  
Large Scale ◽  
A Priori ◽  
Radio Galaxies ◽  
Elliptical Galaxies ◽  
Central Component ◽  
Selection Effects ◽  
Core Radius ◽  
Point Correlation ◽  
Point Correlation Function ◽  
Radio Power

We are working on an all-sky sample of radio-selected elliptical galaxies to provide a powerful probe of clustering & streaming velocities on 10–100 Mpc scales. Our eventual sample will have the limits (i) S>0.5 Jy at 1.4 GHz; (ii) 0.01<z<0.1; (iii) |b| >15°; about 400 galaxies satisfy these criteria. We are pursuing an optical programme to obtain (i) B & I CCD frames for all galaxies; (ii) spectra for the galaxies without accurate redshifts; this is now about 30% complete. Accurate optical luminosity indicators exist for radio galaxies, without needing to measure velocity dispersions (using the correlations with optical core radius and radio central-component luminosity: Hoessel 1980: Ap. J. 241, 493; Fabbiano et al. 1984: Ap. J. 277, 115). We therefore expect to provide an accurate test of the Rubin-Ford effect, and to extend such studies to higher redshift. We also have a preliminary result for the 3D two-point correlation function of radio galaxies (see Figure). This strong clustering signal is seen only from galaxies in the decade of radio power below the Fanaroff-Riley division. These objects are known a priori to lie in cluster environments of average Abell richness 0 (Longair & Seldner 1979: MNRAS 189, 433). This result therefore provides confirmation of a trend of clustering with richness independent of optical selection effects in choosing a cluster sample.

scholarly journals VLBI Cores in a Sample of Radio Galaxies

1988 ◽  
Vol 129 ◽  
pp. 75-76
Author(s):  
G. Comoretto ◽  
L. Feretti ◽  
G. Giovannini
Keyword(s):  
Statistical Study ◽  
Dynamic Range ◽  
Total Sample ◽  
Radio Galaxies ◽  
Log P ◽  
Complete Sample ◽  
Radio Structure ◽  
First Results ◽  
5 Ghz ◽  
Radio Power

We present the first results of a statistical study of the milliarcsec structure in a complete sample of radio galaxies. We have selected from the B2 and 3CR samples of galaxies the sources which present, at the VLA or WSRT angular resolution, an unresolved core with a flux density at 5 GHz Sc ≥ 100 mJy. The total sample consists of 30 radio galaxies, 17 from the B2 and 13 from the 3CR catalog. This complete sample covers a range of total radio power at 408 MHz log P = 23.5 – 26.5 W/Hz (low-intermediate luminosity). The radio structure of these sources on the arcsec-arcmin scale is well known, thanks to good dynamic range VLA and/or WSRT maps; a large variety of structures is present in the sample, from classical doubles to head-tail sources; flat, inverted and steep spectrum cores are also present.

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.

Sign in / Sign up

Export Citation Format

Share Document