Hosts of Powerful Radio Galaxies in the Near‐Infrared: Implications for Radio Source Evolution

1998 ◽  
Vol 503 (1) ◽  
pp. 156-167 ◽  
Author(s):  
W. H. de Vries ◽  
C. P. O'Dea ◽  
S. A. Baum ◽  
E. Perlman ◽  
M. D. Lehnert ◽  
...  
1999 ◽  
Vol 194 ◽  
pp. 241-245
Author(s):  
Philip Best ◽  
Huub Röttgering ◽  
Malcolm Longair

The results of a deep spectroscopic campaign on powerful radio galaxies with redshifts z ˜ 1, to investigate in detail their emission line gas properties, are presented. Both the 2-dimensional velocity structure of the [OII] 3727 emission line and the ionisation state of the gas are found to be strongly dependent upon the linear size (age) of the radio source in a manner indicative of the emission line properties of small (young) radio sources being dominated by the passage of the radio source shocks. The consequences of this evolution throughout the few x107 year lifetime of the radio source are discussed, particularly with relation to the alignment of the UV–optical continuum emission of these objects along their radio axis, the nature of which shows similar evolution.


Author(s):  
Guillaume Drouart ◽  
Nick Seymour ◽  
Tim J. Galvin ◽  
Jose Afonso ◽  
Joseph R. Callingham ◽  
...  

Abstract We present the results of a new selection technique to identify powerful ( $L_{\rm 500\,MHz} \gt 10^{27}\,\text{WHz}^{-1}$ ) radio galaxies towards the end of the Epoch of Reionisation. Our method is based on the selection of bright radio sources showing radio spectral curvature at the lowest frequency ( ${\sim}100\,\text{MHz}$ ) combined with the traditional faintness in K-band for high-redshift galaxies. This technique is only possible, thanks to the Galactic and Extra-galactic All-sky Murchison Wide-field Array survey which provides us with 20 flux measurements across the 70– $230\,\text{MHz}$ range. For this pilot project, we focus on the GAMA 09 field to demonstrate our technique. We present the results of our follow-up campaign with the Very Large Telescope, Australian Telescope Compact Array, and the Atacama Large Millimetre Array to locate the host galaxy and to determine its redshift. Of our four candidate high-redshift sources, we find two powerful radio galaxies in the $1<z<3$ range, confirm one at $z=5.55$ , and present a very tentative $z=10.15$ candidate. Their near-infrared and radio properties show that we are preferentially selecting some of the most radio luminous objects, hosted by massive galaxies very similar to powerful radio galaxies at $1<z<5$ . Our new selection and follow-up technique for finding powerful radio galaxies at $z>5.5$ has a high 25–50% success rate.


2006 ◽  
Vol 2 (S238) ◽  
pp. 365-366
Author(s):  
David Floyd ◽  
Marco Chiaberge ◽  
Eric S. Perlman ◽  
Bill Sparks ◽  
F. Duccio Macchetto ◽  
...  

AbstractThe 3CR catalogue provides a statistical sampling of the most powerful radio galaxies out to z ∼ 0.3. Over the decade and a half of Hubble observations we have amassed a major multi-wavelength dataset on these sources, discovering amongst other things, new jets, hotspots, dust disks, and faint point-like nuclei. We present here the results of our latest snapshot survey, a near-complete sampling of the 3CR host galaxies at z < 0.3 in the near-IR (H-band). This un-extinguished view of the host galaxies has provided us with an accurate measure of the stellar/spheroid masses of the sources, and an unbiased view of their morphologies. We show that they exhibit an identical Kormendy relation to nearby QSO's and the massive Elliptical population, but are distinct from the Brightest Cluster Members, and mergers. We find that while a few sources exhibit signs of a recent or impending major merger, many more sources have remnants consistent with a gas-rich minor merger in their recent history. We detect unresolved nuclear sources in most (∼80%) of FRI, with their IR luminosities correlating linearly with radio core power. This implies that the IR nuclei are synchrotron radiation produced at the base of the relativistic jet, and confirms that no infrared (thermal) radiation in excess to synchrotron is present in FRIs, unlike in other classes of AGN.


2017 ◽  
Vol 599 ◽  
pp. A123 ◽  
Author(s):  
N. P. H. Nesvadba ◽  
C. De Breuck ◽  
M. D. Lehnert ◽  
P. N. Best ◽  
C. Collet

We present VLT/SINFONI imaging spectroscopy of the rest-frame optical emission lines of warm ionized gas in 33 powerful radio galaxies at redshifts z ≳ 2, which are excellent sites to study the interplay of rapidly accreting active galactic nuclei and the interstellar medium of the host galaxy in the very late formation stages of massive galaxies. Our targets span two orders of magnitude in radio size (2−400 kpc) and kinetic jet energy (a few 1046– almost 1048 erg s-1). All sources have complex gas kinematics with broad line widths up to ~1300 km s-1. About half have bipolar velocity fields with offsets up to 1500 km s-1 and are consistent with global back-to-back outflows. The others have complex velocity distributions, often with multiple abrupt velocity jumps far from the nucleus of the galaxy, and are not associated with a major merger in any obvious way. We present several empirical constraints that show why gas kinematics and radio jets seem to be physically related in all galaxies of the sample. The kinetic energy in the gas from large scale bulk and local outflow or turbulent motion corresponds to a few 10-3 to 10-2 of the kinetic energy output of the radio jet. In galaxies with radio jet power ≳ 1047 erg s-1, the kinetic energy in global back-to-back outflows dominates the total energy budget of the gas, suggesting that bulk motion of outflowing gas encompasses the global interstellar medium. This might be facilitated by the strong gas turbulence, as suggested by recent analytical work. We compare our findings with recent hydrodynamic simulations, and discuss the potential consequences for the subsequent evolution of massive galaxies at high redshift. Compared with recent models of metal enrichment in high-z AGN hosts, we find that the gas-phase metallicities in our galaxies are lower than in most low-z AGN, but nonetheless solar or even super-solar, suggesting that the ISM we see in these galaxies is very similar to the gas from which massive low-redshift galaxies formed most of their stars. This further highlights that we are seeing these galaxies near the end of their active formation phase.


1988 ◽  
Vol 230 (1) ◽  
pp. 131-160 ◽  
Author(s):  
R. M. Prestage ◽  
J. A. Peacock

1989 ◽  
Vol 134 ◽  
pp. 562-564
Author(s):  
G. Burbidge ◽  
A. Hewitt

In the 1950s, V.A. Ambartsumian (1958) proposed that galaxies result from explosive processes in galactic centers. Soon after the discovery of powerful radio galaxies in this same period, it became clear that explosive ejection of gas and relativistic particles was a common feature of active galaxies (Burbidge, Burbidge and Sandage 1963).


2010 ◽  
Vol 187 (1) ◽  
pp. 1-63 ◽  
Author(s):  
Ruth A. Daly ◽  
Preeti Kharb ◽  
Christopher P. O'Dea ◽  
Stefi A. Baum ◽  
Matthew P. Mory ◽  
...  

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