scholarly journals RC J0311+0507: A Candidate to Superpowerful Radio Galaxies with z = 4.514

2006 ◽  
Vol 2 (S235) ◽  
pp. 431-431
Author(s):  
A. I. Kopylov ◽  
Yu. N. Parijskij ◽  
N. S. Soboleva ◽  
A. V. Temirova ◽  
O. V. Verkhodanov ◽  
...  
Keyword(s):  
Radio Source ◽  
Radio Galaxies ◽  
Strong Line ◽  
Radio Luminosity ◽  
Spectrum Radio

AbstractThe investigations of the ultra steep spectrum radio source RC J0311+0507 (4C+04.11) in radio (RATAN-600, VLA) and optics (6-m telescope SAO RAS) are presented. The identification of a strong line at 6703 Å with Lyα gives a redshift z=4.514. The object belongs to the group of extremely distant radio galaxies of ultrahigh radio luminosity (P1400 = 1.3 × 1029WHz−1).

scholarly journals Low-luminosity BL Lac Objects and Flat-spectrum Radio Galaxies

1998 ◽  
Vol 164 ◽  
pp. 171-172
Author(s):  
M. Bondi ◽  
D. Dallacasa ◽  
M. J. M. Marchã ◽  
C. Stanghellini
Keyword(s):  
Radio Galaxies ◽  
Radio Luminosity ◽  
Bl Lac Objects ◽  
Spectrum Radio ◽  
Bl Lac ◽  
First Results

AbstractWe present first results from a new sample of low radio luminosity flat spectrum radio galaxies.

scholarly journals Radio Source Evolution Derived from Low Frequency Surveys

2002 ◽  
Vol 199 ◽  
pp. 50-53
Author(s):  
C.A. Jackson ◽  
J.V. Wall
Keyword(s):  
Radio Source ◽  
Luminosity Function ◽  
Low Frequency ◽  
Radio Galaxies ◽  
Parametric Models ◽  
Radio Luminosity ◽  
Space Density ◽  
Radio Data ◽  
Radio Luminosity Function

We find simple parametric models to describe the space density evolution of radio-loud AGN, treating FRI and FRII radio galaxies separately as the two parent populations in our dual-population unified scheme. In this we use low frequency radio data (v < 500 MHz), where radio samples are unbiased by Doppler beaming. Incorporated into this latest analysis is a new determination of the local radio luminosity function at 1.4 GHz from galaxies common to both the 2dFGRS and NVSS surveys.

scholarly journals Radio-optical Identification of Very-Steep Spectrum Radio Sources from the UTR-2 Catalogue

2002 ◽  
Vol 199 ◽  
pp. 217-218 ◽  
Author(s):  
H. Andernach ◽  
O.V. Verkhodanov ◽  
N.V. Verkhodanova
Keyword(s):  
Radio Source ◽  
High Redshift ◽  
Radio Galaxies ◽  
Image Databases ◽  
Radio Continuum ◽  
Radio Sources ◽  
Optical Identification ◽  
X Ray ◽  
Spectrum Radio

We used radio source catalogues accessible from the CATS database to establish radio continuum spectra for decametric radio sources in the UTR-2 catalogue. In an attempt to find further candidates for high-redshift radio galaxies, we searched the FIRST and NVSS surveys for counterparts of a sample of UTR sources with ultra-steep radio spectra (USS, α ≤ −1.2, S ∼ vα). We derived accurate positions and sizes for 23 of these USS sources. The search for optical counterparts from the APM (object) and DSS (image) databases, as well as infrared and X—ray identifications of these UTR sources are in progress.

scholarly journals Spatially resolved studies of extragalactic jets in high redshift radio galaxies

2014 ◽  
Vol 10 (S313) ◽  
pp. 231-235
Author(s):  
Leah K. Morabito ◽  
Adam Deller ◽  
J. B. R. Oonk ◽  
Huub Röttgering ◽  
George Miley
Keyword(s):  
High Redshift ◽  
Low Frequency ◽  
Radio Galaxies ◽  
Radio Sources ◽  
Spatially Resolved ◽  
Long Baseline ◽  
Early Results ◽  
Spectrum Radio ◽  
Extragalactic Jets ◽  
Frequency Survey

AbstractThe correlation between radio spectral steepness and redshift has been successfully used to find high redshift (z ⩾ 2) radio galaxies, but the origin of this relation is unknown. The ultra-steep spectra of high-z radio sources make them ideally suited for studies with the Low Band Antenna of the new Low Frequency Array, which covers 10–80 MHz and has baselines up to about 1300 km. As part of an ongoing survey, we use the longest baselines to map the low-frequency (< 70 MHz) spatial distributions along the jets of 5 bright extended steep spectrum high-z radio sources. From this, we will determine whether the spectra change over these spatially resolved sources, thereby constraining particle acceleration processes. We present early results from our low-frequency survey of ultra-steep spectrum radio galaxies. The first low frequency long baseline images of these objects are presented.

scholarly journals BROADBAND SPECTRAL MODELING OF THE EXTREME GIGAHERTZ-PEAKED SPECTRUM RADIO SOURCE PKS B0008-421

2015 ◽  
Vol 809 (2) ◽  
pp. 168 ◽  
Author(s):  
J. R. Callingham ◽  
B. M. Gaensler ◽  
R. D. Ekers ◽  
S. J. Tingay ◽  
R. B. Wayth ◽  
...  
Keyword(s):  
Radio Source ◽  
Spectral Modeling ◽  
Spectrum Radio

scholarly journals The XXL Survey

2019 ◽  
Vol 625 ◽  
pp. A111 ◽  
Author(s):  
Andrew Butler ◽  
Minh Huynh ◽  
Anna Kapińska ◽  
Ivan Delvecchio ◽  
Vernesa Smolčić ◽  
...  
Keyword(s):  
Galaxy Evolution ◽  
High Redshift ◽  
Radio Galaxies ◽  
Optical Data ◽  
Scaling Relation ◽  
Radio Luminosity ◽  
Hot Gas ◽  
Luminosity Functions ◽  
Wide Range ◽  
Luminosity Evolution

The evolution of the comoving kinetic luminosity densities (Ωkin) of the radio loud high-excitation radio galaxies (RL HERGs) and the low-excitation radio galaxies (LERGs) in the ultimate XMM extragalactic survey south (XXL-S) field is presented. The wide area and deep radio and optical data of XXL-S have allowed the construction of the radio luminosity functions (RLFs) of the RL HERGs and LERGs across a wide range in radio luminosity out to high redshift (z = 1.3). The LERG RLFs display weak evolution: Φ(z)∝(1 + z)0.67 ± 0.17 in the pure density evolution (PDE) case and Φ(z)∝(1 + z)0.84 ± 0.31 in the pure luminosity evolution (PLE) case. The RL HERG RLFs demonstrate stronger evolution than the LERGs: Φ(z)∝(1 + z)1.81 ± 0.15 for PDE and Φ(z)∝(1 + z)3.19 ± 0.29 for PLE. Using a scaling relation to convert the 1.4 GHz radio luminosities into kinetic luminosities, the evolution of Ωkin was calculated for the RL HERGs and LERGs and compared to the predictions from various simulations. The prediction for the evolution of radio mode feedback in the Semi-Analytic Galaxy Evolution (SAGE) model is consistent with the Ωkin evolution for all XXL-S RL AGN (all RL HERGs and LERGs), indicating that the kinetic luminosities of RL AGN may be able to balance the radiative cooling of the hot phase of the IGM. Simulations that predict the Ωkin evolution of LERG equivalent populations show similar slopes to the XXL-S LERG evolution, suggesting that observations of LERGs are well described by models of SMBHs that slowly accrete hot gas. On the other hand, models of RL HERG equivalent populations differ in their predictions. While LERGs dominate the kinetic luminosity output of RL AGN at all redshifts, the evolution of the RL HERGs in XXL-S is weaker compared to what other studies have found. This implies that radio mode feedback from RL HERGs is more prominent at lower redshifts than was previously thought.

scholarly journals The Milliarcsecond Core of 3C147 at 6 cm

1984 ◽  
Vol 110 ◽  
pp. 29-30 ◽  
Author(s):  
E. Preuss ◽  
W. Alef ◽  
N. Whyborn ◽  
P.N. Wilkinson ◽  
K.I. Kellermann
Keyword(s):  
Radio Source ◽  
Radio Sources ◽  
Radio Structure ◽  
Extragalactic Radio Sources ◽  
North East ◽  
The North ◽  
Vlbi Observations ◽  
Spectrum Radio ◽  
The One

3C147 is a compact (≲1″), steep spectrum radio source identified with a quasar at z = 0.545 (0″.001 = 7.4 pc; c/Ho = 6000 Mpc and qo = 0.5). The radio structure shown by VLBI observations at 18 cm (Readhead & Wilkinson, 1980; Simon et al., this volume), at 50 cm (Wilkinson et al., 1977), and at 90 cm (Simon et al., 1980 and 1983) shows a bright ‘core’ (60 pc at one end of a ‘jet’ ~0″.2 (1.5 kpc) in length oriented in p.a. ~ −130°. In this sense 3C147 is typical of the one-sided ‘core-jet’ structures commonly found in the centres of other extragalactic radio sources. However, MERLIN observations at 6 cm (Wilkinson, this vol.) and VLA observations at 2 cm (Crane & Kellermann, unpubl.; Readhead et al., 1980) show a larger elongated feature extending ~0″.5 (3.7 kpc) to the North East of the bright core in p.a. ~25° or on the opposite side to the 0″.2 jet.

Sign in / Sign up

Export Citation Format

Share Document