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Start Over Subject radio galaxies Validation Level 2
511. "X-shaped" radio sources. II. Sample properties
ID:
ivo://CDS.VizieR/J/ApJ/852/48
Title:
"X-shaped" radio sources. II. Sample properties
Short Name:
J/ApJ/852/48
Date:
21 Oct 2021
Publisher:
CDS
Description:
In an earlier paper, we presented Jansky Very Large Array multi-frequency, multi-array continuum imaging of a unique sample of low-axial ratio radio galaxies. In this paper, the second in the series, we examine the images to learn the phenomenology of how the off-axis emission relates to the main radio source. Inversion-symmetric offset emission appears to be bimodal and to originate from one of two strategic locations: outer ends of radio lobes (outer-deviation) or from inner ends (inner-deviation). The latter sources are almost always associated with edge-brightened sources. With S- and Z-shaped sources being a subset of outer-deviation sources, this class lends itself naturally to explanations involving black hole axis precession. Our data allow us to present a plausible model for the more enigmatic inner-deviation sources with impressive wings; as for outer-deviation sources these too require black hole axis shifts, although they also require plasma backflows into relic channels. Evolution in morphology over time relates the variety in structures in inner-deviation sources including XRGs. With features such as non- collinearities, central inner-S "spine," corresponding lobe emission peaks, double and protruding hotspots not uncommon, black hole axis precession, drifts, or flips could be active in a significant fraction of radio sources with prominent off-axis emission. At least 4% of radio galaxies appear to undergo black hole axis rotation. Quasars offer a key signature for recognizing rotating axes. With a rich haul of sources that have likely undergone axis rotation, our work shows the usefulness of low-axial ratio sources in pursuing searches for binary supermassive black holes.
512. "X-shaped" radio sources. I. VLA imaging
ID:
ivo://CDS.VizieR/J/ApJ/852/47
Title:
"X-shaped" radio sources. I. VLA imaging
Short Name:
J/ApJ/852/47
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present archival and Jansky Very Large Array multi-frequency multi-array radio continuum imaging of a unique sample of 100 radio sources that have been selected to be candidate "X-shaped" radio galaxies (XRGs). The archival data were calibrated in AIPS (Bridle & Greisen 1994, NRAO AIPS Memo 87) and imaged using DIFMAP (Shepherd+ 1994BAAS...26..987S), while the new Very Large Array data were calibrated and imaged in CASA (McMullin+ 2007ASPC..376..127M). No attempt was made to re-image the archival data in CASA. Altogether we present images of 95 of the 100 sources. These observations give us the opportunity to study radio sources with synchrotron plasma that is significantly offset from the main radio axis and therefore to open a window into investigations of physical mechanisms responsible for depositing the plasma in off-axis regions. Here, we present the technical details of the observations and all of the total intensity images, while in subsequent papers we use them to examine critically various models for the formation of XRGs. Spectral index and linear polarization information is also presented and analyzed in further papers in this series.
513. XXL Survey. DR2
ID:
ivo://CDS.VizieR/IX/52
Title:
XXL Survey. DR2
Short Name:
IX/52
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the second data release (DR2) of the XXL Survey, contextually with the appearance of a second A&A special issue dedicated to XXL. This intermediate release includes the following catalogues and data: The X-ray point source catalogue (3XLSS) and the associated multiwavelength catalogues in the XXL-N and XXL-s areas (XXL paper XXVII). The same paper also provides the list of XMM pointings used, and a supplementary catalogue of redshifts obtained with the AAOmega spectrograph in the XXL-S area. The XXL-365-GC galaxy cluster catalogue (XXL paper XX) with the complete subset of clusters for which the selection function is well determined plus all X-ray clusters which are, to date, spectroscopically confirmed. The ATCA 2.1 GHz radio source catalogue in the XXL-S area (XXL paper XXVIII), together with the catalogue of ther optical and near infrared counterparts (XXL paper XXVI). The GMRT 610 MHz radio source catalogue in the XXL-N area (XXL paper XXIX). FITS images of the XXL-North field: continuum radio mosaic from observations with the Giant Meterwave Radio Telescope (GMRT) at 610MHz, and the corresponding noise map. A complete spectrophotometric sample of galaxies within X-ray detected, optically spectroscopically confirmed groups and clusters (G&C), including also field objects, in the XXL-N area (XXL paper XXII). The list of brightest cluster galaxies (BCGs) in the XXL-N area (XXL paper XXVIII). FITS images of the two radio galaxies described in XXL paper XXXIV. ATCA XXL-S source classification data (XXL paper XXXVI) http://sci.esa.int/xmm-newton/60686-tracing-the-universe-x-ray-survey-\ supports-standard-cosmological-model/ List of XXL DR2 papers: XVI. The clustering of X-ray selected galaxy clusters at z~0.3 XVII. X-ray and Sunyaev-Zel'dovich properties of the redshift 2.0 galaxy cluster XLSSC 122 XVIII. ATCA 2.1 GHz radio source catalogue and source counts for the XXL-South field XIX. A realistic population of simulated X-ray AGN: Comparison of models with observations XX. The 365 cluster catalogue XXI. The environment and clustering of X-ray AGN in the XXL-South field XXII. The XXL-North spectrophotometric sample and galaxy stellar mass function in X-ray detected groups and clusters XXIII. The mass scale of XXL clusters from ensemble spectroscopy XXIV. The final detection pipeline XXV. Cosmological analysis of the C1 cluster number counts XXVI. Optical and near infrared identification of the ATCA 2.1 GHz radio sources in the XXL-S field XXVII. The 3XLSS point source catalogue XXVIII. Galaxy luminosity functions of the XXL-N clusters XXIX. GMRT 610 MHz continuum observations XXX. Characterisation of the XLSSsC N01 supercluster and analysis of the galaxy stellar populations XXXI. Classification and host galaxy properties of 2.1 GHz ATCA XXL-S radio sources XXXII. Spatial clustering of the XXL-S AGN XXXIII. Chandra constraints on the AGN contamination of z > 1 XXL galaxy clusters XXXIV. Double irony in XXL-North. A tale of two radio galaxies in a supercluster at z = 0.14 XXXV. The role of cluster mass in AGN activity XXXVI. Evolution and black hole feedback of high-excitation and low-excitation radio galaxies in XXL-S
514. z<1 3CR radio galaxies and quasars star formation
ID:
ivo://CDS.VizieR/J/AJ/151/120
Title:
z<1 3CR radio galaxies and quasars star formation
Short Name:
J/AJ/151/120
Date:
16 Dec 2021 13:37:06
Publisher:
CDS
Description:
Using the Herschel Space Observatory we have observed a representative sample of 87 powerful 3CR sources at redshift z<1. The far-infrared (FIR, 70-500 {mu}m) photometry is combined with mid-infrared (MIR) photometry from the Wide-Field Infrared Survey Explorer and cataloged data to analyze the complete spectral energy distributions (SEDs) of each object from optical to radio wavelength. To disentangle the contributions of different components, the SEDs are fitted with a set of templates to derive the luminosities of host galaxy starlight, dust torus emission powered by active galactic nuclei (AGNs), and cool dust heated by stars. The level of emission from relativistic jets is also estimated to isolate the thermal host galaxy contribution. The new data are in line with the orientation-based unification of high-excitation radio-loud AGN, in that the dust torus becomes optically thin longwards of 30 {mu}m. The low-excitation radio galaxies and the MIR-weak sources represent an MIR- and FIR-faint AGN population that is different from the high-excitation MIR-bright objects; it remains an open question whether they are at a later evolutionary state or an intrinsically different population. The derived luminosities for host starlight and dust heated by star formation are converted to stellar masses and star-formation rates (SFR). The host-normalized SFR of the bulk of the 3CR sources is low when compared to other galaxy populations at the same epoch. Estimates of the dust mass yield a 1-100 times lower dust/stellar mass ratio than for the Milky Way, which indicates that these 3CR hosts have very low levels of interstellar matter and explains the low level of star formation. Less than 10% of the 3CR sources show levels of star formation above those of the main sequence of star-forming galaxies.