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Aims. We investigate the radio loudness ($\mathcal{R}$) distribution in a large, homogeneous sample of radio galaxies. Methods. The sample is composed of galaxies from the ROGUE I/II catalogue belonging to the SDSS MGS and is divided into…

Astrophysics of Galaxies · Physics 2026-04-01 A. Wójtowicz , N. Vale Asari , Ł. Stawarz , G. Stasinska , D. Kozieł-Wierzbowska

We present deep {\it Spitzer} mid-infrared spectroscopy, along with 16, 24, 70, and 850\,$\micron$\ photometry, for 22 galaxies located in the Great Observatories Origins Deep Survey-North (GOODS-N) field. The sample spans a redshift range…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-06 E. J. Murphy , R. R. Chary , D. M. Alexander , M. Dickinson , B. Magnelli , G. Morrison , A. Pope , H. I. Teplitz

An international project is underway to design and build a radio telescope with an effective collecting area two orders of magnitude greater than the largest existing instruments. One of the many scientific goals of this instrument will be…

Astrophysics · Physics 2009-09-25 A. Hopkins , R. Windhorst , L. Cram , R. Ekers

We have analyzed the NVSS and SUMSS data at 1.4 GHz and 843 MHz for a well defined complete sample of hard X-ray AGN observed by INTEGRAL. A large number (70/79) of sources are detected in the radio band, showing a wide range of radio…

High Energy Astrophysical Phenomena · Physics 2015-06-23 F. Panessa , A. Tarchi , P. Castangia , E. Maiorano , L. Bassani , G. Bicknell , A. Bazzano , A. J. Bird , A. Malizia , P. Ubertini

In order to find more examples of the elusive high-redshift molecular absorbers, we have embarked on a systematic discovery program for highly obscured, radio-loud "invisible AGN" using the VLA Faint Images of the Radio Sky at Twenty…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 T. Yan , J. T. Stocke , J. Darling , F. Hearty

We have made the first detailed study of the high-frequency radio-source population in the local universe, using a sample of 202 radio sources from the Australia Telescope 20 GHz (AT20G) survey identified with galaxies from the 6dF Galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Elaine M. Sadler , Ronald D. Ekers , Elizabeth Mahony , Tom Mauch , Tara Murphy

We present a low-frequency imaging study of an extended sample of X-shaped radio sources using the Giant Metrewave radio telescope (GMRT) at two frequencies (610 and 240 MHz). The sources were drawn from a Very Large Array FIRST-selected…

Astrophysics of Galaxies · Physics 2019-05-08 Dharam V. Lal , Biny Sebastian , C. C. Cheung , A. Pramesh Rao

I describe an observational program aimed at understanding the radio emission from distant, rapidly evolving galaxy populations. These observations were carried out at 1.4 and 8.5 GHz with the VLA centered on the Hubble Deep Field. Further…

Astrophysics · Physics 2009-10-31 E. A. Richards

Many sources in the fourth INTEGRAL/IBIS catalogue are still unidentified, since they lack an optical counterpart. An important tool that can help in identifying/classifying these sources is the cross-correlation with radio catalogues,…

High Energy Astrophysical Phenomena · Physics 2015-06-11 Manuela Molina , Raffaella Landi , Loredana Bassani , Angela Malizia , John B. Stephen , Angela Bazzano , Antony J. Bird , Neil Gehrels

Most of the radio-loud narrow-line Seyfert 1 (NLS1) galaxies resemble compact steep-spectrum sources. However, the extremely radio-loud ones show blazar-like characteristics, like flat radio spectra, compact radio cores, substantial…

Astrophysics of Galaxies · Physics 2018-07-18 K. É. Gabányi , A. Moór , S. Frey

We investigate faint radio emission from low- to high-luminosity Active Galactic Nuclei (AGN) selected from the Sloan Digital Sky Survey (SDSS). Their radio properties are inferred by co-adding large ensembles of radio image cut-outs from…

Astrophysics · Physics 2008-11-26 W. H. de Vries , J. A. Hodge , R. H. Becker , R. L. White , D. J. Helfand

This is the first of two papers in which a study is made of a sample of 12 southern radio-luminous Seyfert galaxies. Our aim is to investigate possible correlations between radio morphology and nuclear/circumnuclear emission-line…

Astrophysics · Physics 2009-10-30 M. A. Bransford , P. N. Appleton , C. A. Heisler , R. P. Norris , A. P. Marston

We investigate the high-frequency radio spectra of twenty low-luminosity active galactic nuclei (LLAGNs) with compact radio cores. Our millimetre survey with the Nobeyama Millimetre Array (NMA) and analyses of submillimetre archival data…

Astrophysics · Physics 2009-11-13 A. Doi , S. Kameno , K. Kohno , K. Nakanishi , M. Inoue

We present radio spectra spanning $0.1 - 10$ GHz for the sample of heavily obscured luminous quasars with extremely red mid-infrared-optical colors and compact radio emission. The spectra are constructed from targeted 10 GHz observations…

The results of Chandra snapshot observations of 11 LINERs (Low-Ionization Nuclear Emission-line Regions), three low-luminosity Seyfert galaxies, and one HII-LINER transition object are presented. Our sample consists of all the objects with…

Astrophysics · Physics 2010-04-06 Yuichi Terashima , Andrew S. Wilson

We present results from the Very Long Baseline Array (VLBA) multi-frequency (1.6, 4.4, 8.6, 22 GHz), high-sensitivity (~25 microJy beam^-1), sub-parsec scale (<1 pc) observations and Spectral Energy Distributions (SEDs) for a sample of 12…

We present spectra and near-infrared images of a sample of faint radio sources initially selected as promising high-redshift radio galaxy (HzRG) candidates. We have determined redshifts for a total of 13 radio galaxies with redshifts…

Low-frequency radio surveys allow in-depth studies and new analyses of classes of sources previously known and characterised only in other bands. In recent years, low radio frequency observations of blazars have been available thanks to new…

Astrophysics of Galaxies · Physics 2020-01-08 Daniele d'Antonio , Marcello Giroletti , Gabriele Giovannini , Alessandro Maini

In order to analyze the importance of the star formation rate in generating and amplifying magnetic fields in the interstellar medium we obtained deep total power and polarization maps at 4.85 GHz of three late type spiral galaxies NGC4236,…

Astrophysics · Physics 2009-11-11 K. T. Chyzy , D. J. Bomans , M. Krause , R. Beck , M. Soida , M. Urbanik

Many of the powerful radio galaxies observed at high redshift are very small, presumably because they are very young. A simple model, which treats the radio source as a bubble expanding into a radially stratified medium, is capable of…

Astrophysics · Physics 2007-05-23 Mitchell C. Begelman