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Related papers: The extragalactic radio-source population at 95 GH…

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We have used VLBA fringe visibility data obtained at 15 GHz to examine the compact structure in 250 extragalactic radio sources. For 171 sources in our sample, more than half of the total flux density seen by the VLBA remains unresolved on…

We present a short overview on the extragalactic background radiation from radio to X-rays, with an eye to the relation to galaxy formation and emphasizing on astrophysical backgrounds (as opposed to cosmological). As the radio background,…

Astrophysics · Physics 2007-05-23 G. De Zotti , A. Franceschini , L. Toffolatti , P. Mazzei , L. Danese

We present detailed predictions of the contributions of the various source populations to the counts at frequencies of tens of GHz. New evolutionary models are worked out for flat-spectrum radio quasars, BL Lac objects, and steep-spectrum…

Star forming galaxies are thought to dominate the sub-mJy radio population, but recent work has shown that low luminosity AGN can still make a significant contribution to the faint radio source population. Spectral indices are an important…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 M. T. Huynh , A. M. Hopkins , E. Lenc , M. Y. Mao , E. Middelberg , R. P. Norris , K. E. Randall

The radio spectral index is a powerful probe for classifying cosmic radio sources and understanding the origin of the radio emission. Combining data at 147 MHz and 1.4 GHz from the TIFR GMRT Sky Survey (TGSS) and the NRAO VLA Sky Survey…

Instrumentation and Methods for Astrophysics · Physics 2018-01-10 F. de Gasperin , H. T. Intema , D. A. Frail

We review the statistical properties of the main populations of radio sources, as emerging from radio and millimeter sky surveys. Recent determinations of local luminosity functions are presented and compared with earlier estimates still in…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Gianfranco De Zotti , Marcella Massardi , Mattia Negrello , Jasper Wall

We separate the extragalactic radio source population above ~50 uJy into active galactic nuclei (AGN) and star-forming sources. The primary method of our approach is to fit the infrared spectral energy distributions (SEDs), constructed…

We have identified 7824 radio sources from the 1.4GHz NRAO VLA Sky Survey (NVSS) with galaxies brighter than K=12.75 mag. in the Second Incremental Data Release of the 6dF Galaxy Survey (6dFGS DR2). The resulting sample of redshifts and…

Astrophysics · Physics 2008-11-26 Tom Mauch , Elaine M. Sadler

We present a method to simulate the polarization properties of extragalactic radio sources at microwave frequencies. Polarization measurements of nearly 2x10^6 sources at 1.4 GHz are provided by the NVSS survey. Using this catalogue and the…

Astrophysics · Physics 2008-11-26 M. Tucci , E. Martinez-Gonzalez , L. Toffolatti , J. Gonzalez-Nuevo , G. De Zotti

We investigate the radio properties of a complete sample of nearby, massive, X-ray bright elliptical and S0 galaxies. Our sample contains 18 galaxies with ROSAT All-Sky Survey X-ray fluxes Fx_(0.1-2.4 keV) > 3 x 10^(-12) erg/s/cm^2, within…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Robert Dunn , Steve Allen , Greg Taylor , Kathleen Shurkin , Gianfranco Gentile , Andy Fabian , Chris Reynolds

Compact Steep Spectrum (CSS) and Gigahertz Peaked Spectrum (GPS) sources are classes of compact, powerful, extragalactic objects. These sources are thought to be the earliest stages in the evolution of radio galaxies, capturing the ignition…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Kate E. Randall , Andrew M. Hopkins , Ray P. Norris , Philip G. Edwards

Radio surveys with the Australia Telescope Compact Array have been carried out at 1.4 and 2.4 GHz with a limiting flux of 0.2 mJy at each frequency in the Marano Field, in which deep optical and X-ray (ROSAT) data are also available. In…

To explore the high frequency radio spectra of galaxies in clusters, we used NRAO's Very Large Array at four frequencies, 4.9-43 GHz, to observe 139 galaxies in low redshift (z<0.25), X-ray detected, clusters. The clusters were selected…

We present the results of a deep 610 MHz survey of the 1^H XMM/Chandra survey area with the GMRT. The resulting maps have a resolution of ~7 arcsec and an rms noise limit of 60 microJy. To a 5 sigma detection limit of 300 microJy we detect…

Astrophysics · Physics 2007-05-23 D. Moss , N. Seymour , I. M. McHardy , T. Dwelly , M. J. Page , N. S. Loaring

We present a new broadband radio frequency catalogue across 0.12 GHz $\le \nu \le$ 20 GHz created by combining data from the Murchison Widefield Array Commissioning Survey, the Australia Telescope 20 Gigahertz survey, and the literature.…

Astrophysics of Galaxies · Physics 2018-02-27 V. M. Harvey , T. Franzen , J. Morgan , N. Seymour

We present 1.4 and 2.5 GHz Australia Telescope Compact Array (ATCA) observations of the galaxy cluster A3158 (z=0.0597) which is located within the central part of the Horologium-Reticulum Supercluster (HRS). Spectroscopic data for the…

Astrophysics · Physics 2009-11-13 M. Johnston-Hollitt , M. Sato , J. A. Gill , M. C. Fleenor , A. -M. Brick

Using a recently completed survey of faint (sub-mJy) radio sources, selected at 1.4 GHz, a dust-free estimate of the local star formation rate (SFR) is carried out. The sample is 50% complete to 0.2 mJy, with over 50% of the radio sources…

Astrophysics · Physics 2009-10-31 B. Mobasher , L. Cram , A. Georgakakis , A. Hopkins

We present a sample of 373 peaked-spectrum (PS) sources with spectral peaks around 150MHz, selected using a subset of two LOFAR all-sky surveys, the LOFAR Two Meter Sky Survey and the LOFAR LBA Sky Survey. These surveys are the most…

We discuss our current understanding of the nature of the faint, high-frequency radio sky. The Tenth Cambridge (10C) survey at 15.7 GHz is the deepest high-frequency radio survey to date, covering 12 square degrees to a completeness limit…

Astrophysics of Galaxies · Physics 2016-03-01 Imogen H. Whittam , Julia M. Riley , David A. Green , Matt J. Jarvis

The fields chosen for the first observations of the cosmic microwave background with the Very Small Array have been surveyed with the Ryle Telescope at 15 GHz. We have covered three regions around RA 00h20m Dec +30deg, RA 09h40m Dec +32deg…