English
Related papers

Related papers: MIGHTEE: exploring the relationship between spectr…

200 papers

We present two new radio continuum images obtained with Apertif at 1.4 GHz. The images, produced with a direction-dependent calibration pipeline, cover 136 square degrees of the Lockman Hole and 24 square degrees of the ELAIS-N fields, with…

Astrophysics of Galaxies · Physics 2025-08-06 A. M. Kutkin , R. Morganti , T. A. Oosterloo , E. A. K. Adams , H. Dénes , J. van Leeuwen , M. J. Norden , E. Orru

Infrared-Faint Radio Sources (IFRSs) are an important class of high-redshift active galaxy, and potentially important as a means of discovering more high-redshift radio sources, but only 25 IFRSs had redshifts prior to this paper. Here we…

Astrophysics of Galaxies · Physics 2018-12-12 Brendan J. Orenstein , Jordan D. Collier , Ray P. Norris

We present a new catalog of high-redshift candidate \textit{Herschel} sources. Our sample is obtained after applying a multifrequency filtering method ("matched multifilter"), which is designed to improve the signal-to-noise ratio (S/N) of…

Astrophysics of Galaxies · Physics 2019-02-06 A. Manjón-García , D. Herranz , J. M. Diego , L. Bonavera , J. González-Nuevo

Context. Radio halos are megaparsec-scale diffuse radio sources{ mostly} located at the centres of merging galaxy clusters. The common mechanism invoked to explain their origin is the re-acceleration of relativistic particles caused by…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-27 G. Di Gennaro , R. J. van Weeren , R. Cassano , G. Brunetti , M. Brüggen , M. Hoeft , E. Osinga , A. Botteon , V. Cuciti , F. de Gasperin , H. J. A. Röttgering , C. Tasse

We use the K-z relation for radio galaxies to illustrate why it has proved difficult to obtain definitive cosmological results from studies based entirely on catalogues of the brightest radio sources, e.g. 3C. To improve on this situation…

The results of an optical and infrared investigation of a complete sub-sample of the Leiden-Berkeley Deep Survey (flux > 1 mJy at 1.4 GHz) are presented. Optical counterparts have been identified for 69 of the 73 sources in the two Hercules…

Astrophysics · Physics 2009-10-31 Ian Waddington

The relationship between the clustering of dark matter and that of luminous matter is often described using the bias parameter. Here, we provide a new method to probe the bias of intermediate to high-redshift radio continuum sources for…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Sean Passmoor , Catherine Cress , Andreas Faltenbacher , Russell Johnston , Mathew Smith , Ando Ratsimbazafy , Ben Hoyle

{Abridged} A combination of spectroscopy and broadband photometric redshifts has been used to find the complete redshift distribution of the Hercules sample of millijansky radio sources. These data have been used to examine the evolution of…

Astrophysics · Physics 2009-11-06 I. Waddington , J. S. Dunlop , J. A. Peacock , R. A. Windhorst

Around 10% of bright low-frequency radio sources observed with the Murchison Widefield Array (MWA) show strong Interplanetary Scintillation (IPS) on timescales of a few seconds, implying that almost all their low-frequency radio emission…

Astrophysics of Galaxies · Physics 2018-11-28 Elaine M. Sadler , Rajan Chhetri , John Morgan , Elizabeth K. Mahony , Thomas H. Jarrett , Steven Tingay

Radio observations offer a dust-independent probe of star formation and active galactic nucleus (AGN) activity, but sufficiently deep data are required to access the crossover luminosity between these processes at high redshift ($z>4.5$).…

We present evidence for a positive angular correlation between bright submillimetre sources and low-redshift galaxies. The study was conducted using 39 sources selected from 3 contiguous, flux-limited SCUBA surveys, cross-correlated with…

Astrophysics · Physics 2009-11-10 O. Almaini , J. S. Dunlop , C. J. Willott , D. M. Alexander , F. E. Bauer , C. T. Liu

We re-examine the technique of determining the redshifts of galaxies from the ratio of the submillimeter-to-radio continuum flux densities based on a recently published catalog of 850~$\mu$m sources. We derived the expected variation of…

Astrophysics · Physics 2015-06-24 T. N. Rengarajan , Tsutomu T. Takeuchi

We present models of the 1.4 GHz to 350 GHz spectral index, alpha(350/1.4), for starburst galaxies as a function of redshift. The models include a semi-analytic formulation, based on the well quantified radio-to-far infrared correlation for…

Astrophysics · Physics 2009-10-31 C. L. Carilli , Min Su Yun

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 present a model to predict the luminosity function for radio galaxies and their linear size distribution at any redshift. The model takes a black hole mass function and Eddington ratio distribution as input and tracks the evolution of…

Astrophysics of Galaxies · Physics 2017-06-28 A. Saxena , H. J. A. Röttgering , E. E. Rigby

We show that mid-infrared data from the all-sky WISE survey can be used as a robust photometric redshift indicator for powerful radio AGN, in the absence of other spectroscopic or multi-band photometric information. Our work is motivated by…

Instrumentation and Methods for Astrophysics · Physics 2017-09-27 M. Glowacki , J. R. Allison , E. M. Sadler , V. A. Moss , T. H. Jarrett

In the next few years the classification of radio sources observed by the large surveys will be a challenging problem, and spectral index is a powerful tool for addressing it. Here we present an algorithm to estimate the spectral index of…

We investigate the correlations between spectral index, jet side and extent of the radio lobes for a sample of nearby FRII radio galaxies. In Dennett-Thorpe et al. (1997) we studied a sample of quasars and found that the high surface…

Astrophysics · Physics 2009-10-31 J. Dennett-Thorpe , A. H. Bridle , R. A. Laing , P. A. G. Scheuer

A detailed understanding of how the activity of a galactic nucleus regulates the growth of its host is still missing. To understand the activity and the types of accretion of supermassive black holes in different hosts, it is essential to…

We re-analyse the subset of the Faraday rotation measures data from the NRAO VLA Sky Survey catalogue for which redshift and spectral index information is available, in order to better elucidate the relations between these observables. We…

Astrophysics of Galaxies · Physics 2016-02-25 M. S. Pshirkov , P. G. Tinyakov , F. R. Urban