Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

A model for the cosmological evolution of low-frequency radio sources

Massardi, Marcella, Bonaldi, Anna, Negrello, Mattia ORCID:, Ricciardi, Sara, Raccanelli, Alvise and De Zotti, Gianfranco 2010. A model for the cosmological evolution of low-frequency radio sources. Monthly Notices of the Royal Astronomical Society , pp. 532-544. 10.1111/j.1365-2966.2010.16305.x

Full text not available from this repository.


We present a new evolutionary model that describes the population properties of radio sources at frequencies ≲5 GHz, thus complementing the De Zotti et al. model, holding at higher frequencies. We find that simple analytic luminosity evolution is still sufficient to fit the wealth of available data on local luminosity functions, multifrequency source counts and redshift distributions. However, the fit requires a luminosity-dependent decline of source luminosities at high redshifts, at least for steep-spectrum sources, thus confirming earlier indications of a ‘downsizing’ also for radio sources. The upturn of source counts at sub-mJy levels is accounted for by a straightforward extrapolation, using the empirical far-infrared (far-IR)/radio correlation, of evolutionary models matching the far-IR counts and redshift distributions of star-forming galaxies. We also discuss the implications of the new model for the interpretation of data on large-scale clustering of radio sources and on the integrated Sachs–Wolfe (ISW) effect, and for the investigation of the contribution of discrete sources to the extragalactic background. As for the ISW effect, a new analysis, exploiting a very clean cosmic microwave background map, yields at a substantially higher significance than reported before.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Physics and Astronomy
Subjects: Q Science > QC Physics
Uncontrolled Keywords: galaxies: active; galaxies: evolution; radio continuum: general
Publisher: Oxford University Press
ISSN: 00358711
Date of Acceptance: 7 January 2010
Last Modified: 31 Oct 2022 10:11

Citation Data

Cited 83 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item Edit Item