MAMBO 1.25 mm observations of 3CR quasars at z ~ 1.5: on the debate of the unified schemes

Free access article

Issue		A&A Volume 445, Number 1, January I 2006


Page(s)		115 - 122
Section		Extragalactic astronomy
DOI		http://dx.doi.org/10.1051/0004-6361:20054121

A&A 445, 115-122 (2006)
DOI: 10.1051/0004-6361:20054121

MAMBO 1.25 mm observations of 3CR quasars at z ~ 1.5: on the debate of the unified schemes

M. Haas¹, R. Chini¹, S. A. H. Müller¹, F. Bertoldi² and M. Albrecht³

¹ Astronomisches Institut, Ruhr-Universität Bochum (AIRUB), Universitätsstr. 150 / NA7, 44780 Bochum, Germany
e-mail: haas@astro.rub.de
² Radioastronomisches Institut, Universität Bonn, Auf dem Hügel 71, 53121 Bonn, Germany
³ Instituto de Astronomía, Universidad Católica del Norte, Avenida Angamos 0610, Antofagasta, Chile

(Received 16 December 2004 / Accepted 2 September 2005 )

Abstract
In order to explore the nature of the 850 $\mu$ m flux difference between powerful radio galaxies and steep radio-spectrum quasars at $z\sim 1.5$ reported by Willott et al. (2002), we have observed 9 sources from their sample of 11 quasars at 1.25 mm. For 7 sources the 1.25 mm fluxes are much brighter than one would expect from a purely thermal dust model fitted to the submm data, providing evidence for the synchrotron nature of the observed 1.25 mm radiation. If we extrapolate a power-law synchrotron spectrum to shorter wavelengths, then for 6 of the 9 sources also the 850 $\mu$ m fluxes are dominated by synchrotron radiation. We discuss how far the (sub)-millimetre data can be interpreted in accordance with the orientation-dependent unified schemes for powerful radio galaxies and quasars. In this case the results challenge the reported evidence for the receding torus model and for the evolutionary trend of a declining dust luminosity with increasing projected size of the radio lobes.

Key words: galaxies: fundamental parameters -- galaxies: photometry -- galaxies: quasars: general -- infrared: galaxies

SIMBAD Objects

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.