A 1.2 mm MAMBO/IRAM-30 m survey of dust emission from the highest redshift PSS quasars

¹ Institut d'Astrophysique de Paris, CNRS, 98bis boulevard Arago, 75014 Paris, France
² Institut d'Astrophysique Spatiale, Université de Paris XI, 91405 Orsay, France
³ Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
⁴ Institute of Astronomy, Madingley Road, Cambridge CB3 0HA, UK
⁵ National Radio Astronomy Observatory, PO Box O, Socorro, NM 87801, USA
⁶ Cavendish Laboratory, Madingley Road, Cambridge CB3 0HE, UK

Corresponding author: A. Omont, omont@iap.fr

Received: 11 December 2000
Accepted: 13 May 2001

Abstract

We report 250 GHz (1.2 mm) observations of redshift ≥3.8 quasars from the Palomar Sky Survey (PSS) sample, using the Max-Planck Millimetre Bolometer (MAMBO) array at the IRAM 30-metre telescope. Eighteen sources were detected and upper limits were obtained for 44 with 3σ flux density limits in the range 1.5-4 mJy. Adopting typical dust temperatures of 40-50 K, we derive dust masses of a few and far-infrared luminosities of order . We suggest that a substantial fraction of this luminosity arises from young stars, implying star formation rates approaching yr^-1 or more. The high millimetre detection rate supports current views on a connection between AGN and star forming activity, suggesting a parallel evolution of the central black hole and of the stellar core of a galaxy, although their growth-rate ratio seems higher than the mass ratio observed in nearby galaxies. The observed, exceptionally bright objects may trace the peaks of the primordial density field, the cores of future giant ellipticals.