The extended counterpart of submm source Lockman 850.1^*

¹ Max-Planck-Institut für extraterrestrische Physik, Postfach 1312, 85741 Garching, Germany
² Institute for Astronomy, Department of Physics & Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ, UK
³ Osservatorio Astronomico di Padova, vicolo dell'Osservatorio 5, 35122 Padova, Italy
⁴ Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK
⁵ Astrophysics Group, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2BZ, UK
⁶ AIP, An der Sternwarte 16, 14482 Potsdam, Germany
⁷ Instituto Nacional de Astrofisica, Optica y Electronica (INAOE), Apartado Postal 51 y 216, 72000 Puebla, Pue., Mexico
⁸ UK ATC, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK
⁹ Astronomy Centre, University of Sussex, Falmer, Brighton BN1 9QJ, UK
¹⁰ Unit for Space Sciences and Astrophysics, University of Kent, Canterbury, Kent CT2 7NR, UK

Corresponding author: D. Lutz, lutz@mpe.mpg.de

Received: 11 June 2001
Accepted: 6 August 2001

Abstract

The IRAM Plateau de Bure mm interferometer and deep K-band imaging have been used to identify the brightest submm source detected in the Lockman field of the UK 8 mJy SCUBA survey. The near infrared counterpart is an extended (20-30 kpc), clumpy, and extremely red object. The spectral energy distribution suggests it to be a dusty star forming object at a redshift of about 3 (2-4). Its star formation rate and near-infrared properties are consistent with Lockman 850.1 being a massive elliptical in formation.