This work was supported in part by the "Surveys with the Infrared Space Observatory" network set up by the European Commission under contract ERB FMRX-CT96-0068 of its TMR programme. This paper is based on observations made at the European Southern Observatory, La Silla, Chile. The Infra Red Astronomical Satellite (IRAS) was developed and operated by the Netherlands Agency for Aerospace Programs (NIVR), the U.S. National Aeronautics and Space Administration (NASA) and the U.K. Science and Engineering Council Research (SERC). The research of Van der Werf has been made possible by a fellowship of the Royal Netherlands Academy of Arts and Sciences.
© European Southern Observatory (ESO) 1999
Online publication: February 23, 1999