ArTeMiS: filled bolometer arrays for next generation sub-mm telescopes

Abstract

Astronomical observations at sub-millimetre wavelengths are limited either by the angular resolution of the telescope or by the sensitivity and field of view of the detector array. New generation of radio telescopes, such as the ALMA-type antennas on Chajnantor plateau in Chile, can overcome these limitations if they are equipped with large detector arrays made of thousands of sensitive bolometer pixels. Instrumentation developments undertaken at CEA and based on the all silicon technology of CEA/Leti are able to provide such large detector arrays. The ArTeMiS project consists in developing a camera for ground-based telescopes that operates in two sets of atmospheric windows at 200-450 &#956;m (channel 1) and 800-1200 &#956;m (channel 2). ArTeMiS-1 consists in grid bolometer arrays similar to those developed by CEA for the <i>Herschel</i> Space Observatory. A prototype camera operating in this first atmospheric window was installed and successfully tested in March 2006 on the KOSMA telescope at Gornergrat (Switzerland) in collaboration with the University of Cologne. ArTeMiS-2 will consist either in antenna-coupled bolometer arrays or specific mesh bolometer arrays. By the end of 2008, ArTeMiS cameras could be operated on 10m-class telescopes on the Chajnantor ALMA site, e.g., APEX, opening new scientific prospects in the study of the early phases of star formation and in cosmology, in the study of the formation of large structures in the universe. At longer term, installation of such instrumentation at Dome-C in Antarctica is also under investigation. The present status of the ArTeMiS project is detailed in this paper.