HERSCHEL—PACS Bolometer Arrays for Submillimeter Ground-Based Telescopes

Abstract

The Herschel Space Observatory will carry onboard a new kind of bolometric architecture for the PACS (Photodetector Array Camera and Spectrometer) submillimeter photometer. These new generation CCD-like multiplexed bolometer arrays are buttable and enable the conception of large fully sampled focal planes either for space or for ground-based telescopes. We present here some development for ground-based applications in the context of the ARTEMIS (ARchitecture de bolometres pour des TElescopes sub-MIllimetriques au Sol) project. We have developed an electro-thermal numerical model that simulates the performances of these semiconducting bolometers under specific ground-based conditions (different wavelengths and background powers for example). This model permits to determine the optimal parameters for each condition and shows that the bolometers can be background limited in each atmospheric transmission window between 200 and 450 microns. We also describe the optical system that provides a high optical efficiency in each submillimeter atmospheric window. Astronomical observations made with a prototype on the APEX telescope are presented.