KOSMA 3-M SUBMILLIMETER-WAVE TELESCOPE ON GORNERGRAT - INTERSTELLAR SPECTROSCOPY AND ASTROPHYSICS

The 3-m KOSMA telescope at Gornergrat (Switzerland) is dedicated to mi llimeter- and submillimeter-wave astrophysics with observations mainly of interstellar atomic and molecular lines. This includes measurement of the large-scale structure and dynamics of molecular clouds in our galaxy for a better understanding of the processes connected with star formation. The present research activity of the observatory is descri bed with a special scope on the description of the techniques and inst rumentation used. The site at Gornergrat has superb atmospheric transp arency, thus allowing operation up into the highest-frequency atmosphe ric window at around 850 GHz. We discuss the rapid development of sens itive superconductor-insulator-superconductor mixer elements, now cove ring frequencies well up into the submillimter-wave range with close t o quantum-limit detection. As frequency-analyzing devices we exclusive ly use acousto-optical spectrometers at KOSMA. Progress into the submi llimeter spectral range is complemented by the now mature technique of building radiotelescopes with sufficient surface accuracy to guarante e operation into the terahertz region (lambda = 200 mu m). A new 3-m r eflector for the KOSMA telescope with an expected surface accuracy of 10 mu m is under construction.