With the last Newsletter of the year 2001, we reach two round numbers: the 50th edition of the Letter, and ten years of its publication, as the very first Letter was published on January 1, 1992.
It contained the call for proposals on the IRAM instruments; the three-antenna PdBI had just completed its first year of operation at 3mm wavelengths. The 30m was reporting on holography and VLBI results, and already offering remote observing with single-beam receivers at 3, 2, 1.3 and 0.8 mm.
Scientific abstracts discussed SiO emission from evolved stars and HCN in the center of other galaxies, and oxygen isotopic ratios in circumstellar envelopes.
Since then, science with the PdBI and the 30m telescope has built on the early results. Deeper images were obtained and imaging was extended as the technology advanced.
The receiver temperatures have decreased since then by a factor of about three, tuning ranges and bandwidths have increased, and new instruments like the multichannel bolometer (MAMBO) and SIS receiver (HERA) have become available at the 30m. The Plateau de Bure has increased its number of instantaneous baselines by more than a factor of three, and will reach a factor of five relative to its old three-antenna days when antenna 6 becomes operational in the next few months. Baseline tracks have been extended and the resolving power improved, and simultaneous observations at 1mm and 3mm are standard.
Over the numerous issues of the Letter, three editors have taken on the task to compile the various IRAM news items for you: Robert Lucas, Michel Guélin and finally myself. The news have covered moments of great happiness when milestones have been reached in scientific discoveries or new technical developments and moments of extreme sadness when the PdBI was struck by terrible accidents. We thank our readers and user community who have stayed with us in both extremes and the calmer waters in between, and whose interest is essential for the future of the two IRAM observatories.
Both instruments on Pico Veleta and Plateau de Bure are still being extended and improved, so that the variety of feasible science is still increasing. The Newsletter will keep you informed on new developments at the observatories.
Please remember that the ``Scientific Results'' column of the Newsletter is meant to improve the visibility of the results you have obtained with the IRAM instruments. Just send a copy of the paper title, authors, affiliation, the abstract, and the journal where the paper has been accepted or printed since the previous Newsletter to pub@iram.fr.