Astronomical Infrared Spectroscopy

Two specialized new instruments for ESO's VLT, VISIR and CRIRES, spawned the idea for this workshop. CRIRES is a dedicated very high resolution infrared spectrograph; VISIR features a high resolution spectroscopic mode. Together, the instruments combine the sensitivity of an 8m-telescope with the now well-established reliability of VLT-facility instruments. High resolution here means that lines in cool stellar atmospheres and HII-regions can be resolved. The astrophysical topics discussed in this rather specialized workshop range from the inner solar system to active galactic nuclei. There are many possibilities for new discoveries with these instruments, but the unique capability, which becomes available through high-resolution infrared spectroscopy, is the observation of molecular rotational-vibrational transitions in many astrophysical environments. Particularly interesting and surprising in this context, many papers on modeling and laboratory spectroscopy at the workshop appear to indicate that astronomical observations are lagging a bit behind in this field. The papers are an interesting mix of reports from existing high resolution facilities, reports on modeling efforts of synthetic spectra and reports on laboratory spectra. In this sense, a fruitful exchange between molecular physics and astronomy was again accomplished and is documented in this volume.

A clear and concise practical handbook on all aspects of infrared astronomy, for graduate students, researchers and keen amateurs.

The last major conference on infrared astronomy was the IAU Symposium No. 96 in June 1980. Since then, the discipline has continued to mature and to contribute to all branches of astrophysics. One particular area of growth has been in spectroscopic capabilities at all infrared wavelengths. The purpose of the Symposium in Toledo was to review the scientific questions to be addressed via infrared spectroscopy and to provide, in the proceedings, a useful summary of the field. The sensitivity of infrared spectroscopic observations is still generally limited by detector characteristics or by thermal background radiation. However in recent years improvements in detector technology together with developments in spectroscopic instrumentation have made possible both quite detailed spectroscopy of the brighter members of many classes of galactic sources and also begun to open up some infrared spectroscopy of extragalactic sources. The potential of the field in the next decade or two is clear. The lRAS mission has completed one of the pre-requisites, namely an all-sky photometric survey. Major space missions utilising cryogenic infrared telescopes have been approved in Europe (ISO) and seem likely in the USA (SIRTF); plans for space submillimeter telescopes are firming up. On the ground large telescopes optimized for infrared observations are now in operation at high altitude sites and specialized submillimeter facilities are under construction. The particular advantages of planned, very large telescopes for infrared observations are widely accepted.

The first edition of this text was written primarily by one of the present authors (HAS), with a chapter on instrumentation contributed by a second (NLA). The volume was well received, and to keep the text up-to-date a second edition was planned. For this second edition, a third author (WEK) was invited, whose background complemented that of the other two. Each of the authors was assigned several chapters as his primary task while the complete manuscript remained the second ary responsibility of all three. It is hoped that this approach has resulted in a work that is even more thorough than the first edition in covering the basic concepts of infrared spectroscopy. NELSON L. ALPERT WILLIAM E. KEISER HERMAN A. SZYMANSKI v PREFACE TO THE FIRST EDITION My experience with the many infrared spectroscopy institutes held at Canisius College and many discussions with both beginners and experienced practitioners in infrared spectroscopy have convinced me that there is a need for an introductory text devoted entirely to infrared spectroscopy, a text which can be utilized even by those who approach this study with only a limited background. This volume sprang from that conviction. It is intended for all who wish to use infrared spec troscopy in research - especially chemists doing structural work - in routine control work, in industrial development, or in medical appli cations or those military applications where it is employed as an analytical tool.

Infrared Astronomy with ISO