E.F. van Dishoeck, Chair
Leiden Observatory
P. O. Box 9513
2300 RA Leiden
The Netherlands
The most significant development in the last three years has been the
enormous expansion and availability of atomic and molecular databases
in electronic form (CD-ROM, ftp, World-Wide-Web).
Millions of molecular lines ranging from the millimeter to the extreme
ultraviolet part of the spectrum can now be accessed on-line, and
improved software allows rapid searches through the data bases. At the
same time, the astrophysical needs for such large data bases have
increased considerably. Spectral line surveys at submillimeter
wavelengths typically contain thousands of rotational lines,
high resolution
infrared spectra from the ground and the Infrared Space Observatory
require large amounts of information on the vibrational transitions,
whereas large format CCDs in the optical and ultraviolet allow large
wavelength ranges to be scanned for electronic transitions.
The astrophysical modeling has improved to the stage that highly
accurate molecular data are essential. A well-known
example, which has been studied intensively by several groups over
the last decade, is provided by the VUV electronic transitions of CO.
For models of cool stars and brown dwarfs, information on the
weaker transitions, whose intensities are five orders of magnitude less
than those of the strongest transitions, proves to be essential.
There have been significant developments in the experimental techniques
and theoretical methods for determining molecular structure, both
of stable species, and of radicals and ions. Of particular interest
is the progress in measuring and calculating the spectra of large
molecules, including PAH's, long carbon chains and C
.
The following summary is based on contributions sent to me by U.G. Jørgenson, T. Oka, J.P. Phillips, F. Rostas, P.L. Smith, and P. Thaddeus in the summer of 1996. Other topics have been added through a literature search. This report focuses on the highlights, and concerns only molecules of astrophysical interest. No attempt has been made to provide a complete overview or list of references. For further information on a specific molecule, the bi-monthly Berkeley Newsletter continues to be a good starting point. The printed Newsletter is essentially a bibliography of articles in the current journals on molecules comprising four or fewer atoms (contact jphillips@astro.berkeley.edu or spdavis@physics.berkeley.edu).