Workshop on Interstellar
To be held at the
Lorentz Center, April17-20, 2001
One of the
biggest surprises of the ISO mission was the widespread presence of crystalline
silicates in the universe. Previous studies – largely limited to the atmospheric
windows at 10 and 20 mm –
revealed scant evidence for crystalline silicate components in space and then
mainly in solar systems objects such as comets and interplanetary dust
particles. ISO / SWS has revealed the presence of crystalline silicates in
Herbig AeBe stars, Asymptotic Giant Branch stars, planetary nebulae, and
Luminous Blue Variables. In contrast there is little evidence for the presence
of crystalline silicates in the interstellar medium. The spectrum of
crystalline silicates is very characteristic for the detailed properties
(cation; temperature; structure;…) of the material present and hence these
observations provide a new and exciting tool
for the study of interstellar dust.
It is clear that we are at an
exciting junction where infrared spectroscopy of a variety of objects, in
combination with detailed laboratory and theoretical studies, can be expected to lead to significant
advances in our understanding of the origin and evolution of interstellar
silicates. It is very timely therefore to organize a small informal workshop in
order to bring together scientists working in the area of infrared observations
of interstellar and circumstellar silicates, observational studies of solar
system objects, laboratory characterization of silicate (and other oxide)
materials, laboratory studies of solar system materials (meteorites, IDPs) and
theorists involved in modeling interstellar dust in these environments to focus
on the composition and evolution of interstellar silicates.
major aim of this workshop will be to summarize the current knowledge gained
from ISO and to confront this with experimental and theoretical studies of the
processes important for the origin and evolution of interstellar silicates.
Besides cataloging our current knowledge, our aim is also to chart the future.
In particular, new exciting observational opportunities arise on the horizon.
SIRTF will be launched mid 2002 and SOFIA
will come on line in 2003, providing us with further spectroscopic views
of interstellar silicates. The VLT and Gemini will soon be equipped with
state-of-the-art instrumentation in the 10 mm window. On a somewhat longer timescale, by the end of
the decade, a mid-infrared spectrometer on NGST may become available.
Topics to be discussed at this meeting
Observations of interstellar and circumstellar silicates
Laboratory spectroscopy of silicates and other oxide
The physics of the crystalline-amorphous transition
The origin and evolution of circumstellar and interstellar
The relationship between circumstellar, interstellar and
solar system silicates.
meeting will be held at the Lorentz Center at the Rijksuniversiteit Leiden the
week of April 17th, 2001 [ to accommodate European customs, starting
the Tuesday after Eastern]. The meeting will be highly informal with ample time
for informal discussions. Each of the attendees will be provided with a
workspace in the Lorentz Center with a PC or X-terminal. In this way we hope to
provide a stimulating working atmosphere which will bevery conductive to start
up new collaborative projects among the attendees. In line with the informal
character and to keep up the pressure on the attendees to the minimum, no
written proceedings will appear.