These are the Proceedings of Symposium No. 195 of the
International Astronomical Union (IAU), held in Bozeman, Montana,
U.S.A., during 6--10 July 1999, and hosted by Montana State
University (MSU).
Recent years have seen much progress in the study of the basic
mechanisms responsible for high-energy emission from astrophysical
plasmas. From the wealth of data from observatories such as Einstein,
Exosat, Ginga, IUE, ROSAT, EUVE, GRO, ASCA, SAX, RXTE, and
Yohkoh, it
is now clear that many common physical processes are at work in different
astrophysical systems. Magnetohydrodynamic processes, for example,
play key dynamical roles in the solar corona and in accreting
B
systems in active galactic nuclei (AGN) and Galactic compact objects.
Magnetic reconnection processes, thought to be involved in the
heating of the solar corona, are expected to occur in accretion disks
and neutron star magnetospheres. The physics of emission from
highly relativistic plasmas is critical to understanding jets from
AGN, supernovae, and the relativistic fireballs now thought responsible
for cosmic gamma-ray bursts. Plasma processes were also of crucial
importance in the early universe and affected the development of
the primordial magnetic field and of structure.
Though similar physical processes are encountered by researchers
studying compact objects, accreting sources, supernovae, the Sun, and
the early universe, researchers from these different subfields
interact surprisingly little. The purpose of this symposium was
to bring together experts from different subfields of high-energy
astrophysics who encounter common questions in their research. Our
goal was to create a forum in which the participants could benefit
from the expertise of others who have worked on similar problems
in different astrophysical contexts.
With the successful
launch of the Chandra Observatory and XMM, and the launch
of HESSI imminent, this conference formed an ideal
environment in which to discuss these exciting problems.
The meeting focused on high-energy processes taking place in
astrophysical plasmas, and included discussion of the mechanisms
of high-energy emission from various magnetized and thermal
plasmas. Particular emphasis was given to accreting systems,
jets, neutron stars, black holes, the Sun, supernovae, gamma-ray
bursts, soft gamma repeaters, and the early universe.
Both theoretical and observational issues were covered, and
future directions discussed.
The symposium started with reviews on past, current, and future
satellite observations in high-energy and solar astrophysics,
followed by theoretical papers which were more directly related to
these observations, on high-energy phenomena in, and emission from,
astrophysical plasmas. The meeting proceeded to
cover more theory-oriented, basic physical problems, such as
the effects of magnetic fields, particle acceleration,
and physical processes in relativistic astrophysical plasmas.
The afternoon of the last day was reserved for a panel discussion
and conference summary. This symposium included invited review
and specialty papers, a panel discussion, a conference summary,
and contributed papers (mostly posters but some oral). Here,
we present these papers.
The spirit of the meeting was to bring together researchers
from different subfields of high-energy astrophysics to share their
expertise in studying emission processes of common interest in
astrophysical plasmas. It was also to bring together
observers and theorists for mutual interaction. In this sense,
this symposium was to be unique in its scope and emphasis.
As C.R. Canizares emphasized in the panel discussion,
this symposium succeeded, at least to a certain degree, in
accomplishing this ambitious though difficult goal, and we
hope that this will be the beginning of more such meetings
in the future.
Acknowledgments.
The Scientific Organizing Committee consisted of
Drs. G. Ai, R. Blandford, T. Courvoisier, L. Culhane (Co-chair),
G.G. Fazio, K. Nomoto, A. Nordlund, F. Pacini, M.J. Rees,
R. Romani, G. Srinivasan, J. Trumper, S. Tsuruta (Co-chair),
and L. Woltjer. We express deep gratitude to these
colleagues and others, such as L. Acton, R. Canfield,
A. Fabian, A. Gruzinov, D. Longcope, and W. Wamsteker,
for very useful suggestions and input towards making
the program of the meeting scientifically more interesting.
The Local Organizing Committee consisted of L. Acton (Co-chair),
R. Canfield, W. Hiscock, M. Larson, B. Link, D. Longcope,
S. Tsuruta (Co-chair), and M. Wills-Davey. J. Halvorson (Director),
A. Fox, and other members of MSU Conference Services
delt with practical matters. We are grateful to these
colleagues for their efficient efforts in organizing the
meeting, together with the assistance of junior staff and
graduate students A. Burnette, A. Davey, K. Fukumura, C. Kankelborg,
A. LeRoux, D. McKenzie, E. Noonan, D. Rilett, M. Teter, and B. Welsch.
Finally, we acknowledge with deep gratitude the sponsorship
of the meeting by IAU, and the financial support from IAU,
MSU, NASA, and NSF. The support
helped us not only successfully organize the meeting but also
assist in the attendance of some key speakers and active,
young research workers.
Bozeman, MT, U.S.A. | Piet Martens, Sachiko Tsuruta, and Mark Weber |
February 2000 |