|
Showing 1 - 5 of
5 matches in All Departments
The most luminous compact objects are powered by accretion of mass.
Accretion disks are the one common and fundamental element of these
sources on widely different scales, ranging from close stellar
binaries, galactic black holes and X-ray pulsars to active galactic
nuclei (AGN). Key new developments in theory and observations,
reviewed by experts in the field, are presented in this book. The
contributions to the workshop cover the puzzles presented by the
X-UV spectra of AGN and their variability, the recent numerical
simulations of magnetic fields in disks, the remarkable behavior of
the superluminal source 1915+105 and the "bursting pulsar" 1744-28,
to mention a few of the topics.
Accretion disks in astrophysics represent the characteristic flow
by which compact bodies accrete mass from their environment. Their
intrinsically high luminosity, and recent progress in observational
accessibility at all wavelength bands, have led to rapidly growing
awareness of their importance and made them the object of intense
research on widely different scales, ranging from binary stars to
young stellar objects and active galactic nuclei. This book
contains the proceedings of the NATO Advanced Workshop on `Theory
of Accretion Disks 2' for which some of the most active researchers
in the different fields came together at the Max-Planck-Institut
for Astrophysics in Garching in March, 1993. Its reviews and
contributions give an up-to-date account of the present status of
our understanding and provide a stimulating challenge in
discussions of open questions in a rapidly developing field.
With the advent of space observatories and modern developments in
ground based astronomy and concurrent progress in the theoretical
understanding of these observations it has become clear that
accretion of material on to compact objects is an ubiquitous
mechanism powering very diverse astrophysical sources ranging in
size and luminosity by many orders of magnitude. A problem common
to these systems is that the material accreted must in general get
rid of its angular momentum and this leads to the formation of an
Accretion Disk which allows angular momentum re-distribution and
converts potential energy into radiation with an efficiency which
can be higher than the nuclear burning yield. These systems range
in size from quasars and active galactic nuclei to accretion disks
around forming stars and the early solar system and to compact
binaries such as cataclysmic variables and low-mass X-ray binaries.
Other objects that should be mentioned in this context are 88433,
the black hole binary candidates, and possibly gamma-ray burst
sources. Observations of these systems have provided important
constraints for theoretical accretion disk models on widely
differing scales, lumi nosities, mass-transfer rates and physical
environments."
In May 1986 a two-day workshop on Physical Processes in Comets,
Stars and Active Galaxies was held at the Ringberg Castle near Lake
Tegernsee, and this rather unusml. l collection of topics needs a
few words of explanation. When we first thought of organizing a
workshop on such a large variety of astrophysical objects our main
motivation was to honor Rudolf Kippenhahn and Hermann Ulrich
Schmidt on the occasion of their 60th birthdays, and we planned to
cover at least a fraction of their fields of active research. We
then realized immediately that despite the fact that the objects
are so different, the physical processes involved are very much the
same, and that it is this aspect of astrophysics which governed the
scientific lives of both of our distinguished colleagues and
friends and allowed them to make major contributions to all those
fields. Apparently this viewpoint was shared by many colleagues and
it was therefore not surprising that in response to our invitation
everybody who had been invited agreed to come and to present a
talk. The workshop then turned out to be a real success. In
contrast to highly specialized conferences, fundamental problems as
well as very recent devel opments were discussed and the
participants appreciated the opportunity to exchange ideas."
Accretion disks in astrophysics represent the characteristic flow
by which compact bodies accrete mass from their environment. Their
intrinsically high luminosity, and recent progress in observational
accessibility at all wavelength bands, have led to rapidly growing
awareness of their importance and made them the object of intense
research on widely different scales, ranging from binary stars to
young stellar objects and active galactic nuclei. This book
contains the proceedings of the NATO Advanced Workshop on Theory of
Accretion Disks 2' for which some of the most active researchers in
the different fields came together at the Max-Planck-Institut for
Astrophysics in Garching in March, 1993. Its reviews and
contributions give an up-to-date account of the present status of
our understanding and provide a stimulating challenge in
discussions of open questions in a rapidly developing field.
|
|