DFG Priority Program 1573
Physics of the Interstellar Medium
Interstellar space is filled with a dilute mixture of charged particles, atoms, molecules and dust grains,
called the interstellar medium (ISM). The average particle density of the ISM is 1 cm-3
which represents
a density lower than can be created on Earth. The ISM therefore represents a fascinating laboratory to
study the physics of highly attenuated gases, chemical processes and atomic, molecular and solid state
physics under extreme conditions and numerous other questions of natural sciences. The physics of the
ISM plays a crucial role in many areas of astronomy. Galaxy formation and evolution, the formation of stars,
cosmic nucleosynthesis, the origin of large complex, prebiotic molecules and the abundance, structure and
growth of dust grains which constitute the fundamental building blocks of planets, all these processes are
intimately coupled to the physics of the ISM. However, despite its importance, its structure and evolution is
still poorly understood.
The situation is however improving rapidly. New observations with powerful telescopes have revealed
that the ISM is a turbulent, multiphase gas, filled with structures on all resolvable spatial scales. This has
lead to a paradigm shift in our understanding of the ISM, where the old equilibrium model is being replaced
by a highly dynamical picture of strongly coupled, interacting and turbulently mixed gas phases that are far
from equilibrium and that are continuously stirred by processes that are not well understood. This insight
has attracted enormous interest in the astronomical community. We enter an era where for the first time
enough information is available to gain a deep and comprehensive physical understanding of the ISM and
the dynamical processes that govern its evolution. This is of importance for many fields in astronomy.
Main aims of this priority program:
- combine the expertise of researchers in Germany who work on different aspects of ISM physics
- investigate observationally and theoretically how various physical processes interact with one another and shape the ISM
- construct a new model of the dynamical, non-linear, multi-phase ISM
To reach this ambitious scientific goal, the SPP 1573 relies on three complementary pillars:
- Laboratory studies will provide the necessary data of molecular and ionic reactions as well as transition frequencies and data on dust physics, which is required for the physical and chemical description of the ISM.
- Observations are the key to constrain theoretical models and give insight into the structure of the ISM and its dependence on galactic environment.
- Theory and numerical simulations will shed light on physical processes and the importance of their combined effect on structuring the ISM and the driving of turbulence.
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For further information we refer to the (shortened) original proposal to establish the priority program 1573. |
