Physical Processes in the Interstellar Medium

The ISM 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. 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. 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.

Many physical processes in the ISM have been studied in isolation and under idealized conditions. It is however their nonlinear coupling that fully characterizes the structure and evolution of the multi-phase, dynamically evolving ISM. Therefore, the first funding period of the ISM-SPP (ism-spp.de) is dedicated to the investigation of the interplay between various processes in the ISM. In this conference, we aim at (i) summarizing the recent progress and isolating the open questions as well as (ii) bringing together experts from all three research pillars (laboratory studies, observations as well as theory and computations) in order to form a consistent picture of relevant physical processes in the ISM.

In this first conference in a series organised by the DFG priority program 1573 “The Physics of the Interstellar Medium” (http://www.ism-spp.de) we will concentrate on the following questions:

  • Which are the drivers of turbulence in the ISM and how does turbulence affect the morphology and the energy of the ISM on different scales?
  • What is the intrinsic structure of molecular clouds?
  • How do molecular clouds form and evolve?
  • How do interstellar dust grains and molecules form and evolve in the ISM and how do they affect physical processes in the ISM?
  • How do stars interact with and shape the multi-phase ISM?
  • How are the processes in the ISM affected by magnetic fields?
  • How are cosmic rays accelerated in the ISM, and how do cosmic rays affect interstellar structure?