Speaker
Ralf Klessen
(Heidelberg University, Center for Astronomy)
Description
Stars and star clusters are the fundamental visible building blocks of galaxies at
present days as well as in the early universe. They form by gravitational collapse in
regions of high density in the complex multi-phase interstellar medium (ISM). The
process of stellar birth is controlled by the intricate interplay between the
self-gravity of the star-forming gas and various opposing agents, such as supersonic
turbulence, magnetic fields, radiation pressure, and gas pressure. Turbulence plays a
dual role. On global scales it provides support, while at the same time it can
promote local collapse. This process is modified by the thermodynamic response of the
gas, which is determined by the balance between various heating and cooling
processes, which in turn depend on the chemical composition of the material. Feedback
is essential. The momentum and energy input from stars (via outflows, winds and
supernovae) is an important driver of ISM turbulence, similar
holds for stellar radiation which influences the thermal and chemical make-up of the
ISM. I will review the current status of the field and discuss a few examples of
recent progress.
Primary author
Ralf Klessen
(Heidelberg University, Center for Astronomy)
