Marijke Haverkorn (NRAO/UC-Berkeley)

Turbulence in the magnetized Galactic Interstellar Medium- Marijke Haverkorn colloquium

ATNF Marsfield Lecture Theatre

Abstract

Over the past decades, the paradigm describing the Galactic
Interstellar Medium (ISM) has shifted from individual `clouds' in
thermal equilibrium to a highly non-equilibrium dynamically evolving
medium where gaseous components, magnetic fields, and cosmic rays are
in continuous interaction.

Studies of this turbulent ISM help us understand physical processes
such as how and where molecular clouds form stars, the energy sources
that stir up the gas and how much turbulence contributes to the
heating of the ISM. In addition, turbulence heavily affects the
structure and strength of the Galactic magnetic field (and vice
versa), and it plays a crucial role in the propagation of cosmic rays.

I will discuss observational studies of Galactic turbulence, focusing
on the diffuse ionized gas, and what we have learnt from those. This
includes recent estimates of typical scales of fluctuations in the
interstellar gas through depolarization studies of Galactic and
extragalactic synchrotron emission, and estimates of the strength and
structure of the magnetic field. Furthermore, I will briefly introduce
several recent, ongoing and planned radio surveys of the polarized ISM
and some preliminary or expected results.