Jul 29, 2014

Blakesley Burkhart, UW Madison

"New Frontiers for Diagnosing the Turbulent Nature of the Multiphase Magnetized Interstellar Medium"

Magnetohydrodynamic (MHD) turbulence
is a critical component of the current paradigms of star formation, dynamo theory, particle transport, magnetic reconnection  and evolution of the interstellar medium (ISM).
In order to gain understanding of how MHD turbulence regulates processes in the ISM of galaxies
a confluence of numerics, observations, and theory should be used.
In this thesis I detail progress that I have made on the
connections between  theoretical, numerical, and observational understanding of MHD turbulence as it applies
to the neutral, ionized, and molecular interstellar medium.  In particular, I discuss the development
of several new techniques for studies of turbulence to be applied to observations  in order to obtain information about the turbulence cascade and the compressibility and magnetization of the fluid. These techniques are first tested on numerical simulations
by means of synthetic observations and include the bispectrum, genus statistic, probability distribution function (PDF), hierarchical structure trees (dendrograms), and extend the knowledge of the 2D power spectrum as applied to observations.  I discus the application of these techniques to 21-cm data (tracing the warm and cold neutral medium), linear polarization gradients (tracing the warm ionized medium) and emission from carbon monoxide and its isotopes (tracing the molecular medium).
This thesis represents a bridge between numerics and observations towards the effort
to understand Galactic and extragalactic turbulence and it is just the beginning (i.e. further studies are being conducted that could not be included here). The use of multiple techniques can provide a more accurate indication of the  turbulence parameters of interest.

Event Details

Jul 29, 2014


4421 Sterling Hall

Thesis Defense

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