Joel Tohlinetohline

Director Emeritus
Alumni Professor Emeritus of Physics

Ph.D., 1978 - University of California-Santa Cruz

Louisiana State University
Department of Physics & Astronomy
264 Nicholson Hall, Tower Dr.
Baton Rouge, LA 70803-4001
(225) 578-6851-Office
tohline@lsu.edu
Personal Home Page

Research Interests

Astronomy & Astrophysics

My research has stemmed from a central theme of trying to understand the hydrodynamical evolution of self-gravitating, astrophysical systems, particularly when the geometry of such flows demand a fully three-dimensional representation. I have studied in detail problems that relate to star formation, gas-dynamical flows in galaxies, and compact stellar objects (such as white dwarfs and neutron stars). If you are interested in gaining a better understanding of the mathematical tools and the physical concepts that underpin research efforts of this nature, I encourage you to browse through the on-line, graduate-level textbook entitled, "The Stucture, Stability, and Dynamics of Self-Gravitating Systems," that I have been developing since the mid-1990s. These research activities blend smoothly into the Integrative Graduate Education and Research Traineeship (IGERT) program in multiscale computational fluid dynamics that I have helped to establish in collaboration with Sumanta Acharya and numerous other colleagues across the LSU campus.

In order to be able to understand in a quantitatively reliable way how stars, molecular clouds, and galaxies behave during key dynamical phases of their evolution, my students and I have invested a great deal of time developing nontrivial computational algorithms to simulate fully three-dimensional, self-gravitating, compressible fluid flows and to visualize the results of these flows, which often can be quite complex. Details regarding the parallel algorithm that we presently use to simulate Newtonian astrophysical fluid flows can be found in D'Souza, Motl, Tohline, and Frank (2006); several digital animation sequences that we have produced to illustrate the results of a variety of our dynamical simulations can be found in this on-line journal reference as well. In collaboration with Luis Lehner we are extending these tools to follow relativistic fluid flows in time-evolving space-time metrics.

My research activities in these areas would not have been possible without the ongoing support of several key funding agencies; most notably, the U.S. National Science Foundation (NSF), the U.S. National Aeronautics and Space Administration (NASA), and the Louisiana Educational Quality Support Fund (LEQSF).

 

Current and Select Publications

  • M. D'Souza, P.M. Motl, J.E. Tohline, J. Frank, "Numerical Simulations of the Onset and Stability of Dynamical Mass Transfer in Binaries," [astro-ph/0512137] The Astrophysical Journal 643, 381 - 401 (2006).

     

  • C.D. Ott, S. Ou, J.E. Tohline, A. Burrows, "One-armed Spiral Instability in a Slowly Rotating, Post-Bounce Supernova Core," [astro-ph/0503187]The Astrophysical Journal Letters 625, L119-L122 (2005).

     

  • S. Ou, J.E. Tohline, L. Lindblom, "Nonlinear Development of the Secular Bar-Mode Instability in Rotating Neutron Stars," [astro-ph/0406037]The Astrophysical Journal 617, 490-499 (2004).

     

  • J.E. Tohline, "The Origin of Binary Stars," Annual Reviews of Astronomy & Astrophysics 40, 349 - 385 (2002).

     

  • L. Lindblom,J.E. Tohline, M. Vallisneri, "Non-Linear Evolution of the r-Modes in Neutron Stars," Physical Review Letters 86, 1152-1155 (2001).