Professor Hardee's research involves study of the highly collimated jet outflows observed to emanate from protostellar systems, from extragalactic radio sources and quasars, and thought to be responsible for gamma-ray bursts. Research conducted locally includes theoretical analysis of the magnetohydrodynamic and plasma processes associated with the jets. Studies of relativistic jet dynamics have been carried out in collaboration with Dr. Philip Hughes at the University of Michigan in Ann Arbor. Additional research in collaboration with Dr. Ken-Ichi Nishikawa at the NSSTC (National Space Science & Technology Center) in Huntsville, Alabama involves the study of particle acceleration in collisionless shocks associated with relativistic jets. He is also involved in modeling extragalactic relativistic jet structures in collaboration with Dr. Craig Walker (NRAO/VLA), Dr. Jean Eilek (New Mexico Tech & NRAO) and Dr. Andrei Lobanov (Max Planck Institute). Professor Hardee's research has received support from the NSF and NASA.
keywords:magnetohydrodynamics of collimated outflows, Plasma astrophysics, extragalactic astronomy
This project will involve investigation of magnetohydrodynamic flows that are of interest in astrophysical systems. This project will continue the present study of the dynamics of collimated outflows such as those observed in many extragalactic radio sources, and will extend the study to the dynamics of collimated outflows such as those observed in many extragalactic radio sources, and will extend the study to the dynamics of collimated outflows in Seyfert Galaxies, and protostellar systems. The investigation involves comparison between analytical analysis of the time dependent magnetohydrodynamic fluid equations and linearized time dependent magnetohydrodynamic fluid equations, and numerical simulations and numerical modeling of collimated outflows. A major objective of this project is to perform fully three dimensional numerical simulations and compare results with analytically developed theory. A second objective is to use the results to learn how outflow morphology is influenced by the external environment, by the presence of dynamically significant magnetic fields, and by radiative cooling. A third objective is to model the emission from collimated outflows and model selected objects. The objectives can be achieved by performing a combination of twodimensional and fully three dimensional fluid and MHD simulations of extragalactic light continuum jets, and protostellar and other radiatively cooled heavy jets. The analytical theory is used to establish model dependence on parameters and for its predictive abilities.The physics of radio jets is still not well understood, and this research adopts a three pronged approach to the study of the effects of atmospheric gradients and magnetic fields on jet dynamics and radio source morphology. It will comprise an analyticalstudy of the time independent magnetohydrodynamic fluid equations, a linearized time dependent stability analysis of those equations, and a comparison of the results of these analyses with numerical simulations. Dr Hardee is one of the most thorough and productive workers in this field, and has developed a strong foundation of computational background for this program.
Astronomy, Extragalactic Astron & Cosmolo
