Clemson University

Colloquium: Dr. Jordi Bustamante, Oak Ridge National Laboratory

Colloquium

Department of Physics and Astronomy

Clemson University, Kinard Lab of Physics, G01, Lecture Hall

Thursday, February 1, 2018, 4:00 pm

Dr. Jordi Bustamante

Oak Ridge National Laboratory

Multi-dimensional Simulations of Mixing in Classical Novae

Abstract: Classical novae are explosive phenomena that take place in stellar binary systems. They are powered by mass transfer from a low-mass, main sequence star onto a white dwarf. The material piles up under degenerate conditions until a thermonuclear runaway ensues. The energy released by the suite of nuclear processes operating at the envelope heats the material up to peak temperatures about (0.1-0.4) GK. During these events, material enriched in CNO and other intermediate-mass elements, are ejected into the interstellar medium. To account for the gross observational properties of classical novae (in particular, a metallicity enhancement in the ejecta above solar values), 1D models often assume mixing between the (solar-like) material transferred from the companion and the outermost layers (CO- or ONe-rich) of the underlying white dwarf. The origin of the large enhancements and inhomogeneous distribution of chemical species observed in high-resolution spectra of ejected nova shells has, however, remained unexplained for almost half a century. I will present multi-D simulations of classical novae with the FLASH code, and will discuss the role of Kelvin-Helmholtz instabilities as a natural mechanism for self-enrichment of the accreted envelope with core material. Such mixing also naturally produces large-scale chemical inhomogeneities. Both the metallicity enhancement and the intrinsic dispersions in the abundances are consistent with the observed values. 

Bio sketch: Dr. Bustamante is a theoretical astrophysicist interested in understanding the nature of stellar explosions, such as classical novae and core-collapse supernovae. He received his PhD in Astrophysics in 2011 from the Technical University of Catalonia. He focuses on understanding the mixing processes operating at the core-envelope interface, and how the convective front progresses in nova outbursts. In 2012, he moved to NC State University as a postdoc and started working on core-collapse supernovae, as well as continuing to work on novae. As a postdoc at ORNL he performs multi-dimensional hydrodynamic simulations to study the interplay between turbulence and the dynamics of the explosion during a supernova event."

Refreshments will be served after the presentation in the P&A Café.

Thursday, February 1 at 4:00pm to 5:00pm

Kinard Laboratory of Physics, G01 Kinard Lab
140 Delta Epsilon Ct., Clemson, SC 29634, USA

Event Type

Speakers

Departments

College of Science, Physics and Astronomy

Target Audience

Faculty, Students, Undergraduate, Graduate

Contact Name:

Amanda Ellenburg

Contact Phone:

864-656-0343

Contact Email:

aellenb@clemson.edu

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