February 13 , 2008
3pm in Howey Physics Lecture Room 5

 

Bart Willems
Departments of Physics and Astronomy
Northwestern University

 

"Compact object binaries: stellar and binary evolution in the gravitational wave era"

The construction and planning of ground- and space-based laser interferometers has led to a massive surge of interest in sources of gravitational wave radiation during the past decade. Direct detection of these ripples in space-time will provide unprecedented tests of Einstein's theory of general relativity and open a brand new window on the universe unhindered by the main obstacles affecting electromagnetic radiation. Among the rich set of anticipated gravitational wave sources, binary star systems made up of compact remnants of stellar evolution are expected to be the most numerous class of gravitationally radiating objects. In this colloquium, I will look into the future and discuss the physics that will become accessible with the launch of the Laser Interferometer Space Antenna (LISA), the most ambitious gravitational wave observatory planned to date. I will particularly focus on binary star systems consisting of one or two white dwarfs, the evolutionary endpoints of more than 90% of the stars in the galaxy (including the Sun). Recent theoretical advances and observations by the Spitzer infrared space telescope show that the formation of circumbinary disks during mass-transfer episodes between the binary components can drastically affect the binary evolution, potentially resolving longstanding problems in white dwarf binary evolution and raising questions about neutron star and black hole binary formation. I will also show the unique opportunity offered by globular clusters and LISA to unveil white dwarf physics with LISA inaccessible through electromagnetic observation.