Lars Bildsten

Permanent Member, Kavli Institute for Theoretical Physics

Professor, Department of Physics

KITP, Kohn Hall

University of California, Santa Barbara

Santa Barbara, CA 93106

Phone: (805) 893-3979 Fax: (805) 893-2431

Biographical Sketch

Lars Bildsten joined the Kavli Institute for Theoretical Physics and the Physics Department at University of California, Santa Barbara in July 1999. He received his PhD in theoretical physics from Cornell University in 1991, where he held a Fannie and John Hertz Graduate Fellowship . Bildsten was then at Caltech for three years as the Lee A. DuBridge Research Fellow in Theoretical Astrophysics and received a Compton Fellowship from NASA in spring 1994. He was an assistant and associate professor in both the Physics and Astronomy departments at University of California, Berkeley from January 1995 through July 1999. While there, he was awarded an Alfred P. Sloan Foundation Fellowship in 1995 and a Hellman Family Faculty Fund Award in 1997. The Research Corporation designated him as a Cottrell Scholar in 1998. In 1999, he was awarded the Helen B. Warner Prize from the American Astronomical Society. Bildsten was cited for his fundamental work on stellar structure, including nuclear burning on neutron stars, the role of neutron stars as gravity wave sources, and the theory of lithium depletion. He was the 2000 Edwin Salpeter Lecturer at Cornell University and the 2004 Biermann Lecturer at the Max-Planck Institute for Astrophysics, and is presently a Foreign Associate of the Cosmology and Gravity Program of the Canadian Institute for Advanced Research.

National Service

During the most recent Decadal Survey of Astronomy and Astrophysics , Bildsten served on two Panels: High Energy Astrophysics from Space and Theory, Computation and Data Exploration. He was an elected member of the Executive Committee of the High Energy Astrophysics Division of the American Astronomical Society in 2000 and 2001 and the Executive Committee of the Division of Astrophysics of the American Physical Society from 2003-2005. He has served on many recent NRC panels, including Committee on Astronomy and Astrophysics from 2001 to 2005 and the Panel to Review the Science Requirements for the Terrestrial Planet Finder and Committee on Review of Progress in Astronomy and Astrophysics toward the Decadal Vision in 2005. He was a member of the NSF's Mathematical and Physical Science Advisory Committee from 2004 until 2007.

Research Interests

Overview

I primarily work in the field of stellar astrophysics, where my current efforts are focused on the physics of white dwarfs and their explosions as Type Ia supernovae. This includes the theoretical study of many different physical phenomena, including thermonuclear instabilities, propagating combustion fronts, detonations and stellar oscillations. I have considered the prospects for detection of coalescing neutron star/neutron star binaries at cosmological distances and accreting neutron stars in our Galaxy with the Laser Interferometer Gravitational Wave Observatory

Current Research Projects

Over twenty years of neutron star observations (either through X-rays from those which accrete or radio emission from those sources which are losing rotational energy via a magnetic field) have taught us much about these objects and raised many new questions. For neutron stars born in binaries, these questions include the spin period and magnetic field at birth, and the way these are changed by subsequent accretion. These issues recently came into further focus with the discovery of rapidly rotating (Ps<< s) radio pulsars with low (~ 108-109 G) magnetic fields. Confirming either of the conjectured origins for these objects (spin-up of a low magnetic field neutron star via magnetized accretion or accretion-induced collapse of a near Chandrasekhar mass white dwarf) requires a much better theoretical and observational understanding than we now have in hand.

I am attacking these broader issues through very directed theoretical and observational work on accreting neutron stars and white dwarfs. We know from X-ray observations that the continual accretion of matter drives the star far from equilibrium, resulting in a rapidly varying luminosity. Understanding the ultimate source of these variations tells us much about the spin, magnetic field strength and internal properties of the neutron star. Some of my recent work showed that unstable thermonuclear ignition of the accreted hydrogen and helium starts a nuclear burning "fire" that takes a finite time to spread around the star, giving rise to asymmetries that can modulate the signal from the nuclear burning at the neutron star spin period. I have also carried out much work on the structure and evolution of the neutron star ocean and crust, which is made of the ashes from the hydrogen/helium burning. This began with studies of the non-radial oscillations in the neutron star oceans and has evolved to more detailed work on the structure and composition within the deep accreted crust. Over the last five years, my research has spread into the studies of accreting white dwarfs and how they respond to surface and interior thermonuclear ignitions, sometimes resulting in Type Ia supernovae. I am also avidly interested in optical transients, some of which will soon be followed up by the Santa Barbara based Las Cumbres Observatory Global Telescope Network

Papers

Current Graduate Students working with me

Former Graduate Students. . where are they?

Former Postdocs

Current Collaborators

Lecture Notes and Talks

Teaching and UCSB Information

Family

Local Endeavors