Andrew Cumming

Physics Department McGill University Ernest Rutherford Physics Building 3600 University Street Montréal, QC Canada   H3A 2T8 Téléphone : 514-398-6494 Télécopieur : 514-398-8434 Courriel: cumming@physics.mcgill.ca Web: http://www.physics.mcgill.ca/~cumming/

Champ de recherche : I am a theoretical astrophysicist, primarily studying compact objects, high energy astrophysics, and extrasolar planets.

Description du projet de recherche :
I am a theoretical astrophysicist, primarily studying the physics of compact objects and extrasolar planets. A major focus is on understanding the structure and evolution of neutron stars. Having narrowly avoided collapse to a black hole in a supernova explosion, a neutron star contains matter that is compressed to a density greater than an atomic nucleus, and initially heated to temperatures of more than a billion degrees. The strength of gravity on the surface is one hundred billion times larger than the gravity on Earth, with magnetic fields vastly greater than the strongest laboratory magnets. These exotic objects therefore give us a unique chance to study material under extreme conditions of density, temperature, gravity, and magnetic fields. Much has been learned about neutron stars in recent years, with observations at all wavelengths, raising questions about the origins and evolution of neutron star spin and magnetism, the interior structure of the neutron star, and the properties of neutron stars interacting with a companion star in a binary system. I take a theoretical approach to these problems, with the general aim of using comparisons with observations to learn about the underlying physics. Recently I have worked on thermonuclear explosions in the surface layers of neutron stars, and the physics of magnetic field evolution in neutron stars. These are fascinating problems which involve a range of different physics, including the physics of magnetized fluids, nuclear physics, radiation transport, and electrodynamics. I also have a major interest in extrasolar planetary systems. Planets have now been detected around nearly 150 nearby stars, mostly by looking for the tell-tale wobble of the star as the star and planet orbit their common center of mass. My current work is on studying the statistical distributions of extrasolar planet masses, orbital periods and eccentricities. These properties have a lot to tell us about the physics of how planets form and evolve, and where our Solar System fits in to the general population of planets in the Galaxy.