Mini-Beatty Lectures 2005/2006

Roger Blandford

Director, Kavli Particle Astrophysics and Cosmology Institute
Chen Professor of Physics, Stanford University

Public Lecture

Thursday January 5th 2006, 19:00
Moyse Hall, Arts Building

Black Holes:
The End of Time or a New Beginning?

Scientific Lecture

Friday, January 6th 2006, 15:30
Keys Auditorium, Rutherford Physics Building

Electromagnetic Explosions

Black holes and neutron stars are responsible for remarkably powerful outbursts spanning a large range of energies and timescales. The recent outburst from the magnetar explosion associated with SGR 1806-20 released 10³⁸ Joules of energy with a rise time of 300μs. Quasars, by contrast can release more than 10⁵⁵ Joules over hundreds of millions years.

Many of these phenomena are intrinsically relativistic and plasma is observed to move with speeds close to that if light. It is widely believe that electromagnetic field is involved in the powering of these sources, though our understanding of fundamental mechanisms involved remains sketchy and the pathways followed by the power is still controversial. In this talk, I will summarize recent observations of relativistic explosions and make the case that the energy is transported essentially electromagnetically. Particular attention will be given to the description of magnetars, blazar jets and radio pulsars.