Peter Curran

Mullard Space Science Laboratory, University College London

torek, 4. 5. 2010, ob 15h v F7

I will introduce Gamma-ray bursts (GRBs), which are the most luminous and distant observable explosions in the Universe. I will explain how they are produced by a collimated ultra-relativistic outflow (a jet) emerging from the deep potential well of a massive star that has collapsed into a black hole. Within these jets, shock fronts accelerate charged particles to the relativistic speeds required so that they may radiate electromagnetically via synchrotron emission. Fundamental to the acceleration process is the electron energy distribution index and here I will examine the constraints placed on the distribution index by the observed properties of gamma-ray bursts. Given that the acceleration process applies to many astronomical jet sources, such as those from X-ray binaries and AGN (as well as particle acceleration in the solar wind and supernovae, and the acceleration of cosmic rays), the accurate measurement of the distribution of p is of fundamental importance to differentiate between the possible theories of electron acceleration at any relativistic shock front.