Date:
Tue, 16/12/201412:30-13:30
TITLE: A paradigm shift in understanding gamma-ray bursts
ABSTRACT: Since the launch of Fermi in 2008, a prime focus had been given to understanding the physical origin of the prompt emission from gamma-ray bursts (GRBs), which holds the key to understanding of their nature. While the problem is still far from being solved, in recent years we are witnessing a "paradigm shift", as the existence of a thermal component (on top the non-thermal emission) becomes evident. I will describe some latest results and the recent theoretical breakthroughs in understanding how the naively expected "Planck" spectrum can be broadened and resemble the observed spectra. I will discuss some novel effects and theoretical ideas relevant for the study of many astronomical objects. As a few examples, I will show how emission from the photosphere can be observed to have high degree of polarization; how it can be used to infer the jet magnetization; and more.
ABSTRACT: Since the launch of Fermi in 2008, a prime focus had been given to understanding the physical origin of the prompt emission from gamma-ray bursts (GRBs), which holds the key to understanding of their nature. While the problem is still far from being solved, in recent years we are witnessing a "paradigm shift", as the existence of a thermal component (on top the non-thermal emission) becomes evident. I will describe some latest results and the recent theoretical breakthroughs in understanding how the naively expected "Planck" spectrum can be broadened and resemble the observed spectra. I will discuss some novel effects and theoretical ideas relevant for the study of many astronomical objects. As a few examples, I will show how emission from the photosphere can be observed to have high degree of polarization; how it can be used to infer the jet magnetization; and more.