Tuomas Kangas KTH will present "The behavior of GRB afterglows at late times in the 'standard' afterglow model"

Thursday 8 Oct 2020, 13:15 → 14:00 Europe/Stockholm

https://stockholmuniversity.zoom.us/j/61497979368

Abstract: Interpreting late-time observations of the afterglows of gamma-ray bursts is an important part of understanding the physics behind these explosive events. In order to study the energetics (and thus power source) of the GRB, and the mechanism of the so-called jet break -- a steepening in the afterglow light curve caused by relativistic beaming effects -- it is important to observe the afterglow after the jet break at multiple wavelengths. In this talk I will present two connected afterglow modeling studies that demonstrate this. Firstly, I will show results from the follow-up and numerical modeling of GRBs 160509A and 160625B as part of a long-term project targeting energetic GRBs detected by Fermi/LAT and discuss the implications of their problematic late-time behavior, especially in the radio. Second, I will present an effort to analytically model a larger sample of other afterglows observed after the jet break, from X-ray to radio, and how their late-time light curves, again especially in the radio, may deviate from the 'standard' picture of GRB afterglows.