2024-04-18
(木) 宇宙物理学セミナーUTAPwiki/セミナー/宇宙物理学セミナー
presenter ： Kazuya Takahashi
Title ： Imaging gamma-ray burst jet structures with radio afterglows
Abstract ： A relativistic jet is deeply related to high-energy astrophysical phenomena such as gamma-ray bursts (GRBs) and activa galactic nuclei,
while its formation mechanism is not well understood. The structure of a relativistic jet will be a clue to the mystery of the formation mechanism.
Recently, GRB jets have been thought to possess a non-trivial jet structure characterized by an angular distribution of energy, which has been revealed by the electro-magnetic counterparts (GRB 170817A and its afterglow) of the first gravitational wave signal from a binary neutron star merger, GW170817.
However, there are many possible jet structures that can reproduce the observed GRB afterglow properties.
In this talk, we propose that the degeneracy of the jet structure will be resolved by imaging a GRB jet with Very Long Baseline Interferometry (VLBI) techniques in afterglow phases. We demonstrate that radio afterglow images highly depend on the jet structure by calculating images of each propagating jet, and that they can be distinguished with sub-milli-arcseconds' resolution for events similar to GRB 170817A if it takes place within 100 Mpc.
The next-generation VLA (ng-VLA) is an example of future planned VLBIs with a high resolution and high sensitivity.
Time ： 13:00-14:00
Venue ： RESCEU Seminar Room, ground floor, Sci Blg 4
content：
papers in presentation
Author(s)TitleYear, Journal,Number(,Link)
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