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Upcoming Seminar/Colloqium

Topic:

Afterglow Emission and Multimessenger Components in Gamma Ray Bursts

Speaker : Dr. Jagdish C. Joshi
Affiliation : Nanjing University China
Date & Time :
Venue : ARIES auditorium
Abstract :

Gamma Ray Bursts (GRBs) are the transient events, which indicate either explosion of a massive star or merger of two compact objects. These explosions create relativistic blastwaves whose expansion leads to external shocks, if the jet is able to plough out the star envelope. On the contrary, the electromagnetic radiation is chocked for a hidden jet and these class of GRBs could be sources of TeV-PeV neutrinos. In the former case, properties of the emitting region i.e. non-thermal particle spectrum, magnetic amplification and microphysical parameters etc can be probed by monitoring and modelling of afterglow radiation. Recent detection of very high energy (VHE, > 100 GeV) gamma rays from GRBs has opened a possibility to test emission mechanisms late in the afterglow phase. This is in confirmation with synchrotron self-Compton (SSC) component in GRBs predicted by theoretical models.

In this talk, I will describe SSC modelling which is useful to understand the multiwavelength afterglow emission. Further I will discuss the properties of the chocked GRBs as a possible candidate of neutrino sources. The IceCube and gamma ray detectors hold the key to constrain the emission mechanism of afterglow.

About Speaker :

Dr. Jagdish Joshi is a postdoctoral fellow at Nanjing University, China. He is currently visiting ARIES.