The radiation process and the dynamics of the shock physics in relativistic outflows produced in gamma-ray bursts are largely elusive. In this talk, I will discuss the spectrum and polarimetric observations of the prompt emission of GRB160821A obtained from the Fermi gamma-ray space telescope and AstroSat respectively. Clear identification of the synchrotron emission during the strong flare of GRB 160821A at 135s has led to the identification for the first time, the onset of particle acceleration in a GRB jet. This observation provides a new and independent constraint on the properties of the outflow such as the Lorentz factor of the outflow and the emission radius.
Dr. Shabnam Iyyani obtained her Ph.D. in Astrophysics under the ‘Erasmus Mundus Joint Doctorate Fellowship’ from Stockholm University, Stockholm, Sweden in June 2015. After that, she joined as a Visiting Postdoc Fellow at TIFR, Mumbai, and then between 2016-2020, she was a Vaidya -Raychaudhuri Prize Fellow at IUCAA, Pune, India. She continued her work at IUCAA as INSPIRE Faculty Fellow until August 2020 prior to joining as Assistant Professor (also INSPIRE Faculty Fellow) at IISER-
Thiruvananthapuram, Kerala, India. She is an expert in the study of the prompt emission of GRB. This invited seminar is a part of the activities commemorating "75 years of India's Independence: Azadi ka Amrit Mahotsav" at ARIES.