| Name: | Vishwajeet Vishwajeet |
| Affiliation: | IIT Bombay |
| Conference ID : | ASI2024_966 |
| Title : | GRB 230204B: A highly energetic And Fast Fading GRB |
| Authors : | Vishwajeet Swain 1, Harsh Kumar 1,4, Dvita Saraogi 1, Poonam Chandra 5, Tomás Ahumada, Ankur Ghosh 7, Kuntal Misra , Gaurav Waratkar 1, Utkarsh Pathak 1, Varun Bhalerao 1, G. C. Anupama 2, Sudhanshu Barway 2, Kaisang Angail 3, Rigzin Norboo 3 |
| Authors Affiliation: | 1 Department of Physics, IIT Bombay, Powai, Mumbai - 400076, India
2 Indian Institute of Astrophysics, Bengaluru-560034, India
3 Indian Astronomical Observatory, Hanle-194404, India
4 Harvard College Observatory, Harvard University, 60 Garden St. Cambridge 02158 MA
5 National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville VA 22903, USA
6 Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125, USA
7 Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital - 263 001, India |
| Mode of Presentation: | Oral |
| Abstract Category : | High Energy Phenomena, Fundamental Physics and Astronomy |
| Abstract : | The Gamma-Ray Burst (GRB) 230204B stands out from the rest of the GRB population with its tremendously energetic (E_iso > 10^54 ergs) characteristics. A distinctive feature is the rest-frame peak energy of 2400 +- 140 keV, placing GRB 230204B among the rarest events of its kind. The optical afterglow of GRB 230204B was first discovered by the GROWTH-India Telescope (GIT), following the detection of its prompt emission through the MAXI/GSC nova alert system. GIT discovery of optical afterglow precisely localised GRB 230204B in the sky. The subsequent observations show the rapid decline of the afterglow, characterized by a single power law index of 1.85 +- 0.01. Such a rapid decline has been only seen in a very small fraction (11%) of GRB afterglows. We used a multi-wavelength approach to perform detailed analysis of this GRB, shedding light on the physical properties of the jet and its interaction with the surrounding ambient medium. Assuming a Top-Hat jet structure interacting with uniform circumburst medium, we used the afterglowpy to model the multi-band lightcurve. In addition to the afterglow, we conducted a comprehensive analysis of the GRB's prompt emission, statistically comparing it with other GRBs. We also estimated the initial Lorentz factor of the jet, defining lower and upper limits based on early afterglow emissions. We report the comprehensive analyses of the prompt and afterglow emission associated with GRB 230204B, unveiling its physical properties that set it apart from other GRBs. |
