Prime Minister’s Research Fellowship (PMRF)
Biju Saha
Academic background:
I completed my Bachelor’s degree in Physics (with Hons.) from St. Xavier’s College, Kolkata (Autonomous) in 2020 and thereafter received the Masters of Science degree in Physics from Jawaharlal Nehru University, New Delhi in 2022. I joined Ph.D. at IISER Tirupati in August 2022 and am currently working with Dr. Arunima Banerjee on galactic dynamics.
Research interest(objectives):
My research interest particularly lies in investigating the dynamics of a specific category of galaxy, known as the lopsided galaxy. Disk galaxies exhibit various non-axisymmetric features in their disc morphology. The well-known asymmetries that develop in the disc are the bars and spiral arms. Lopsidedness is another promiscuous non-axisymmetric feature in the galactic disc where the gas or stellar component of the galaxy is much extended along one half of the galactic disk than that along the other half. Lopsidedness can also be attributed to the presence of a bar that is offset from the center of the galaxy. Numerical simulations show that minor mergers, tidal interactions with the neighboring galaxies, or asymmetrical accretion of gas, are the possible cause of lopsidedness. However, the state-of-the-art simulation results could not explain several independent statistical properties of the observed lopsided galaxies which also includes the presence of lopsidedness in isolated galaxies. Further, the ubiquity and hence the stability of lopsided features of a galaxy is a dynamical problem which is not clearly understood yet. The main objective of my research is to systematically investigate the origin of disk lopsidedness using orbital dynamics, numerical simulations and machine learning techniques.
Advisor information:
Dr. Arunima Banerjee is an astrophysicist and associate professor at the Department of Physics, IISER Tirupati. Her broad research area is theoretical astrophysics focusing on modelling and simulation as applied to dynamics of galaxies, application of Bayesian statistics, machine learning, data science in galaxy astrophysics, alternative theories of gravity etc. Further information can be found on her webpage.
Courses taken:
- 4 courses (of 16 credits) and 2 audit courses were taken in the first two semesters of the Ph.D. program.
Teaching Assistantships:
- Introduction to Computer Programming (CSA 211, BSMS 2022 Batch, 3rd semester)
- Classical Mechanics I (PHY222, BSMS 2022 Batch, 4th Semester)
PMRF TA ship:
- Mathematical Methods in Physics I (8 weeks, NPTEL Live Interaction Session, Jan 2024): Recorded Sessions are available here.
- Quantum Mechanics and Free electron Theory (Mechanical Engineering, 1st Semester, Sri Venkateswara College of Engineering).