Astronomy and Astrophysics Seminars

Study of flows of the Solar Convective Zone: Differential Rotation and Surface Convection

by Mr. Samarth G. K.

Tuesday, September 1, 2020 from to (Asia/Kolkata)
at Zoom link: https://zoom.us/j/92487952506?pwd=a3lPUDBoQVNsVitZSmw1RU5xN1oyZz09 ( Meeting ID: 924 8795 2506, Passcode: 266608 )
Meeting ID: 924 8795 2506 Passcode: 266608
Description
The Sun is a main sequence star and its proximity to Earth enables us to study its structure and evolution in great detail. The Sun has a radiative core and an outer convective envelope. The motions in the convection zone are believed to govern the dynamics and evolution of the Sun. Specifically, the internal rotation of the Sun is thought to drive the activity cycle. Turbulent convection at the surface excites acoustic waves that propagate through the solar interior and form a discrete set of resonant modes. In this talk, I will describe the theory of normal mode coupling and the analysis to arrive at rotation rate of the Sun. We use the helioseismic time-series data from the Helioseismic Magnetic Imager (HMI) for this purpose. I will also discuss the development of a pipeline to process the raw, full-disk, line-of-sight Dopplergram images from HMI. I will present a novel technique that we developed to compute the radial, poloidal and toroidal convection spectrum using the processed Dopplergram images and compare the results with other techniques.