Snehalata Sahu

I am a postdoc research fellow (joined 2022) in the Astronomy and Astrophysics group at the University of Warwick, working on white dwarfs with Pier-Emmanuel TremblayLink opens in a new window and Boris GaensickeLink opens in a new window.

I am currently analyzing the HST/COS high-resolution ultraviolet (UV) spectroscopy survey data of DA (hydrogen-dominant atmospheres) white dwarfs (WDs). The atmospheric parameters of WDs, such as effective temperature and surface gravities, are extensively studied using optical spectroscopy and photometry observations; however, there are fewer studies using UV spectroscopy. The main motivation of this work is to search for planetary debris around young white dwarfs, estimate the abundances using UV spectroscopy, check their variation with WD parameters (mass, cooling age, etc.), provide a comparative analysis of the atmospheric parameters determined from UV and optical estimates from different studies, etc. Recently, we have also utilised this spectroscopic sample to understand the local interstellar medium, study the UV extinction correlation with 3D dust-extinction maps, and estimate the bias in the optical extinction.

I am also working on the spectroscopic survey of 100 parsecs sample to be observed with the 4-meter multi-object spectroscopic telescope (4MOSTLink opens in a new window). We are interested in obtaining the low-resolution spectra of main-sequence stars (up to spectral types M) covering the wavelength range 370–950 nm, which will be useful for studying their basic properties.

Apart from white dwarfs, I am also interested in the study of hot stellar populations (horizontal branch stars, exotic stars such as Blue Stragglers) in Globular clusters using multi-wavelength data. I obtained my Ph.D. in 2020 from the Indian Institute of Astrophysics, Bengaluru where I studied these UV stellar populations using Ultraviolet data from AstroSat/UVIT, HST, and other surveys.