I am an ASTRO3D PhD student at the International Centre for Radio Astronomy Research (ICRAR), University of Western Australia (UWA). I hold an MSc. degree from the Department of Astronomy, University of Cape Town (UCT), where I was the recipient of the SALT-SAAO Prize MSc Scholarship in 2021 conferred by the South African Astronomical Observatory (SAAO). I study the link between galaxies and multiphase gas across environments ranging from the dense Inter-Stellar Medium to the diffuse cluster outskirts using radio interferometry (HI emission), UV/Optical QSO absorption line spectroscopy, hydrodynamic simulations, and Integral field spectroscopy.
Briefly, disc galaxies such as the Milky Way are embedded in spherical gaseous mediums and they require a constant supply of gas to sustain forming stars. The surrounding medium comprises mostly hot but also cold gas. The existence of cold clouds in the medium has raised many intriguing questions. These clouds could either be gas falling into the stellar disc or gas removed at earlier times and their origin can be investigated by studying the chemical signatures, kinematics, environment, etc. Subsequently, numerous theories have been postulated for the existence of these clouds. However, due to observational, theoretical, and computational challenges, we do not yet fully understand gas flows in and around galaxies. To answer these and deeper questions therein, we must compare multi-wavelength, multi-epoch, and multi-technique observations with various theoretical models and simulations of multi-phase gas in and around diverse sets of galaxies. Over the past couple of years, I have delved into multiple wavelengths, observational techniques, as well as idealized hydrodynamic simulations to study the connection between galaxies and multi-phase gas across various environments.
Brief research trajectory
I recently took up a visiting project to collaborate with Dr. Jonathan Stern to explore a new framework for the formation of warps and extraplanar gas. Here, I employ analytic calculations, idealized hydrodynamic simulations, and comparisons with observations to study the consequence of misaligned hot-mode accretion (cooling flows) from the circumgalactic medium. A part of this work involves creating projected mock 3D HI cubes (ppv) from simulated 6D snapshots (pppvvv). This work is ongoing and the manuscript is in its preliminary stages.
My MSc. dissertation supervised by Dr. Moses Mogotsi and Prof. Matthew A. Bershady, is titled “Kinematics of neutral hydrogen in interacting galaxies in two groups from the MeerChoirs survey”. For this, I reduced interferometric data and analyzed the kinematics of the neutral hydrogen emission in two low-mass, late-type dominated groups featuring varying levels of interactions. Luckily, I got to work with what is currently the most sensitive radio telescope for observing neutral hydrogen in the local universe, MeerKAT, an SKA-mid precursor. The manuscripts from this work are currently under preparation.
I am currently leading MeerRings, a MeerKAT campaign, to carry out the first resolved, deep, and systematic census of the neutral hydrogen and L-band continuum in a sample of eight Collisional Ring Galaxies (CRGs). It will also be the first systematic investigation of anomalous gas resulting from a well-known class of interactions. This campaign is in its nascency and the observations are ongoing.
In my work with Prof. Anand Narayanan at the Indian Institute of Space Science and Technology (IIST, Kerala, India), I employed UV/optical QSO absorption line spectroscopy with archival data from the Hubble Space Telescope and Keck Observatory to study the small-scale physical and chemical properties of multi-phase gas in the extended environments around galaxies. This collaboration yielded three journal articles amidst the COVID-19 pandemic (Pradeep, Sankar, et al. 2020, Sankar et al. 2020, Sameer et al. 2022).
Fortunately, I am not just my work
Aside from astrophysical research, I enjoy a range of activities such as: reading philosophical novels; writing poetry; creating music; binging on - anime, sci-fi shows, and documentaries; outdoor activities such as gardening, hiking, and stargazing; and exploring open-source codes and cool software technologies. I also spend some time thinking about and working on climate action through personal lifestyle choices and pushing for systemic changes in my immediate environment.
I have filled this website with some of the poems that I have written over the years and some images from my gallery. I have also added some of the projects that I was able to bequeath life to through dedication and hard work. In other words, I am committing a small part of myself to a GitHub repository.
Thoughts think me, thought I
But I am but a thought
A hundred I exist
In a hundred minds, I fit
Zillion impressions persist
The hundred I coexist
Sometimes thoughts desist
But I never resist
For a hundred I exist
None of which is me