The LMC's bar has several strange properties which are typically not shown by barred galaxies. It is offset from the disk center, tilted with respect to the disk plane, and does not drive gas inflows. Characterizing the LMC's bar is important to understand the origin of its strange nature, place the LMC in context with other barred galaxies, and understand the role of bars in the evolution of low mass galaxies.

In Rathore+2025(a), we precisely measure the 2-D geometry of the LMC's bar with Gaia DR3 data. We propose a novel solution to tackle crowding induced incompleteness in Gaia datasets, particularly for color selected Gaia sub-samples.

I gave a talk primarily focussed on this work in July 2024 at the Indian Institute of Astrophysics, slides can be found here.

Why does the LMC's bar show such strange properties despite being consistent with bar - galaxy scaling relations ?

In Rathore+2025(b), we show that tidal forces from the SMC is what primarily drives the LMC's bar out of equilibrium. In particular, the LMC bar's strange properties (offset, tilt and lack of gas inflows) can be explained if the LMC and SMC collided around 150 - 200 Million years ago ! Further, this collision significantly slows down the LMC's bar, potentially explaining the low observed pattern speed values.

Moreover, the SMC's torques on the LMC's bar during the collision can explain the LMC bar's tilt, provided the SMC's inner regions contain atleast 70% dark matter ! This is the first dynamical constraint on the SMC's pre-collision dark matter profile.

I gave a talk primarily focussed on this work in March 2025 at the Durham University (UK), slides can be found here.

The LMC and SMC are associated with very interesting observables like the gas stream, the bridge, LMC's off-centered bar, LMC's one-armed spiral to name a few, which are a likely consequence of galaxy interactions. The Clouds can give us a detailed understanding of how interactions affect dynamical processes in galaxies; like stellar orbits, bars, spirals and the distribution of dark matter. Accurate models of the Clouds are needed to use precision observations from Gaia, Hubble Space Telescope and other surveys to solve this complex dynamical problem. MEGHA simulations are a path forward ! This is work in progress.

S0 galaxies possess well defined stellar disks, but lack spiral arms and are generally quenched. However, there exists a significant number of S0s that show active star-formation. The prevailing theory for the origin of S0s relies on quenching mechanism. Thus, the existence of star-forming S0s poses a significant challenge towards understanding the nature of this class of galaxies. The origin of star-formation and the star-formation properties of such galaxies have been a subject of debate since the last two decades. We did a detailed study of star-forming S0s with resolved spectroscopic observations from the SDSS-MaNGA survey combined with deep optical imaging. We performed the first spatially resolved analysis of the star-formation properties of these galaxies and also attempted to settle the debate on the origin of star-formation in these galaxies.

The Hubble tension is a raging debate in cosmology about the current expansion rate of the universe, as quantified by the Hubble constant. Early universe probes like the Cosmic Microwave Background and late universe probes like the Cepheid-Supernova distance ladder give different values of the Hubble constant, the difference being highly significant statistically. One possible explaination for the Hubble tension could be physics beyond the framework of general relativity, like a time varying gravitational constant (G). In this work, we proposed a transition in the value of G at late times, and evaluated its affect on the physics of Cepheid variables and Supernova explosions, and thereby the distance ladder. We performed a careful statistical analysis to identify whether such a G transition can the solve the Hubble tension.