Research


The extent of adiabatic compression of radiative stars in deep Tidal disruption events

Co-authors: Eric R. Coughlin, Chris J. Nixon

The extent of adiabatic compression a star suffers has been debated since the starting days of TDE research and any consensus is yet to be reached. In this work, we continue on the analytic model developed by Norman et. al. (2021) and Coughlin et. al. (2022) and then simulate with Smoothed Particle Hydrodynamics (SPH) code to estimate the adiabatic compression a sun-like star suffers in events when a star enters deep within the tidal radius of the supermassive black hole. We find the compression is at least an order of magnitude lesser than what was estimated in the 1980s and the speculated nuclear detonation is highly unlikely.

Accepted in ApJ, Link to the paper: Stars Crushed by Black Holes

Dynamic stability of giant planetary atmosphere

Co-authors: Eric R. Coughlin , Andrew N. Youdin , Philip J. Armitage

The presence of a solid core can alter the usual Chandrasekhar criterion dictating the dynamic stability in non -trivial way. We have identified the region of instability in parameter space for planetary configurations consisting of a solid core and gaseous envelope. Our results has consequences for formation of giant planets in "core-accretion" paradigm.

The link to the paper: Dynamic Stability MNRAS

The eigen modes of oscillations

Region of Instability

Model gas giants

The normalized post-shock velocity


General relativistic settling solution for the post-shock fluid in core-collapse supernovae

Co-author: Eric R. Coughlin

We derive novel solutions for spherically symmetric accretion through standing shock considering the relativistic effects. Our solutions might change the SASI modes non-trivially.

Published: MNRAS Link to paper: Relativistic accretion solution through standing shock

Asteroseismology of Neutron stars: eyeing gravitational wave emission

co-authors: Chaitanya Afle, Duncan Brown, Eric Coughlin

Core collapse Supernovae can be a source of the gravitational wave. Asteroseismology reveals the oscillation modes of the nascent neutron star due to continuous hitting of the shocked material can be the dominant source of power in the gravitational wave emitted. The dominant track is identified with the f-modes and then we calculate the total energy in it.

Presented at: APS ; Link to abstract: Gravitational wave CCSNe

Does the Vacuum gravitate?

co-authors: Arnab Pradhan, Carl Rosenzweig

Well Rydberg atoms might tell, and probably its a "NO" !!!

submitted to PRL Link to paper: Vacuum gravitates?