Name: Sioree Ansar
Affiliation: Indian Institute of Astrophysics, Bangalore
Conference ID : ASI2022_297
Title : Bar Formation and Destruction in the FIRE2 Simulations
Authors : Sioree Ansar ^(1,4), Robyn Sanderson ^(1,2), Sarah Pearson ^(1,3) Center for Computational Astrophysics, Flatiron Institute ^1 , University of Pennsylvania ^2 , New York University ^3 , Indian Institute of Astrophysics ^4
Abstract Type: Poster
Abstract Category : Extragalactic Astronomy
Abstract : One of the long standing questions about bar instabilities in galaxies is how they form. Do they form during galaxy interactions or do they form in isolation during secular evolution of galaxies? Studies using individual galaxy formation simulations have explored both formation mechanisms in controlled simulations with fine tuned initial conditions. Once formed, the bars in these systems appear to last for several Gyrs. But are galactic bars stable once formed or are they transient in nature? Do bars get destroyed? Cosmological simulations provide a more realistic environment for bar evolution as galaxies interact and merge with multiple satellite galaxies throughout the evolution history. In this work, we look at the 13 high resolution Milky Way mass galaxies in the FIRE2 (Feedback In Realistic Environments) suite of zoomed-in cosmological simulations to first ask: do these galaxies form bars? We find examples of both bar formation due to satellite interaction and through secular evolution of galaxies. The back and forth sloshing motion of gas at the centres of these galaxies and stellar feedback prescription implemented in FIRE2 determine whether bar formation is favourable. We also estimate the bar properties, for example, bar length, corotation, bar pattern speed, duration for which they last etc. Some of the bars oscillate with different frequencies in space and time, and some of the bars show a transient nature, while others dissolve into an x-shaped bulges at the end of their evolution.