Barred galaxies in cosmological zoom-in simulations: the importance of
  feedback
  Bars are a key factor in the long-term evolution of spiral galaxies, in their
unique role in redistributing angular momentum and transporting gas and stars
on large scales. The Eris-suite simulations are cosmological zoom-in, N-body,
smoothed-particle hydrodynamic simulations built to follow the formation and
evolution of a Milky Way-sized galaxy across the build-up of the large scale
structure. Here we analyse and describe the outcome of two particular
simulations taken from the Eris suite - ErisBH and Eris2k - which mainly differ
in the prescriptions employed for gas cooling, star formation, and feedback
from supernovae and black holes. Our study shows that the enhanced effective
feedback in Eris2k, due to the collective effect of the different micro-physics
implementations, results in a galaxy which is less massive than its ErisBH
counterpart till z~1. However, when the stellar content is large enough so that
global dynamical instabilities can be triggered, the galaxy in Eris2k develops
a stronger and more extended bar with respect to ErisBH. We demonstrate that he
structural properties and time evolution of the two bars are very different.
Our results highlight the importance of accurate sub-grid prescriptions in
cosmological zoom-in simulations of the process of galaxy formation and
evolution, and the possible use of a statistical sample of barred galaxies to
assess the strength of the stellar feedback.
