Gas flow and the structure of the Galactic bar

University of Oxford
Higgs Centre Seminar Room, JCMB
Friday, November 20, 2015
13:00 to 14:00
The evidence that our galaxy is a barred galaxy will be summarised. The bar's
impact on local kinematics and on the flow of the ISM are significant lines
of evidence.  Hydrodynamical simulations will be used to examine critically
the conjecture that gas streamlines approximate closed orbits. It turns out
that the sound speed and numerical resolution both play significant roles in
structuring the flow. At high resolution the flow becomes unsteady, and there
are reasons to believe this unsteadiness is of practical importance. The
effect of varying the bar's strength is examined. The data point to a strong
and surprisingly slow bar. New models of our Galaxy in which dark matter is
fully dynamical confirm a significant uptake of energy and angular momentum by
the central portion of the Galaxy's dark halo.