Juergen Ott (NRAO)

Juergen Ott Colloquium: Molecular Gas in Nearby Galaxy Cores

Marsfield

Abstract

A large fraction of molecular gas is found in the centers of galaxies.
This is due to the peculiar dynamical forces of a disk, frequently with
a central bar, that funnels gas from the disk to the central
gravitational well. In the process, a large fraction of gas in converted
from an atomic to a molecular state, which can turn into the birthplaces
of new stars. In some cases, however, the strong cloud-cloud collisions
and heating sources reduce the star formation that would be expected
given the molecular mass. In other cases, a starburst is triggered that
is characterized by an extreme density of star formation events for a
short period of time. Starbursts and AGN also return large amounts of
energy back to the local environment, or produce large bi-conical
outflows of gas into the halo. I will show how we can use molecular
lines to characterize the events of star formation and feedback in
nearby galaxies. Examples are our Galactic Center as well as nearby
starburst and active galaxies. ATCA, ALMA and VLA data with a new
generation of broad-band front and backends play a crucial role in
deriving the physical parameters of the central regions of nearby
galaxies. This is important to understand galaxy evolution, the star
formation history of galaxies across cosmic time, and the distribution
of metals in and outside of galactic environments.