Title: WISDOM: Molecular cloud properties and star-formation quenching

Speaker: Martin Bureau

Abstract: Molecular gas is the fuel for star formation in galaxies. Usingobservations from the mm-Wave Interferometric Survey of Dark Object Masses (WISDOM), that spatially resolve (1-30 pc) individual molecular clouds across the Hubble sequence, I will reveal a clear dependence of the nature of the molecular interstellar medium of galaxies on Hubble type, and present a simple diagnostic of cloud formation. I will then highlight the shortcomings of the usual virial approach to clouds as self-gravitating objects, and stress the importance of the external galactic potential and in-plane shear to regulate the dynamical states of clouds. I will also introduce a simple but powerful cloud-cloud collision formalism that accounts for the cloud properties of several nearby as well as high-redshift systems, and will note the peculiar properties of clouds within the bars of spiral galaxies. Finally, using diverse observations of star-formation tracers, I will discuss the impact of these different mechanisms on the star-formation efficiency of clouds and thus the quenching of star formation, particularly in galaxy nuclei and spheroids (morphological quenching).

Bio: Martin Bureau is a self-described galaxy guru, with an interest in anything and everything galactic. He is particularly interested in using observations and theoretical studies of the gas, stars, and dark matter that make up galaxies to constrain their formation and evolution. 

Martin is Professor of Astrophysics at the University of Oxford, and Lindemann Fellow and Tutor in Physics at Wadham College. He has been in Oxford for nearly two decades, following appointments at Columbia University as a NASA Hubble Fellow and at Leiden University. He obtained his PhD from The Australian National University and is originally from Montreal, Canada.

Time: 13:30-14:30, 22/Nov, Friday
Venue: Room 506 (Large seminar room), Department of Astronomy