ITC Colloquium - Sarah Jeffreson (ITC) and Azadeh Fattahi (Durham)


Thursday, October 1, 2020, 11:00am to 12:00pm


  1. Sarah Jeffreson (ITC) "The lifecycles of giant molecular clouds in Milky Way-like galaxies"

    Most stars in galaxies are formed within Giant Molecular Clouds (GMCs): large, cold and dense reservoirs of molecular hydrogen within the hierarchical structure of the interstellar medium. The rate and efficiency of galactic-scale star formation therefore depends on the properties and lifetimes of these clouds. In this talk, I will use a statistical sample of ~80,000 GMCs across three high-resolution simulations of Milky Way-like disc galaxies in the moving-mesh code Arepo to answer the following questions: (1) Do the physical properties of GMCs depend on the galactic-dynamical environment? (2) Do interactions between GMCs influence their evolution and internal star formation rates? (3) How does the GMC lifetime vary with spatial scale, and what are the physics that drive it? Finally, I will link the presented results to sub-millimetre observations of CO emission in nearby galaxies, and will discuss future work to explore the physics of GMC evolution in higher-pressure environments.

  2. Azadeh Fattahi (Durham)  "Surviving and destroyed dwarf galaxies: the build-up of the Milky Way's stellar halo"

    The hierarchical nature of galaxy formation in the standard model of cosmology (LCDM) predicts a diffuse stellar halo component around Milky Way-mass galaxies, formed from the accretion and disruption of dwarf galaxies. Using cosmological hydrodynamical simulations of Milky Way like halos, I will compare the properties of these destroyed dwarfs which built up the stellar halo with those of existing satellites. I will then connect these results with recent findings from the Gaia mission related to the major event in the formation history of the Milky Way.  

See also: Colloquium, 2020-21