Galactic Star Formation
Dr Sarah Ragan is a Lecturer in the School of Physics and Astronomy. Her main research focus is determining the conditions necessary for star formation and how they vary with galactic environment. She uses a wide range of observational techniques to address this question, from molecular line to fine structure line emission to probe the full range of physical conditions in the ISM.
Abstract
Galactic plane surveys of the Milky Way in a variety of gas or dust tracers give us different perspectives on how the physical conditions of the interstallar medium vary throughout the Galaxy. The Herschel Infrared Galactic Plane Survey (Hi-GAL) covers the peak of the spectral energy distribution of dense, cold dust and thus supplies an essential part of the observational description of the conditions necessary for star formation in our Galaxy. With a catalogue of over 100000 compact Hi-GAL sources, I will discuss how star formation varies as a function of Galactocentric radius and proximity to spiral arms. This allows us to revisit several long-standing questions about the effect large-scale Galactic properties have on star formation on parsec scales. Moreover, with a comprehensive profile of the Milky Way over kiloparsec scales, these results provide a more detailed context in which to understand star formation in external galaxies.