Ionizing Radiation in Local Galaxies: Expectations versus Reality

Feedback from young, massive stars affects the interstellar medium (ISM) over a wide range in physical scales, from scales of individual stars and their ionised HII regions to galaxy-wide scales. High-resolution studies of HII regions and their surroundings offer a critical window to understand the connection between HII regions and their ionising stellar engines.

NGC 628 is a nearby, face-on grand design spiral galaxy. NGC 628 has appeared in both the Legacy ExtraGalactic UV Survey (LEGUS) with a complete catalog of the young clusters candidates from the Hubble Space Telescope and the Stars, Ionized Gas, Nebular Abundances Legacy Survey (SIGNALS; survey that gives a consensus of the ionised HII regions. This project will link the physical conditions of the ionised gas within the spatially resolved HII regions to the properties of the stellar population producing ionising photons. We will model the expected ionising photon output from the star clusters and compare this against the observed H-alpha luminosity of the HII regions. Any missing flux constrains the leakage of ionising photons into the ISM and places a constraint on the 'missing light' in star forming regions. This is critical to our understanding of how radiation can escape galaxies and has enormous implications for the re-ionisation of the early universe.  

This project will allow you to gain invaluable experience learning how to write your own code in Python, develop your critical thinking skills while we advance our understanding of star formation and galaxy evolution, and gain experience participating in a scientific collaboration. For more information about this potential research topic, or to discuss any related research area, please contact the supervisor.