The Co-Evolution of Wind Blown Bubbles and Photo-Ionized Gas

Lachlan Lancaster (Columbia University)

February 10, 2025

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Abstract: Feedback from massive stars is the main regulator of star formation in giant molecular clouds (GMCs) where all star formation is observed to occur. Through their powerful radiation fields, these stars act to disperse the clouds that made them in multiple. Two of the most powerful mechanisms are bubbles blown by the shocked gas created by winds from these stars and the over-pressurized, ionized gas created by the stars’ hard ionizing spectra. In this talk I will review how these two mechanisms impact one another and physical principles for how to quantify their relative importance. I will show that, for parameters relevant to Milky-Way like GMCs and dense, low-metallicity environments as may be present in the high-redshift universe, both mechanisms are of nearly equal importance. To better understand this scenario, I develop a semi-analytic “Co-Evolution Model” for the evolution of both feedback mechanisms together and test the model against 3D Radiation Magneto-Hydrodynamic simulations. I will review possible improvements to the model and how it could potentially be used for inference based on observations of star-formation in the nearby and distant universe.