2025/05/28 by Lachlan Lancaster, Jeong‐Gyu Kim, Lancaster, Lachlan +8 · 2 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.2505.22730
openalex publication_date 2025/05/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We propose a new framework for the simultaneous feedback of stellar winds and photo-ionizing radiation from massive stars, distinguishing the locations where forces are applied, and consequences for internal spatio-temporal evolution of the whole feedback bubble (FB). We quantify the relative dynamical importance of wind-blown bubbles (WBB) versus the photoionized region (PIR) by the ratio of the radius at which the WBB is in pressure equilibrium with the PIR, R\rm eq, to the Strömgren radius, R\rm St. ζ≡ R\rm eq/R\rm St quantifies the dynamical dominance of WBBs (ζ> 1) or the PIR (ζ< 1). We calculate ζ and find that, for momentum-driven winds, 0.1 \lesssim ζ\lesssim 1 for the star-forming regions in (i) typical Milky Way-like giant molecular clouds (GMCs), (ii) the most massive of individual OB stars, and (iii) dense, low-metallicity environments, relevant in the early universe. In this regime, both WBBs and the PIR are dynamically important to the expansion of the FB. We develop a semi-analytic Co-Evolution Model (CEM) that takes into account the spatial distribution of forces and the back reactions of both the WBB and PIR. In the ζ<1 regime where the CEM is most relevant, the model differs in the total FB momentum by up to 25% compared to naive predictions. In the weak-wind limit of ζ≪ 1, applicable to individual OB stars or low-mass clusters, the CEM has factors \gtrsim 2 differences in WBB properties. In a companion paper we compare these models to three-dimensional, turbulent hydro-dynamical simulations.