Galván-Madrid, Roberto, Peters, Thomas, Keto, Eric R., Mac Low, Mordecai-Mark, Banerjee, Robi, and Klessen, Ralf S. 2011. "Time variability in simulated ultracompact and hypercompact H II regions." Monthly Notices of the Royal Astronomical Society 416 (2):1033-1044. https://doi.org/10.1111/j.1365-2966.2011.19101.x
Ultracompact and hypercompact H II regions appear when a star with a mass larger than about 15 M&sun; starts to ionize its own environment. Recent observations of time variability in these objects are one of the pieces of evidence that suggest that at least some of them harbour stars that are still accreting from an infalling neutral accretion flow that becomes ionized in its innermost part. We present an analysis of the properties of the H II regions formed in the three-dimensional radiation-hydrodynamic simulations presented by Peters
