Abstract
Observations of ultracompact and hypercompact H II regions have shown time variations in their radio-continuum flux (Franco-Hernández & Rodríguez 2004; Galván-Madrid et al. 2008), suggesting that (some of) these ionized regions harbor stars that are still accreting from an infalling neutral accretion flow that becomes ionized in its innermost part (Keto 2007). We present an analysis of the flux variation of H II regions formed in the simulations incorporating self-gravity and both ionizing and non-ionizing radiation presented by Peters et al. (2010a,b,c). According to this model, a small but non-negligible fraction (~10%) of observed H II regions should have detectable flux variations (larger than 10%) in timescales of 10 years.
