Detecting stellar-wind bubbles through infrared arcs in HII regions

摘要: Mid-infrared arcs of dust emission are often seen near ionizing stars within HII regions. A possible explanations for these is that they could show the outer edges asymmetric stellar wind bubbles. We use two-dimensional, radiation-hydrodynamics simulations bubbles regions around individual to predict infrared properties region. assume and gas dynamically well-coupled (composition, size distribution) same in region as outside it, bubble contains no dust. post-process make synthetic intensity maps at wavebands using TORUS code. find edge a emits brightly 24um through starlight absorbed by grains re-radiated thermally infrared. This produces bright arc slowly moving have bubbles, even cases where there bow shock or any corresponding feature tracers emission. The decreases exponentially from with increasing distance star because temperature distance. distribution composition has quantitative but not qualitative effects on our results. Despite simplifications model, we good agreement observations RCW120, can provide physical differences. Our model an shape CD -38 11636 comparable brightness. suggests O may be revealing extent although excluded other explanations.