Wind bubbles within H ii regions around slowly moving stars

摘要: Interstellar bubbles around O stars are driven by a combination of the star’s wind and ionizing radiation output. The contribution is uncertain because boundary between interstellar medium difficult to observe. Mid-infrared observations (e.g., H ii region RCW 120) show arcs dust emission stars, contained well within bubble. These could indicate edge an asymmetric stellar bubble, distorted density gradients and/or motion. We present twodimensional, radiation-hydrodynamics simulations investigating evolution regions massive moving through dense (nH = 3000 cm −3 ), uniform with velocities ranging from 4 16 km s −1 .T he Hii morphology strongly affected motion, as expected, but bubble also very aspherical birth, even for lowest space velocity considered. Wind do not fill their (we find filling factors 10–20 per cent), at least main sequence star mass M� ∼ 30 . Furthermore, supersonic bow shock does significantly trap ionization front. X-ray soft, faint, comes mainly turbulent mixing layer region. radiates <1 cent its energy in X-rays; it loses most cooler photoionized gas. Comparison 120 shows that dynamical age 0.4 Myr motion 4k m allowed, implying source unlikely be runaway more likely formed situ. region’s youth, apparent isolation other or B makes interesting studies formation initial functions.