Ionizing feedback from massive stars in massive clusters – II. Disruption of bound clusters by photoionization

摘要: We present a smoothed particle hydrodynamics parameter study of the dynamical effect photoionization from O-type stars on star-forming clouds range masses and sizes during time window before supernovae explode. Our model all have same degree turbulent support initially, ratio kinetic energy to gravitational potential being set Ekin/|Epot|= 0.7. allow form effects ionizing radiation massive or clusters born within them. find that dense filamentary structures accretion flows limit quantities gas can be ionized, particularly in higher density clusters. More importantly, escape velocities our more (106 M⊙) prevent H ii regions sweeping up expelling significant gas, so most are largely dynamically unaffected by feedback. However, feedback has profound lower 104 105 M⊙ study, creating vast evacuated bubbles tens per cent neutral 3-Myr time-scale first expected detonate, resulting highly porous both photons supernova ejecta.