Winds Driven by Massive Star Clusters

Here I discuss the X-ray emission resulting from the interaction of star cluster winds with the surrounding medium. I demonstrate that X-ray emission from the free wind region dominates the total bubble X-ray luminosity if the central star cluster is sufficiently young, massive and compact. I also prove that strong radiative cooling is a crucial ingredient which defines the physical properties and observational manifestations of gaseous outflows generated within such clusters. It may modify drastically the distribution of temperature if the rate of injected energy approaches a critical value. I also show that the stationary wind solution does not exist whenever the energy radiated away at the star cluster center exceeds 30% of the energy deposition rate. This implies that stationary star cluster winds may evolve either in the quasi-adiabatic or in the strongly radiative regimes. I then compare our model to the winds from Arches cluster and NGC4303 central cluster and demonstrate that Arches cluster wind evolves in a quasi-adiabatic regime whereas the NGC4303 cluster wind seems to be strongly affected by the radiative cooling.