We use 3D hydrodynamical models to investigate the effects of massive star feedback from winds and supernovae on inhomogeneous molecular material left over from the formation of a massive stellar cluster. We simulate the interaction of the mechanical energy input from a cluster with 3 O-stars into a giant molecular cloud (GMC) clump containing 3240 M of molecular material within a 4 pc radius. The cluster wind blows out of the molecular clump along low-density channels, into which denser clump material is entrained. We find that the densest molecular regions are surprisingly resistant to ablation by the cluster wind, in part due to shielding by other dense regions closer to the cluster. Nonetheless, molecular material is gradually removed by the cluster wind during which mass-loading factors in excess of several 100 are obtained. Because the clump is very porous, 60 − 75 per cent of the injected wind energy escapes the simulation domain, with the difference being radiated. After 4.4 Myr, the massive stars in our simulation begin to explode as supernovae. The highly structured environment into which the SN energy is released allows even weaker coupling to the remaining dense material and practically all of the SN energy reaches the wider environment. The molecular material is almost completely dispersed and destroyed after 6 Myr. The escape fraction of ionizing radiation is estimated to be about 50 per cent during the first 4 Myr of the cluster's life. A similar model with a larger and more massive GMC clump reveals the same general picture, though more time is needed for it to be destroyed.

We present high‐resolution H i data obtained using the Australia Telescope Compact Array to resolve the near/far distance ambiguities towards a sample of compact H ii regions from the Red MSX Source (RMS) survey. The high‐resolution data are complemented with lower resolution archival H i data extracted from the Southern and Very Large Array (VLA) Galactic Plane surveys. We resolve the distance ambiguity for nearly all of the 105 sources where the continuum was strong enough to allow analysis of the H i absorption line structure. This represents another step in the determination of distances to the total RMS sample, which with over 1000 massive young stellar objects and compact H ii regions is the largest and most complete sample of its kind. The full sample will allow the distribution of massive star formation in the Galaxy to be examined.

The X-ray emission from a simulated massive stellar cluster is investigated. The emission is calculated from a 3D hydrodynamical model which incorporates the mechanical feedback from the stellar winds of 3 O-stars embedded in a giant molecular cloud (GMC) clump containing 3240 M ⊙ of molecular material within a 4 pc radius. A simple prescription for the evolution of the stars is used, with the first supernova explosion at t = 4.4 Myrs. We find that the presence of the GMC clump causes shortlived attenuation effects on the X-ray emission of the cluster. However, once most of the material has been ablated away by the winds the remaining dense clumps do not have a noticable effect on the attenuation compared with the assumed interstellar medium (ISM) column. We determine the evolution of the cluster X-ray luminosity, L X , and spectra, and generate synthetic images. The intrinsic X-ray luminosity drops from nearly 10 34 ergs s −1 while the winds are 'bottled up', to a near constant value of 1.7×10 32 ergs s −1 between t = 1-4 Myrs. L X reduces slightly during each star's red supergiant (RSG) stage due to the depressurization of the hot gas. However, L X increases to ≈ 10 34 ergs s −1 during each star's Wolf-Rayet (WR) stage. The X-ray luminosity is enhanced by 2-3 orders of magnitude to ∼ 10 37 ergs s −1 for at least 4600 yrs after each supernova (SN) explosion, at which time the blast wave leaves the grid and the X-ray luminosity drops. The X-ray luminosity of our simulation is generally considerably fainter than predicted from spherically-symmetric bubble models, due to the leakage of hot gas material through gaps in the outer shell. This process reduces the pressure within our simulation and thus the X-ray emission. However, the X-ray luminosities and temperatures which we obtain are comparable to similarly powerful massive young clusters.

Abstract. We present results from a survey of the properties of the central black holes in nearby AGN. This shows that AGN radiating near Eddington are on average less massive now than at z ∼ 1. Keywords. galaxies: active; galaxies: nuclei; accretion, accretion disksWe observed the Ca ii triplet lines near 8550Å in a representative sample of ∼ 150 AGN with z < 0.017. These data were used to derive stellar velocity dispersions (e.g., Nelson & Whittle 1995) and hence black hole masses (Tremaine et al. 2002). We derived accretion rates for 107 of these with measured 25 μm fluxes, using mid-infrared luminosity as a proxy for the luminosity of the AGN (cf. luminosity. Only those objects with MBH < 10 6 . 5 M are near or above Eddington.

Abstract.We have constructed three-dimensional hydrodynamical models to simulate the impact of massive star feedback, via winds and SNe, on inhomogeneous molecular material left over from the formation of a massive stellar cluster. We are studying the timescales for the molecular material to be removed from the environment of a massive stellar cluster and the mass and energy fluxes into the wider environment.