High resolution near-infrared interferometric imaging of the ultracompact H II region K3-50 A S. Kraus(1), Y. Y. Balega(2), K.-H. Hofmann(1), T. Preibisch(1), G. Weigelt(1 ) MPIfR Abstract (1) Max-Planck-Institut fur Radioastronomie, Bonn, Germany Ё (2) Sp ecial Astrophysical Observatory, Karachai-Cherkesia, Russia Only for the 10 µm source STHO 1 we can see no counterpart in our K -band image. ... It is also interesting to compare the K -band and N -band fluxes of the sources. ... 2003). ...

... Ultraluminous X-ray sources (ULXs) are located in external galaxies, their X-ray luminosities (10 39 - 10 41 erg/s) are thousand times greater than those of brightest black holes in the Galaxy. ULXs may be supercritical accretion disks around black holes of stellar masses (~10 Solar masses) like that in SS433, or they may be a hypothetical intermediate-mass black holes (hundreds - thousands Solar masses) with standard accretion disks. ... 2) The ULX progenitors were ejected from the star clusters. ...