Title: The morphology of M17-UC1 - The first candidate of a disk surrounding a hyper-compact HII region Authors: M. Nielbock, R. Chini, V. H. Hoffmeister, C. M. Scheyda, J. Steinacker, D. Nuernberger, R. Siebenmorgen, J. Berndt, E. Kovacevic, I. Stefanovic, J. Winter (revised v3)
We investigate the morphology and the evolutionary stage of the hyper-compact HII region M17-UC1 using observations at infrared wavelengths and NIR radiative transfer modelling. The object was for the first time resolved into two emission areas separated by a dark lane reminiscent of an obscuring silhouette of a circumstellar disk. The observational data as well as model calculations so far suggest that M17-UC1 is surrounded by a disk of cool dust. This first direct detection of a circumstellar disk candidate around a hyper-compact HII region is in agreement with the expectations of the disk accretion model for high-mass star formation.