Resolving Extragalactic Nuclei with the VLT

Abstract

Recent high spatial resolution studies of the Galactic Center with the ES-O NTT have demonstrated the presence of different stellar populations in the central cluster of the Galaxy. These studies have also allowed us to derive the core radius of the central stellar cluster and have revealed for the first time a near-infrared source at the radio position of Sgr A*, a prime candidate for a supermassive black hole. In the case of the Seyfert 1 galaxy NGC 7469 (D = 66Mpc), similar high resolution near-infrared imaging has revealed a powerful circumnuclear starburst ring which is responsible for 2/3 of the bolometric luminosity of the entire galaxy.

With the high spatial resolution of the ESO 8m dishes (60 mas at 2.2μm) and the VLTI (2.4 mas at 2.2μm on a 200 m baseline) these kinds of studies can be extended to extragalactic nuclei. In nearby galaxies (D ≤ 10Mpc) we will be able to resolve the nuclei into individual stars or star clusters, perhaps revealing central very massive objects. In addition, probing the near-nuclear regions of active galaxies at cosmologically interesting distances will be made possible via the VLT(I) resolution.

In this contribution we present simulated images of these nuclei based on our current knowledge of the structure of the Galactic Center and nearby galaxies.