VEGAS: VST survey of Early-type GAlaxieS


VEGAS is a deep multi-band (u, g, r, i) imaging survey of early-type galaxies in the Southern hemisphere carried out with VLT Survey Telescope (VST). The VST is a 2.6m wide-field optical survey telescope, located at the European Southern Observatory (ESO) Cerro Paranal Observatory (Chile).

VEGAS is based on the Guaranteed Time Observation (GTO) assigned at the INAF (Italian National Institute for Astrophysics).

Observations started on October 2011, under the leadership of Massimo Capaccioli. VEGAS has been approved as INAF GTO project for the period  2016-2021 (P.I. E. Iodice).

The large field-of-view (FOV) of the OmegaCam mounted on VST (1 deg2 matched by 0.21 arcsec wide pixels), together with its high efficiency and spatial resolution (typically better than 1 arcsec) allows us to map, with a reasonable integration time, the surface brightness of a galaxy out to out to 8 − 10Re and down to μg 31 mag/arcsec2.

We plan to reach these limits for a large sample of early-type galaxies in different environments, including giant cD galaxies in the core of clusters. The main scientific goals of this survey are to study galaxy structure, including the diffuse light component, substructures and the low-surface brightness features including tidal tails, stellar streams and shells.

The design of VEGAS will allow us to interpret these features statistically in the context of hierarchical assembly in a ΛCDM universe with the aid of cosmological simulations.