The Origin of the Virgo Stellar Over-density: A Tidal Debris from the Sagittarius Dwarf Galaxy?

Martínez-Delgado, D.; Peñarubia, J.; Jurić, M.; Alfaro, E. J.
From Stars to Galaxies: Building the Pieces to Build Up the Universe. ASP Conference Series, Vol. 374, proceedings of the conference held 16-20 October 2006 at Istituto Veneto di Scienze, Lettere ed Arti, Venice, Italy. Edited by Antonella Vallenari, Rosaria Tantalo, Laura Portinari, and Alessia Moretti., p.195


The recently discovered Virgo stellar over-density, which expands perpendicularly to the Galactic disk plane (7< Z < 15 kpc, R˜ 7 kpc), is the largest clump of tidal debris ever detected in the outer halo and is likely related with the accretion of a nearby dwarf galaxy by the Milky Way. We carry out N-body simulations of the Sagittarius stream to show that this giant stellar over-density is a confirmation of theoretical model predictions for the leading tail of the Sagittarius stream to cross the Milky Way plane in the Solar neighborhood.