The Virgo stellar over-density Mapping the infall of the Sag(6)

The recently discovered Virgo stellar over-density, which expands over \~1000deg^2 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 accre

12Mart´ nez-Delgadoet

al.

Fig.5.—Twodi erent3-dimensionalprojections(topandbottomrows)oftheSagittariustidalstreammodelscomputedfor

anoblatehaloqh=0.8(leftcolumn)andaprolateqh=1.4halo(rightcolumn).Thecolumndensityofsimulationparticlesisrepresentedbyrainbowcolor-map,withtheredbeingtheareasofhighest,andbluethelowestdensity.Over-plottedonthecolumndensitymapasblackdotsarethesimulationparticlesthemselves.ThecoreofSgrdwarfisclearlyvisibleasadense,darkregion,duetothehighdensityofsimulationparticleswhicharestillgravitationallyboundtothedwarf’score.TheoriginofthecoordinatesystemaxesistheGalacticcenter,withtheredaxis(X)pointingtowardstheSun(yellowcircle),theblueaxis(Z)pointingtowardsthenorthGalacticpole.TheregioninwhichJuri´cetal.(2006)detecttheVirgooverdensityismarkedbythewhitewire-framebox.Thebluewire-framemarksthelocationofVirgoStellarStreamasreportedbyDu auetal.(2006).

.