These latest Hubble observations of the Sombrero galaxy indicate only a tiny fraction of older, metal-poor stars in the halo, plus an unexpected abundance of metal-rich stars. Past major galaxy mergers are a possible explanation, though the stately Sombrero shows none of the messy evidence of a recent merger of massive galaxies.
Click here for original story, Beyond the brim, Sombrero Galaxy’s halo suggests turbulent past
Source: ScienceDaily