Some globular clusters may be leftovers from snacking galaxies

According to the hierarchical theory of galaxy formation, galaxies have grown larger over time by consuming smaller dwarf galaxies and star clusters. And sometimes, it seems that the unfortunate prey is not swallowed whole but instead is munched like a peach, stripped of its outer layers to leave behind only the pit. New findings by Paul Martini and Luis Ho hint at an important yet puzzling connection between the largest globular clusters and the smallest dwarf galaxies. For their investigation, the team studied 14 globular clusters in the large elliptical galaxy Centaurus A (NGC 5128) using the 6.5-meter-diameter Magellan Clay telescope at Carnegie’s Las Campanas Observatory, Chile. “The essence of our findings is that these 14 globulars are 10 times more massive than the smaller globulars in our neighborhood, and whatever process makes them can produce some really huge objects — they begin to overlap with the smallest galaxies,” says Martini. Martini and Ho reported their results in the July 20, 2004, issue of The Astrophysical Journal.