Formation of Globular Clusters in Galaxy Mergers
نویسندگان
چکیده
We present a high-resolution simulation of globular cluster formation in a galaxy merger. For the first time in such a simulation, individual star clusters are directly identified and followed on their orbits. We quantitatively compare star formation in the merger to that in the unperturbed galaxies. The merging galaxies show a strong starburst, in sharp contrast to their isolated progenitors. Most star clusters form in the tidal tails. With a mass range of 5 × 10–5 × 10M⊙, they are identified as globular clusters. The merger remnant is an elliptical galaxy. Clusters with different mass or age have different radial distributions in the galaxy. The cluster mass spectrum appears to be roughly log-normal. Our results show that the high specific frequency and bimodal distribution of metallicity observed in elliptical galaxies are natural products of gas-rich mergers, supporting a merger origin for the ellipticals and their globular cluster systems. Subject headings: galaxy: interactions — galaxy: globular clusters — galaxy: star formation — galaxy: evolution — star clusters: formation
منابع مشابه
Formation Scenarios for Globular Clusters and Their Host Galaxies
This review focuses on how galaxies and their globular cluster systems form. I first discuss the now fairly convincing evidence that some globular clusters form in galaxy starbursts/mergers. One way these observations are valuable is they place important constraints on the physics of the formation of globular clusters. Moreover, it is natural to associate the typically metal-rich clusters formi...
متن کاملThe Formation and Evolution of Star Clusters and Galaxies
This paper addresses the questions of what we have learned about how and when dense star clusters form, and what studies of star clusters have revealed about galaxy formation and evolution. One important observation is that globular clusters are observed to form in galaxy mergers and starbursts in the local universe, which both provides constraints on models of globular cluster formation, and s...
متن کاملHigh-resolution simulations of galaxy mergers: Resolving globular cluster formation
Massive star clusters observed in galaxy mergers are often suggested to be progenitors of globular clusters. To study this hypothesis, we performed the highest resolution simulation of a gas-rich galaxy merger so far. The formation of massive star clusters of 10 to 10 M⊙, triggered by the galaxy interaction, is directly resolved in this model. We show that these clusters are tightly bound struc...
متن کاملDamp Mergers: Recent Gaseous Mergers without Significant Globular Cluster Formation?
Here we test the idea that new globular clusters (GCs) are formed in the same gaseous (“wet”) mergers or interactions that give rise to the young stellar populations seen in the central regions of many early-type galaxies. We compare mean GC colors with the age of the central galaxy starburst. The red GC subpopulation reveals remarkably constant mean colors independent of galaxy age. A scenario...
متن کاملGlobular Cluster Formation in Mergers
Mergers of gas-rich galaxies lead to gravitationally driven increases in gas pressure that can trigger intense bursts of star and cluster formation. Although star formation itself is clustered, most newborn stellar aggregates are unbound associations and disperse. Gravitationally bound star clusters that survive for at least 10–20 internal crossing times (∼20–40 Myr) are relatively rare and see...
متن کامل