AAS 205th Meeting, 9-13 January 2005
Session 31 Evolution of Ellipticals and Dark Matter Halos
Oral, Monday, January 10, 2005, 10:00-11:30am, California

Previous   |   Session 31   |   Next

[31.08] Elliptical Galaxy Globular Cluster Systems: The Origin Of Color Bimodality

K.M. Ashman, T.M. Walker (University of Missouri--KC), S.E. Zepf (Michigan State University)

It is well-established that the globular cluster systems of many ellipticals exhibit color bimodality. The origin of this bimodality, however, is still a topic of debate. One suggestion is that such color distributions are a result of elliptical galaxies forming through dissipationless hierarchical clustering. In this picture, the red population of globular clusters in such systems is primarily contributed by a massive "seed" object around which the elliptical forms, whereas the blue clusters are associated with accreted protogalactic fragments (or dwarf galaxies). Our primary goal in this study is to establish the likelihood that such a model produces color distributions like those observed. Using Monte Carlo simulations, we confirm the finding of previous authors that dissipationless hierarchical clustering can reproduce empirical distributions. However, our main conclusion is that the frequency with which such a model reproduces bimodal color distributions is much lower than observed. Thus this model is not a viable one for the origin of the majority of globular cluster systems around ellipticals.

This work was supported in part by NSF grant AST-0406876

The author(s) of this abstract have provided an email address for comments about the abstract: ashmank@umkc.edu

Previous   |   Session 31   |   Next

Bulletin of the American Astronomical Society, 36 5
© 2004. The American Astronomical Society.