Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2010-01-06
Astrophysical Journal 710 (2010) 51-63
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
Accepted for publication in ApJ, vol. 710, February 2010
Scientific paper
10.1088/0004-637X/710/1/51
Two recent empirical developments in the study of extragalactic globular cluster (GC) populations are the color-magnitude relation of the blue GCs (the "blue tilt") and the nonlinearity of the dependence of optical GC colors on metallicity. The color-magnitude relation, interpreted as a mass-metallicity relation, is thought to be a consequence of self-enrichment. Nonlinear color-metallicity relations have been shown to produce bimodal color distributions from unimodal metallicity distributions. We simulate GC populations including both a mass-metallicity scaling relation and nonlinear color-metallicity relations motivated by theory and observations. Depending on the assumed range of metallicities and the width of the GC luminosity function (GCLF), we find that the simulated populations can have bimodal color distributions with a "blue tilt" similar to observations, even though the metallicity distribution appears unimodal. The models that produce these features have the relatively high mean GC metallicities and nearly equal blue and red peaks characteristic of giant elliptical galaxies. The blue tilt is less apparent in the models with metallicities typical of dwarf ellipticals; the narrower GCLF in these galaxies has an even bigger effect in reducing the significance of their color-magnitude slopes. We critically examine the evidence for nonlinearity versus bimodal metallicities as explanations for the characteristic double-peaked color histograms of giant ellipticals and conclude that the question remains open. We discuss the prospects for further theoretical and observational progress in constraining the models presented here and for uncovering the true metallicity distributions of extragalactic globular cluster systems.
Blakeslee John P.
Cantiello Michele
Peng Eric West
No associations
LandOfFree
The Mass-Metallicity Relation of Globular Clusters in the Context of Nonlinear Color-Metallicty Relations does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The Mass-Metallicity Relation of Globular Clusters in the Context of Nonlinear Color-Metallicty Relations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Mass-Metallicity Relation of Globular Clusters in the Context of Nonlinear Color-Metallicty Relations will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-372933