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| Paper: |
The Red Sequence of High-Redshift Clusters: A Comparison with Cosmological Galaxy Formation Models |
| Volume: |
399, Panoramic Views of Galaxy Formation and Evolution |
| Page: |
348 |
| Authors: |
Menci, N. |
| Abstract: |
We compare the results from a state-of-the-art semi-analytic model of galaxy formation with spectroscopic observations of the distant galaxy clusters observed in the range 1 ≤ z ≤ 1.5. In our model we find that i) a well-defined, narrow red sequence (RS) is obtained already by z ≈ 1.2; this is more populated than the field RS analogously to what observed and predicted at z = 0; ii) the predicted RS colors and width have average values of 1 and 0.15, respectively, with a cluster-to-cluster variance. The width of the RS of cluster galaxy is 5-10 times lower than the corresponding field value; iii) The predicted distribution of stellar ages of RS galaxies at z = 1.2 are peaked at the value τ = 3.7 Gyr for both cluster and field; however, for the latter the distribution is significantly skewed toward lower ages. When compared with observations, the above findings show an overall consistency, although the average value ≈ 0.07 of the observed cluster RS width at z ≈ 1.2 is smaller than the corresponding model central value. We discuss the physical origin and the significance of the above results in the framework of cosmological galaxy formation. |
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