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Orbits_pre processing

Page history last edited by pierluigi.cerulo@gmail.com 9 years, 3 months ago

Title: Quantifying the Effect of Pre-processing in the Build-up of the Red Sequence in Galaxy Clusters


Motivation: The red sequence is one of the most notable and easiest to identify observational features of galaxy clusters. Although it has long been studied and used in large campaigns for cluster detection at all redshifts, its evolution is still poorly understood and much debated. Simulations struggle to reproduce the properties of the red sequence in clusters at redshifts z>1, while the little size of high-redshift cluster samples has led to a significant disagreement between observational studies. In particular, some authors show that the the red sequence in distant clusters is truncated at the faint end, suggesting that the least massive galaxies ceased star formation at later epochs compared to the highest mass galaxies. However, this conclusion is contradicted by a number of studies which detect no deficit at the faint end of the red sequence in high redshift galaxy clusters, suggesting that the build-up of the red sequence took place at early epochs (z>2) and on short timescales.


Aim: The aim of this project is to analyse the properties of the red sequence in the cluster 00019 as a function of time distinguishing between the galaxies which reside in the cluster and those which are part of satellite groups accreted on to the cluster (pre-processed galaxies). In particular, the project aims to explore what range of luminosities the pre-processed galaxies occupy on the cluster red sequence and how do they contribute to the build-up of the faint end. The available data for z~1 and z~0 clusters will be used for comparisons with observations.


Methodology and working plan:

1) Use available galaxy catalogues to identify cluster and group galaxies at each simulation snapshot;

2) model the red sequence of cluster and group galaxies at each simulation snapshot;

3) study the luminosity distribution of red sequence galaxies in the cluster and in groups at each simulation snapshot and compare with observations;

4) identify galaxies which are cluster members but were previously in an accreted satellite group;

5 ) measure fraction of pre-processed galaxies in the cluster at each simulation snapshot;

6 ) study the luminosity distribution of pre-processed galaxies at each simulation snapshot.


Please provide comments and let me know if you are interested in participating.





plot_test_red_number_counts_z_eq_1.0.pdf plot_test_red_number_counts_z_eq_0.5.pdf plot_test_red_number_counts_z_eq_0.04.pdf

plot_find_cl19_rich_halos_z_eq_2.2.pdf plot_find_cl19_rich_halos_z_eq_1.5.pdf plot_find_cl19_rich_halos_z_eq_1.0.pdf plot_find_cl19_rich_halos_z_eq_0.5.pdf

plot_test_red_fraction_z_eq_2.2.pdf plot_test_red_fraction_z_eq_1.5.pdf plot_test_red_fraction_z_eq_1.0.pdf plot_test_red_fraction_z_eq_0.5.pdf plot_test_red_fraction_z_eq_0.04.pdf

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