SIMBAD references

2008ApJ...682L..73S - Astrophys. J., 682, L73-L76 (2008/August-1)

Connecting substructure in galaxy cluster cores at z = 0.2 with cluster assembly histories.


Abstract (from CDS):

We use semianalytic models of structure formation to interpret gravitational lensing measurements of substructure in galaxy cluster cores (R≤250 h–1 kpc) at z=0.2. The dynamic range of the lensing-based substructure fraction measurements is well matched to the theoretical predictions, both spanning fsub∼0.05-0.65. The structure formation model predicts that fsub is correlated with cluster assembly history. We use simple fitting formulae to parameterize the predicted correlations: Δ909090log(fsub) and Δ505050log(fsub), where Δ90 and Δ50 are the predicted lookback times from z=0.2 to when each theoretical cluster had acquired 90% and 50%, respectively, of the mass it had at z=0.2. The best-fit parameter values are α90=-1.34±0.79 Gyr, τ90=0.31±0.56 Gyr and α50=-2.77±1.66 Gyr, τ50=0.99±1.18 Gyr. Therefore, (1) observed clusters with fsub≲0.1 (e.g., A383, A1835) are interpreted, on average, to have formed at z≳0.8 and to have suffered ≤10% mass growth since z≃0.4, and (2) observed clusters with fsub≳0.4 (e.g., A68, A773) are interpreted as, on average, forming since z≃0.4 and suffering >10% mass growth in the ∼500 Myr preceding z=0.2, i.e., since z=0.25. In summary, observational measurements of fsub can be combined with structure formation models to estimate the age and assembly history of observed clusters. The ability to ``age date'' approximately clusters in this way has numerous applications to the large samples of clusters that are becoming available.

Abstract Copyright:

Journal keyword(s): Cosmology: Observations - Cosmology: Theory - Galaxies: Clusters: General - galaxies: clusters: individual (A68) - Galaxies: Clusters: Individual: Alphanumeric: A209 - Galaxies: Clusters: Individual: Alphanumeric: A267 - galaxies: clusters: individual (A383) - Galaxies: Clusters: Individual: Alphanumeric: A773 - Galaxies: Clusters: Individual: Alphanumeric: A963 - galaxies: clusters: individual (A1763) - Galaxies: Clusters: Individual: Alphanumeric: A1835 - Galaxies: Clusters: Individual: Alphanumeric: A2218 - Galaxies: Clusters: Individual: Alphanumeric: A2219 - Cosmology: Gravitational Lensing

Simbad objects: 10

goto Full paper

goto View the references in ADS

To bookmark this query, right click on this link: simbad:2008ApJ...682L..73S and select 'bookmark this link' or equivalent in the popup menu


© Université de Strasbourg/CNRS

    • Contact