The Formation of Intracluster Light

CWRU collaborators: John Feldmeier, Heather Morrison, Paul Harding CWRU students: Cameron McBride (Pittsburgh), Nathan Kaib (Washington), Steve Rodney (Hawaii) When did it form? How did it form? Early cluster collapse or late accretion? Low luminosity galaxies or high? Coherent substructure or diffuse ICL? Metallicity and kinematic properties? Correlations with cluster properties? Deep imaging of Abell 1914 from Feldmeier etal 2004 Theoretical work has largely focused on tidal stripping of individual galaxies in a fixed potential well (eg Merritt 1983; Richstone & Malamuth 1983; Moore etal 1996; Calcaneo-Roldan etal 2000) and ignored two important effects: preprocessing in groups , and heating by substructure (Gnedin 2003). Full cosmologically-motivated simulations are needed to study the phenomenon (eg Dubinski etal 2000; Napolitano etal 2003; Mihos etal 2004 ).

Numerical Simulations I   (from Feldmeier etal 2004, after Dubinski etal 2000) Cluster Evolution: Cluster Variance:

Numerical Simulations II (Mihos etal 2004) We use a similar technique to Dubinski (2000): LCDM cosmological simulation ID clusters at z=0 (M ~ 6x1013 Msun; sigma ~ 450 km/s) track back to subhalos at high redshift (z=2) substitute individual galaxy models (to ~ 1/3 MMW) high mass halos -- use HOD scheme N ~ M 0.7 (eg Berlind & Weinberg 2002) scale size, velocity of galaxies w/ mass so that S's stay on TF; scale E's similarly evolve (collisionlessly) to z=0 We see significant kinematic and spatial substructure at early times; at late times much is mixed/heated away. Shallow stretch "Deep Imaging"

However, significant substructure remains even at z=0 at low surface brightnesses: z=0 morphology z=0 position-velocity diagram