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Volume Simulations: Cluster Catalogs from Light Cone Datasets |
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MPA Homepage > Scientific Research > Research Groups > Galaxy Formation > VIRGO > Hubble Volume > Cluster Catalog |
Go to: -Light-cone surveys Data Visualization (images & movies from Numerical Simulation projects)
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Light-cone Surveys Five separate light-cone 'sky' surveys are produced by each run. Their properties are summarized in the following table - Lightcone geometry : LCDM
Lightcone geometry : tCDM
* available for LCDM only. The POW survey is a combination of the PO octant (extending to z=1.46) plus a 16x76 sq deg wedge extending to twice the simulation cube length (6000/h Mpc) using periodic boundaries. The center of the wedge is co-aligned with the x-y diagonal plane in the simulation cube. The surveys are centered at the following locations in the original simulation cube (mapped to 0-1 interval) - larger
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version VS has origin (0,0,0) and uses octants from that location plus the 7 other vertices (periodic replications of the origin) Cluster catalogs derived from a SPHERICAL OVERDENSITY method applied to the light-cone particle data. Cluster lists are found in files of the form grpSO.d$delta_c/$model.$survey.msort$min where
Each file contains cluster information # m zred sigma ip x y z vx vy vz where
In the cluster data sets, survey coordinate systems are defined so that the survey origins are located at
Cluster locations in the ORIGINAL cube volume can be recovered by
Clusters are identified using a spherical overdensity method with the following steps:
Notes:
### LIMITATIONS ### + IPARENT flag | cen_i - cen_j | <= Rvir_i + Rvir_j Note that the center of any cluster cannot lie within the threshold radius
of any cluster other than itself. The catalog files are shortened versions of the original group finder output. The group finder processes planes of cubes in the Z-direction. Separate output files for each Z-slice are produced. These files can be made available upon request. For each slice iz, there are three output files:
The *.base files contain: # M {X Y Z}_c {Vx Vy Vz V}_com
sigma1D R R.5 S.5
{X Y Z}_mb where
Notes:
The *.extra files contain moments of the internal density and velocity:
where Rij = Sum_k (R-R_c)_i (R-R_c)_j / M The *.iparent files contain the integer iparent flag for each cluster. Original text file written by August.E.Evrard. Comments to: Virgo Administrator virgo@mpa-garching.mpg.de |