FOF (mdr1.fof)

The table has 458805088 rows, 37 columns.

Description

Main Friends-of-Friends catalogue for all available snapshots, level 0 (relative linking length 0.17);
fofid = (snapnum * 10 + level)*108 +(rank in FOF-file)

Attribution

In order to properly acknowledge our efforts, we request the following paragraph to be included in the "Acknowledgements" section of any publication which makes use of the simulation data above via the CosmoSim or MultiDark database:

Acknowledgements – Database

The CosmoSim database used in this paper is a service by the Leibniz-Institute for Astrophysics Potsdam (AIP). The MultiDark database was developed in cooperation with the Spanish MultiDark Consolider Project CSD2009-00064.

Acknowledgements – Simulations

The authors gratefully acknowledge the Gauss Centre for Supercomputing e.V. (www.gauss-centre.eu) and the Partnership for Advanced Supercomputing in Europe (PRACE, www.prace-ri.eu) for funding the MultiDark simulation project by providing computing time on the GCS Supercomputer SuperMUC at Leibniz Supercomputing Centre (LRZ, www.lrz.de). The Bolshoi simulations have been performed within the Bolshoi project of the University of California High-Performance AstroComputing Center (UC-HiPACC) and were run at the NASA Ames Research Center.

More information can be found on the credit page.

Columns

Name Type UCD Unit Description
fofid long meta.id
meta.main

unique id for FOF-group

snapnum short time.epoch

number of snapshot; look into redshifts-table to find the corresponding redshift

level short

level of substructure, indicates the different linking lengths

ninfile int meta.id

line number of FOF-group in original catalogue file (= rank in file)

x double pos.cartesian.x h-1.Mpc

comoving position, x-component

y double pos.cartesian.y h-1.Mpc

comoving position, y-component

z double pos.cartesian.z h-1.Mpc

comoving position, z-component

vx double phys.veloc
pos.cartesian.x
km.s-1

peculiar velocity, x-component

vy double phys.veloc
pos.cartesian.y
km.s-1

peculiar velocity, y-component

vz double phys.veloc
pos.cartesian.z
km.s-1

peculiar velocity, z-component

np int meta.number

number of particles inside the FOF group ("halo")

mass double phys.mass h-1.solMass

total mass of the FOF group

size double phys.size.radius h-1.Mpc

"radius" of the FOF group, if it were a sphere, computed based on the volume

disp double phys.dispMeasure h-1.Mpc

dispersion

disp_v double phys.veloc.dispersion km.s-1

velocity dispersion

delta double phys.density
arith.ratio

overdensity (mass/volume) in terms of mean background density rho_b

spin double

spin parameter (Gottlöber & Yepes 2007, ApJ 664, 117)

angmom_x double phys.angMomentum
pos.cartesian.x
h-2.solMass.Mpc.km.s-1

angular momentum, x-component

angmom_y double phys.angMomentum
pos.cartesian.y
h-2.solMass.Mpc.km.s-1

angular momentum, y-component

angmom_z double phys.angMomentum
pos.cartesian.z
h-2.solMass.Mpc.km.s-1

angular momentum, z-component

angmom double phys.angMomentum h-2.solMass.Mpc.km.s-1

absolute value of angular momentum

axis1 double

major axis of the ellipsoidal shape, not normalized

axis2 double

intermediate axis of the ellipsoidal shape, not normalized

axis3 double

minor axis of the ellipsoidal shape, not normalized

axis1_x double

direction of major axis, unit eigenvector of the inertia tensor, x-component

axis1_y double

direction of major axis, y-component

axis1_z double

direction of major axis, z-component

axis2_x double

direction of intermediate axis, unit eigenvector of the inertia tensor, x-component

axis2_y double

direction of intermediate axis, y-component

axis2_z double

direction of intermediate axis, z-component

axis3_x double

direction of minor axis, unit eigenvector of the inertia tensor, x-component

axis3_y double

direction of minor axis, y-component

axis3_z double

direction of minor axis, z-component

ix int pos.cartesian.x

spatial index, x-direction

iy int pos.cartesian.y

spatial index, y-direction

iz int pos.cartesian.z

spatial index, z-direction

phkey int

Peano-Hilbert key