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