FOFMtree (mdr1.fofmtree)

The table has 181523200 rows, 21 columns.


Merger trees for top level FOF groups (level=0) with > 2 * 1012 Msun/h from redshift 0. Substructures are not taken into account.


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. ( and the Partnership for Advanced Supercomputing in Europe (PRACE, for funding the MultiDark simulation project by providing computing time on the GCS Supercomputer SuperMUC at Leibniz Supercomputing Centre (LRZ, 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.


Name Type UCD Unit Description
foftreeid long

unique id for FOF-group = treeRootId + rank in merger tree (depth first order)

fofid long

corresponding id of this FOF group in the FOF table

treesnapnum short time.epoch

subsequent number of snapshot used for creating the merger tree, not the same number as in FOF table

descendantid long

fofTreeId for direct descendant (to which the FOF group will merge in the next timestep)

lastprogid long

fofTreeId of last progenitor in depth-first order

mainleafid long

fofTreeId of last leaf on main branch, which is defined by the most massive progenitors

treerootid long

root in merger tree

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

comoving velocity, x-component

vy double phys.veloc

comoving velocity, y-component

vz double phys.veloc

comoving velocity, z-component

np int meta.number

number of particles inside the FOF group

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

spin double

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

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