This table contains the FoF group catalogues for all 64 snapshots of the Millennium Run (MR).
Subhalos identified within in these groups are listed in the
Subhalo table.
| column | type | UCD | unit | description |
|---|
| FoFID |
long |
meta.id;meta.main |
|
The ID of this FoF group, unique within the full simulation.
|
| NumSubgroups |
int |
meta.number |
|
Number of subhalos in this FoF group.
|
| FirstSubhaloID |
long |
meta.id.assoc |
|
The unique ID of the most massive subhalo in this FoF
group. This corresponds to an entry in the Subhalo table.
|
| np |
int |
meta.number |
|
Number of simulation particles in this FoF group.
|
| SnapNum |
int |
time |
|
The snapshot number where this FoF group was identified.
|
| Redshift |
float |
time |
|
The redshift of the snapshot to which this FoF group belongs.
|
| x |
float |
pos.cartesian.x |
1/h Mpc |
x-component position
|
| y |
float |
pos.cartesian.y |
1/h Mpc |
y-component position
|
| z |
float |
pos.cartesian.z |
1/h Mpc |
z-component position
|
| m_Mean200 |
float |
phys.mass |
1010 Msun/h |
The mass within the radius where the halo has an overdensity 200 times the mean density of the simulation.
|
| m_Crit200 |
float |
phys.mass |
1010 Msun/h |
The mass within the radius where the halo has an overdensity 200 times the critical density of the simulation.
|
| m_TopHat |
float |
phys.mass |
1010 Msun/h |
The mass within the radius where the halo has an overdensity corresponding to the value at virialisation in the top-hat collapse model for this cosmology.
|
| r_Mean200 |
float |
phys.radius |
Mpc/h |
The radius within which the halo has an overdensity 200 times the mean density of the simulation.
|
| r_Crit200 |
float |
phys.radius |
Mpc/h |
The radius within which the halo has an overdensity 200 times the critical density of the simulation.
|
| r_TopHat |
float |
phys.radius |
Mpc/h |
The mass radius within which the halo has an overdensity corresponding to the value at virialisation in the top-hat collapse model for this cosmology.
|
| phKey |
integer |
|
|
Peano-Hilbert key, (bits=8), for position in 500/h Mpc
box. See the text on spatial indexes.
|
| zIndex |
integer |
|
|
The "bit-interleaved" or "Z-curve" index, corresponding to this halo's position. Same resolution as phKey.
See the text on spatial indexes.
|
| ix |
integer |
pos.cartesian.x |
|
Zone index along x-direction, based on 50 bins. See the text on spatial indexes.
|
| iy |
integer |
pos.cartesian.y |
|
Zone index along y-direction, based on 50 bins. See the text on spatial indexes.
|
| iz |
integer |
pos.cartesian.y |
|
Zone index along z-direction, based on 50 bins. See the text on spatial indexes.
|
| random |
float |
|
|
A random number between 0 and 1000000. See the section on
random sampling.
|
