This table contains the catalogue of halos used to construct the
merger trees used in the Bower et al (2006) galaxy formation
model. Each DHalo is a collection of SubFind subhalos grouped together to
make a halo. Note that the objects referred to as subhalos here
(SubFind groups) are equivalent to the objects listed in the MHalo table.
| column | type | UCD | unit | description |
|---|
| DHaloID |
long |
meta.id;meta.main |
|
The ID of this DHalo, unique within the full simulation.
|
| DescendantId |
long |
meta.id.assoc |
|
The ID of the descendant of this DHalo in the merger tree.
|
| LastProgenitorId |
long |
meta.id.assoc |
|
Indicator of the last progenitor in the DHalo merger tree
rooted in this DHalo.
All DHalos with id between ID
and LastProgenitorId form the merger tree rooted in this
DHalo. |
| TreeId |
long |
meta.id.parent |
|
The unique id of the DHalo merger tree to which this DHalo belongs.
|
| FirstSubhaloID |
long |
meta.id.assoc |
|
The unique id of the most massive subhalo in this DHalo
|
| np |
int |
meta.number |
|
Number of simulation particles in this DHalo. This is
equal to the total number of particles in the constituent
subhalos of the DHalo.
|
| NSubhalos |
int |
meta.number |
|
Number of subhalos in this DHalo.
|
| SnapNum |
int |
time |
|
The snapshot number where this DHalo was identified.
|
| Redshift |
float |
time |
|
The redshift of the snapshot to which this DHalo belongs.
|
| FirstProgenitorID |
long |
meta.id.assoc |
|
The ID of the most massive progenitor of the DHalo
|
| EndMainBranchID |
long |
meta.id.assoc |
|
The ID of the halo at the end of the main progenitor branch of this halo.
|
| 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.
|
