The halo catalogues are created using the ROCKSTAR halo finder and it contains also information from the Merger Trees outputs.
The halo catalogue tables are written in HDF5 format.
We provide halo catalogues for all 50 Uchuu snapshots.
The number of files per snapshot is ~4000 (total size ~1.5 TB).
Total data set is ~42 TB.
 How to download the data
 Code to read the Halo Catalogue files
 Analysis scripts (examples)
The table below provides the content of all 83 columns in our halo catalogues.
Column# 
Name 
Type 
Unit 
Description 
0 
scale 
float 
scale factor, same as in snapshotredshifts table 

1 
id 
int64 
unique ID for the halo 

2 
desc_scale 
float 
scale factor of the descendant halo, if applicable 

3 
descId 
int64 
ID of the descendant halo, if applicable 

4 
num_prog 
int64 
number of progenitors 

5 
pid 
int64 
ID of least massive host halo (1 if
distinct halo) 

6 
upid 
int64 
ID of most massive host halo (different
from pid when the halo is within two or more larger
halos) 

7 
desc_pid 
int64 
pid
of the descendant halo, if applicable 

8 
phantom 
int64 
flag for phantom halos, nonzero for halos interpolated
across timesteps 

9 
sam_Mvir 
float 
Msun/h 
halo mass, smoothed across accretion history; always
greater than the sum of halo masses of contributing progenitors; only for use
with selected semianalytic models 
10 
Mvir 
float 
Msun/h 
halo mass (within virial radius) 
11 
Rvir 
float 
kpc/h 
halo radius (comoving) 
12 
rs 
float 
kpc/h 
scale radius (comoving) 
13 
vrms 
float 
km/s 
velocity dispersion (physical) 
14 
mmp 
boolean 
flag indicating whether the halo is the most massive
progenitor or not 

15 
scale_of_last_MM 
float 
scale factor of the last major merger (Mass ratio > 0.3) 

16 
vmax 
float 
km/s 
maximum circular velocity (physical) 
17 
x 
float 
Mpc/h 
halo position (comoving) 
18 
y 
float 
Mpc/h 
halo position (comoving) 
19 
z 
float 
Mpc/h 
halo position (comoving) 
20 
vx 
float 
km/s 
halo velocity (physical, peculiar) 
21 
vy 
float 
km/s 
halo velocity (physical, peculiar) 
22 
vz 
float 
km/s 
halo velocity (physical, peculiar) 
23 
Jx 
float 
(Msun/h)* (Mpc/h)* km/s 
halo angular momentum (physical) 
24 
Jy 
float 
(Msun/h)* (Mpc/h)* km/s 
halo angular momentum (physical 
25 
Jz 
float 
(Msun/h)* (Mpc/h)* km/s 
halo angular momentum (physical 
26 
Spin 
float 
halo spin parameter 

27 
Breadth_first_ID 
int64 
ID for breadthfirst ordering of halos
within a tree 

28 
Depth_first_ID 
int64 
ID for depthfirst ordering of halos
within a tree 

29 
Tree_root_ID 
int64 
ID of the halo at the last timestep in
the tree 

30 
Orig_halo_ID 
int64 
original halo ID from halo finder 

31 
Snap_idx 
int64 
Index of snapshot (in the original
snapshot list) from which halo originated 

32 
Next_coprogenitor_ depthfirst_ID 
int64 
depthfirst
ID of next coprogenitor 

33 
Last_progenitor_ depthfirst_ID 
int64 
depthfirst
ID of last progenitor 

34 
Last_mainleaf_ depthfirst_ID 
int64 
depthfirst
ID of last progenitor on main progenitor branch 

35 
Tidal_Force 
float 

Strongest tidal force from any nearby
halo, in dimensionless units (Rhalo / Rhill) 
36 
Tidal_ID 
int64 

ID of halo exerting strongest tidal force 
37 
Rs_Klypin 
float 
scale radius determined using Vmax
and Mvir (see Rockstar
paper) 

38 
Mvir_all 
float 
Msun/h 
Mass enclosed within the specified overdensity, including unbound particles 
39 
M200b 
float 
Msun/h 
Mass enclosed within overdensity
200*rho_b 
40 
M200c 
float 
Msun/h 
Mass enclosed within overdensity
200*rho_crit 
41 
M500c 
float 
Msun/h 
Mass enclosed within overdensity
500*rho_crit 
42 
M2500c 
float 
Msun/h 
Mass enclosed within overdensity
2500*rho_crit 
43 
Xoff 
float 
Kpc/h 
Offset of density peak from average
particle position (comoving) 
44 
Voff 
float 
km/s 
Offset of density peak from average
particle velocity (physical) 
45 
Spin_Bullock 
float 
Bullock spin parameter (J/(sqrt(2)*GMVR)) 

46 
b_to_a 
float 
ratio of second largest shape ellipsoid axes to largest
shape ellipsoid axis (dimensionless); shapes determined by method in Allgood et al. (2006) 

47 
c_to_a 
float 
ratio of smallest shape ellipsoid axes to largest shape
ellipsoid axis (dimensionless) ); shapes determined by method in Allgood et al. (2006) 

48 
A[x] 
float 
Kpc/h 
largest shape ellipsoid axis (comoving) 
49 
A[y] 
float 
Kpc/h 
largest shape ellipsoid axis (comoving) 
50 
A[z] 
float 
Kpc/h 
largest shape ellipsoid axis (comoving) 
51 
b_to_a(500c) 
float 
as above but only for particles within overdensity 500*rho_crit
(dimensionless) 

52 
c_to_a(500c) 
float 
as above but only for particles within overdensity 500*rho_crit
(dimensionless) 

53 
A[x](500c) 
float 
Kpc/h 
as above but only for particles within overdensity 500*rho_crit (comoving) 
54 
A[y](500c) 
float 
Kpc/h 
as above but only for particles within overdensity 500*rho_crit (comoving) 
55 
A[z](500c) 
float 
Kpc/h 
as above but only for particles within overdensity 500*rho_crit (comoving) 
56 
T/U 
float 
ratio of kinetic to potential energies 

57 
M_pe_Behroozi

float 
Msun/h 
Pseudoevolution corrected masses (very
experimental) 
58 
M_pe_Diemer 
float 
Msun/h 
Pseudoevolution corrected masses (very
experimental) 
59 
Halfmass_Radius 
float 
Kpc/h 
Radius within which 1/2 of Mvir is enclosed 
60 
rvmax 
float 
Kpc/h 
Radius at Vmax 
61 
Macc 
float 
Msun/h 
halo mass at accretion 
62 
Mpeak 
float 
Msun/h 
peak mass over accretion history 
63 
Vacc 
float 
Vmax at accretion 

64 
Vpeak 
float 
peak Vmax over accretion history 

65 
Halfmass_Scale 
float 
scale factor at which the most massive progenitor (mmp) reaches 0.5*Mpeak 

66 
Acc_Rate_Inst 
float 
Msun/h/yr 
instantaneous halo mass accretion rate 
67 
Acc_Rate_100Myr 
float 
Msun/h/yr 
halo mass accretion rate averaged over past 100 Myr 
68 
Acc_Rate_1*Tdyn 
float 
Msun/h/yr 
halo mass accretion rate averaged over past 1*virial dynamical time 
69 
Acc_Rate_2*Tdyn 
float 
Msun/h/yr 
halo mass accretion rate averaged over past 2*virial dynamical time 
70 
Acc_Rate_Mpeak 
float 
Msun/h/yr 
growth rate of Mpeak, averaged from
current z to z+0.5 
71 
Acc_Log_Vmax _Inst 
float 
Msun/h/yr 
Instantaneous growth rate of Log10(Vmax) 
72 
Acc_Log_Vmax _1*Tdyn 
float 
Msun/h/yr 
growth rate of Log10(Vmax),
averaged over past 1*virial dynamical time 
73 
Mpeak_Scale 
float 
scale factor at which Mpeak was
reached 

74 
Acc_Scale 
float 
scale factor at which satellites were (last) accreted 

75 
First_Acc_Scale 
float 
scale factor at which current and former satellites first
passed through a larger halo 

76 
First_Acc_Mvir 
float 
Msun/h 
Mvir at First_Acc_scale 
77 
First_Acc_Vmax 
float 
km/s 
Vmax at First_Acc_scale 
78 
Vmax@Mpeak 
float 
km/s 
halo Vmax at the scale at which Mpeak was reached 
79 
Tidal_Force_Tdyn 
float 
Dimensionless tidal force averaged over
past dynamical time 

80 
Log_(Vmax/Vmax _max(Tdyn;Tmpeak)) 
float 
Log10 of Vmax_now
over Vmax@(Tdyn ago) OR Vmax@Mpeak (if and only if Mpeak
happened > 1Tdyn ago) 

81 
Time_to_future _merger 
float 
Gyr 
Time (in Gyr)
until the given halo merges into a larger halo. (1 if no future merger happens) 
82 
Future_merger_ MMP_ID 
int64 
mostmassive progenitor of the halo into which the given
halo merges. (1 if the main progenitor of the future merger halo does not
exist at the given scale factor.) 