Column#
Name
Type
Unit
Description
scale
float
scale factor, same as in snapshot-redshifts table
1
id
int64
unique ID for the halo
2
desc_scale
float
scale factor of the descendant halo, if applicable
3
desc_id
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 semi-analytic 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 breadth-first ordering of halos within a tree
28
Depth_first_ID
int64
ID for depth-first ordering of halos within a tree
29
Tree_root_ID
int64
ID of the halo at the last time-step 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 field from any nearby halo, in dimensionless units (Rhalo / Rhill). Here "nearby" means within 25 Mpc/h comoving distance. This is applied only for Uchuu. mini- and micro-Uchuu do not have this limitation.
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
Pseudo-evolution corrected masses (very experimental)
58
M_pe_Diemer
float
Msun/h
Pseudo-evolution 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
most-massive 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.)