HaloCatalogues | Skies & Universes

Uchuu DR1 Halo Catalogues

The halo catalogues are created using the ROCKSTAR halo finder and consisted-trees code (Behroozi et al. 2013a, Behroozi et al. 2013b). See Ishiyama et al. (2020) for details.

We provide halo catalogues for Uchuu, mini-Uchuu, micro-Uchuu and Shin-Uchuu.

For Uchuu the number of files per snapshot (redshift) is 100 with a total size ~1TB (when you find a distinct halo in a file, you can always find its subhalos in the same file). The entire data set is 36TB. In addition, trimmed versions (and thus smaller size) of the Uchuu halo catalogues for halos with Mvir > 1e11 Msun/h (2TB total) and Mvir > 1e12 Msun/h (132GB total) are also provided.

For Shin-Uchuu the number of files per snapshot (redshift) is one. The entire data set is 4.3TB. In addition, trimmed versions (and thus smaller size) of the Shin-Uchuu halo catalogues for halos with Mvir > 1e9 Msun/h (189GB total) are also provided.

How to download and work with the data

The table below provides the description of all 83 columns in the halo catalogues (listed in arbitrary order).

Column#	Name	Type	Unit	Description
0	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.)