In this catalogue, galaxies are encapsulated in a structure variable in each snapshot. 
Each index of structures corresponds to an individual galaxy.
Each structure variable has the following elements.

ID_HOSTHALO  	 : The ID of the final host halo of a halo merger tree. Thus, it Unique in a whole volume throughout the whole time steps.
ID			 	 : Unique in a tree. Galaxies in other trees can have overlapped ID  
IDX_HOST	 	 : Index number of the central galaxy of this galaxy. Centrals have -1 and galaxies newly formed have -2
IDX_DESCEN	 	 : Index number of the descendant of this galaxy in the next snapshot. -3 for no descendant case (disrupted in dense environments or final snapshot)  
		   	       One can find the descendants of a galaxy by tracking this index in the next snapshot
IDX_MPRG	 	 ; Index number of the main progenitor of this galaxies in the previous snapshot. -3 when there is no progenitor (newly born at this time step).
			       One can find the main progenitors of a galaxy by tracking this index in the previous snapshot
IDX_LPRG	 	 : Index number of the last progenitor of this galaxies in the previous snapshot. idx_mprg=idx_lprg when this galaxy has one progenitor.
		  	       If idx_lprg>idx_mprg, then idx_mprg+1:idx_lprg galaxies merge into this galaxy between the previous and this time step.
N_PRG		 	 : The number of total progenitors of this galaxy. n_prg-1 is the number of galaxies that merge into this galaxies by this time step.
M_HALO		 	 : Halo mass (Msun) If this galaxy is a satellite, then this mass indicate the mass of a subhalo that harbors this galaxy at the central region. 
R_VIR		 	 : Radius of halo
POSITION	 	 : 3 elements array. Position of this galaxy in a volume (Mpc) (Physical scale)
VELOCITY		 : 3 elements array. Velocity of this galaxy in a volume (km/s)
M_STAR			 : Stellar mass in this galaxy (Msun)
M_STAR_BULGE	 : Stellar mass of bulge (Msun)
M_INSITU		 : Stellar mass of in situ components (Msun)
M_STAR_ACCRETED	 : Stellar mass accreted via mergers between the previous and this time step (Msun) 
M_BURST		 	 : Stellar mass formed in merger induced starbursts (Msun)
M_DSC			 : Diffuse stellar component mass in the halo of this galaxy (Msun)
M_HOT		 	 : Hot gas mass in the halo of this galaxy (Msun)
M_COLD		 	 : Cold gas mass in disks (Msun)
M_BH		 	 : Supermassive blackhole mass (Msun)
M_BH_QSO		 : The mass of SMBHs formed in QSO mode (Msun)
SF				 : The amount of stellar mass formed between a time step and the previous step (Msun)
SF_BULGE	 	 : The amount of bulge stellar mass formed between a time step and the previous step (Msun) 
			       In our model, this components are the same to those formed in merger induced star bursts 
SF_CUMULATIVE 	 : Total sum of SF variable in all progenitors. Stellar mass loss is not computed in this value (Msun)
METAL_STAR		 : 4 elements array. Mass of metal[0], He[1], O[2], and Fe[3] in stellar components (Msun)
METAL_STAR_BULGE : 4 elements array. Mass of metal[0], He[1], O[2], and Fe[3] in bulge stellar components (Msun)
METAL_HOT	 	 : 4 elements array. Mass of metal[0], He[1], O[2], and Fe[3] in hot gas (Msun)
METAL_COLD	 	 : 4 elements array. Mass of metal[0], He[1], O[2], and Fe[3] in cols gas (Msun)
METAL_SF		 : 4 elements array. Mass of metal[0], He[1], O[2], and Fe[3] in newly formed stars (Msun)
METAL_SF_BULGE   : 4 elements array. Mass of metal[0], He[1], O[2], and Fe[3] in newly formed bulge stars (Msun)
LUM				 : 2 elements array. Luminosity of all stars in B [0] and V[1] bands
LUM_BULGE		 : 2 elements array. Luminosity of bulge stars in B [0] and V[1] bands
AGE_M_STAR		 : Mass weighted age of stellar components (Gyr)
AGE_M_INSITU  	 : Mass weighted age of in situ components (Gyr)
AGE_LUM		 	 : 2 elements array. Luminosity weighted age of stars in B [0] and V[1] bands