# Adam Stevens, 2018 # Functions for reading SAGE data in the format for MultiDark and UNITSIM import numpy as np #from pylab import * import os """ These are the properties (and their units) stored inside the file: SnapNum int32 Snapshot number Type int32 Galaxy type (0=central, 1=satellite) GalaxyIndex int64 Unique galaxy identifier for SAGE. Tracks most massive progenitor CentralGalaxyIndex int64 ID for the central galaxy of the same halo CtreesHaloID int64 Subhalo index from consistent-trees output. Note that we have also encoded whether the galaxy is a 'flyby' by setting this ID to be negative if it is a flyby. The proper consistent-trees output is hence abs(CtreesHaloID). TreeIndex int32 Which (tree)file the galaxy/(sub)halo is stored in CtreesCentralID int64 Central halo index from consistent-trees output mergeType int32 0=none; 1=minor merger; 2=major merger; 3=not used; 4=disrupt to intracluster stars mergeIntoID int32 Position in output of galaxy this one merges into (=-1 if not merging) mergeIntoSnapNum int32 Snapshot number where the merger occurs dT float32 Time interval of last snapshot [Myr/h] Pos 3xfloat32 (x,y,z) coordinates of galaxy [cMpc/h] Vel 3xfloat32 (vx,vy,vz) velocity of galaxy [km/s] Spin 3xfloat32 Specific angular momentum vector of the (sub)halo [pMpc/h km/s] Len int32 Number of particles in the (sub)halo Mvir float32 M200c for centrals (main haloes) or total mass for subhaloes [10^10 Msun / h] CentralMvir float32 M200c of this galaxy's central halo [10^10 Msun / h] Rvir float32 R200c of the (sub)halo [pMpc/h] Vvir float32 `Virial velocity' of the (sub)halo, i.e. orbital velocity at Rvir [km/s] Vmax float32 Maximum rotation velocity of the (sub)halo [km/s] VelDisp float32 Velocity dispersion of the (sub)halo [km/s] ColdGas float32 Cold (disc) gas mass of the galaxy [10^10 Msun / h] StellarMass float32 Total stellar mass of the galaxy [10^10 Msun / h] BulgeMass float32 Stellar mass of the bulge [10^10 Msun / h] HotGas float32 Hot gas in the (sub)halo [10^10 Msun / h] EjectedMass float32 Ejected hot gas associated with the halo [10^10 Msun / h] BlackHoleMass float32 Mass of supermassive black hole [10^10 Msun / h] IntraClusterStars float32 Mass of intracluster stars (zero for satellites) [10^10 Msun / h] MetalsColdGas float32 Mass of metals in the cold gas [10^10 Msun / h] MetalsStellarMass float32 Mass of metals in stars in the galaxy [10^10 Msun / h] MetalsBulgeMass float32 Mass of metals in the bulge stars [10^10 Msun / h] MetalsHotGas float32 Mass of metals in the hot gas [10^10 Msun / h] MetalsEjectedMass float32 Mass of metals in the ejected gas [10^10 Msun / h] MetalsIntraClusterStars float32 Mass of metals in the intracluster stars [10^10 Msun / h] SfrDisk float32 Star formation rate of the disk (averaged over the last time-step) [Msun/yr] SfrBulge float32 Star formation rate of the bulge (averaged over the last time-step) [Msun/yr] SfrDiskZ float32 Average metal abundance (ratio of mass in metals to total mass) of gas that formed stars in the disk over the last time-step SfrBulgeZ float32 Average metal abundance (ratio of mass in metals to total mass) of gas that formed stars in the bulge over the last time-step DiskRadius float32 Exponential disk scale radius [pMpc/h] Cooling float32 log10( Net cooling rate [i.e. heating is already subtracted] of hot gas [erg/s] ) Heating float32 log10( Heating rate from radio mode AGN that suppresses cooling [erg/s] ) QuasarModeBHaccretionMass float32 Mass of the black hole the was obtained from quasar mode accretion [10^10 Msun / h] (the remaining mass of the BH comes from radio mode accretion) TimeOfLastMajorMerger float32 Look-back time of the last major merger [Myr/h] TimeOfLastMinorMerger float32 Look-back time of the last minor merger [Myr/h] OutflowRate float32 Heating rate of cold gas from supernova feedback [Msun / yr] MeanStarAge float32 Mean age (look-back time from z=0) of stars in the galaxy [Myr/h] infallMvir float32 Virial mass of the main halo at the snapshot before this system became a subhalo (only relevant for satellites) [10^10 Msun / h] infallVvir float32 Virial velocity of the main halo at the snapshot before this system became a subhalo [km/s] infallVmax float32 Peak velocity of rotation curve of the main halo at the snapshot before this system became a subhalo [km/s] """ def galdtype_multidark(): Galdesc_full = [ ('SnapNum' , np.int32), ('Type' , np.int32), ('GalaxyIndex' , np.int64), ('CentralGalaxyIndex' , np.int64), ('CtreesHaloID' , np.int64), ('TreeIndex' , np.int32), ('CtreesCentralID' , np.int64), ('mergeType' , np.int32), ('mergeIntoID' , np.int32), ('mergeIntoSnapNum' , np.int32), ('dT' , np.float32), ('Pos' , (np.float32, 3)), ('Vel' , (np.float32, 3)), ('Spin' , (np.float32, 3)), ('Len' , np.int32), ('Mvir' , np.float32), ('CentralMvir' , np.float32), ('Rvir' , np.float32), ('Vvir' , np.float32), ('Vmax' , np.float32), ('VelDisp' , np.float32), ('ColdGas' , np.float32), ('StellarMass' , np.float32), ('BulgeMass' , np.float32), ('HotGas' , np.float32), ('EjectedMass' , np.float32), ('BlackHoleMass' , np.float32), ('IntraClusterStars' , np.float32), ('MetalsColdGas' , np.float32), ('MetalsStellarMass' , np.float32), ('MetalsBulgeMass' , np.float32), ('MetalsHotGas' , np.float32), ('MetalsEjectedMass' , np.float32), ('MetalsIntraClusterStars' , np.float32), ('SfrDisk' , np.float32), ('SfrBulge' , np.float32), ('SfrDiskZ' , np.float32), ('SfrBulgeZ' , np.float32), ('DiskRadius' , np.float32), ('Cooling' , np.float32), ('Heating' , np.float32), ('QuasarModeBHaccretionMass' , np.float32), ('TimeOfLastMajorMerger' , np.float32), ('TimeOfLastMinorMerger' , np.float32), ('OutflowRate' , np.float32), ('MeanStarAge' , np.float32), ('infallMvir' , np.float32), ('infallVvir' , np.float32), ('infallVmax' , np.float32) ] names = [Galdesc_full[i][0] for i in range(len(Galdesc_full))] formats = [Galdesc_full[i][1] for i in range(len(Galdesc_full))] Galdesc = np.dtype({'names':names, 'formats':formats}, align=True) return Galdesc def sageoutsingle(fname, fields=[]): # Read a single SAGE output file, returning all the galaxy data in a record array # fname is the full name for the file to read, including its path # fields is the list of fields you want to read in. If empty, will read all fields. Galdesc = galdtype_multidark() if len(fields)==0: fields=list(Galdesc.names) fin = open(fname, 'rb') # Open the file Ntrees = np.fromfile(fin, np.dtype(np.int32),1) # Read number of trees in file NtotGals = np.fromfile(fin, np.dtype(np.int32),1)[0] # Read number of gals in file. if NtotGals == 0: print('no galaxies in file: ',fname) if (Ntrees != 0): GalsPerTree = np.fromfile(fin, np.dtype((np.int32, Ntrees)),1) # Read the number of gals in each tree G = np.fromfile(fin, Galdesc, NtotGals) # Read all the galaxy data G = G[fields] # Reduce to fields of interest return G def sagesnap(fpre, filelist, fields=[]): # Read full SAGE snapshot, going through each file and compiling into 1 array # fpre is the name of the file up until the _ before the file number # filelist contains all the file numbers you want to read in print(' Loading ',fpre,'_',filelist) Galdesc = galdtype_multidark() if len(fields)==0: fields=list(Galdesc.names) # create empty storage for all galaxy properties (will be removed again at the end) # G = np.empty(1,dtype=Galdesc) # G[:][0] = 0.0 G = np.zeros(1,dtype=Galdesc) # extract fields of interest G = G[fields] # loop over file-extensions given in filelist[] for i in filelist: fname = fpre+'_'+str(i) filesize = os.path.getsize(fname) # capture possibly empty files if filesize > 0: G1 = sageoutsingle(fname, fields) G = np.append(G, G1) # remove the first (empty) field again G = G[:][1:] print(' -> found',len(G[:][:]),' galaxies') return G """ Example code for reading in data, feel free to copy: fields = ['StellarMass', 'CtreesHaloID', 'Type', 'Mvir'] # specify whichever fields you want to read here (refer to the names in the first function). Can leave empty files = range(100) # list of file numbers to read. They don't need to be consecutive. fpre = '/data2/users/astevens/SAGE_output/UNITSIM1/model_z0.000' # where the data are stored, what the common string in the files is before the last underscore G = sagesnap(fpre, files, fields) # Then do, e.g. G['StellarMass'] to get the stellar masses of the galaxies. """