Galaxy-Halo connection

Galaxy-Halo connection#

The HOD model#

TODO

Explain the HOD model w/ references

Implementation#

The acm.hod module is a wrapper around the AbacusHOD class. It is used to populate galaxies in AbacusSummit Dark Matter catalogs.

It contains several classes, to generate different types of catalogs : BoxHOD to generate cubic boxes, CutskyHOD to generate cutsky catalogs, and LightconeHOD to generate lightcone catalogs.

Note

A different dark matter catalog can be provided to BoxHOD and CutskyHOD, if necessary. The acm.data.paths module provides different Dark matter catalogs. The default catalog used is tailored for LRGs (LRG_Abacus_DM), but a BGS catalog (BGS_Abacus_DM) is also available.

To select a Latin HyperCube (LHC) of HOD parameters, the acm.hod.parameters module provides the HODLatinHypercube class:

from acm.hod.parameters import HODLatinHypercube
from sunbird.inference.priors import Yuan23

ranges = Yuan23().ranges # priors for the HOD parameters

lhc = HODLatinHypercube(ranges)
params = lhc.sample(50_000)  # number of HOD variations

params = lhc.split_by_cosmo(cosmos=[0, 1])
lhc.save_params('./')

TODO

Maybe explain how the cutsky/lightcones are constructed ?

API#

Contents