Constraints: Baryonic Physics - galacticusorg/galacticus GitHub Wiki

To constrain the baryonic physics of Galacticus we use a variety of observational datasets. This is work in progress, as we gradually add more datasets to the set used to constrain Galacticus.

Currently, the datasets used to constrain the parameters of baryonic physics in Galacticus are:

• the stellar mass-halo mass relation of Leauthaud et al. (2012) (at z=0.22 to 0.48 and z=0.74 to 1.00);
• the scatter in the stellar mass-halo mass relation at fixed halo mass, assumed to be σ_{log M}=0.16 (More et al. 2009; at z=0.22 to 0.48 and z=0.74 to 1.00);
• the z < 0.06 stellar mass function of galaxies from the GAMA survey (Baldry et al. 2012);
• the z = 2.5-3.0 stellar mass function of galaxies from the ULTRAVISTA survey (Muzzin et al. 2013);
• the z ≅ 0.00 HI mass function of galaxies from the ALFALFA survey (Martin et al. 2010);
• the z ≅ 0.00 black hole mass-bulge mass relation (Kormedy & Ho 2013);
• size distributions of early- and late-type SDSS galaxies in diffrent mass ranges (Shen et al. 2003);
• the Hα luminosity functions from HiZELS (Sobral et al. 2013) and GAMA (Gunawardhana et al. (2013));
• the g and r-band luminosity functions of SDSS galaxies (Montero-Dorta & Prada 2009);
• the gas-phase mass-metallicity relation (Blanc et al. 2019);
• the morphological fraction as a function of stellar mass from GAMA (Moffett et al. 2016).
• the luminosity function of Milky Way satellite galaxies;

We allow 50 model parameters (of which 20 which model systematic errors in the observational data, with the remaining 30 describing the baryonic physics of Galacticus) to vary, and optimize their values using a particle swarm optimization (PSO) algorithm.

The resulting best-fit model parameters are given in this file, while the parameter file to perform the PSO can be found here.

Plots of the datasets used to constrain Galacticus, along with the results from the best-fit model are shown below.