Biasing relation, environmental dependencies and estimation of the growth rate from star forming galaxies

TL;DR

This study investigates the relationship between star formation rate and dark matter, assessing environmental effects on growth rate estimation using mock galaxy catalogs, and finds the method's robustness for upcoming surveys.

Contribution

It demonstrates that the speed-from-light method reliably estimates the growth rate from star forming galaxies without environmental bias across different models.

Findings

The method yields a precision of σ_β < 0.17 at z=1.

Errors in growth rate are comparable to redshift space distortion analyses.

SFR distribution varies with environment, generally skewed higher in denser regions.

Abstract

The connection between galaxy star formation rate (SFR) and dark matter (DM) is of paramount importance for the extraction of cosmological information from next generation spectroscopic surveys that will target emission line star forming galaxies. Using publicly available mock galaxy catalogs obtained from various semi-analytic models (SAMs) we explore the SFR-DM connection in relation to the speed-from-light method (Feix et al. 2016) for inferring the growth rate, $f$, from luminosity/SFR shifts. Emphasis is given to the dependence of the SFR distribution on the environment density on scales of 10s-100s Mpc. We show that the application of the speed-from-light method to an Euclid-like survey is not biased by environmental effects. In all models, the precision on the measured $\beta=f/b$ parameter is $\sigma_\beta < 0.17$ at $z=1$. This translates into errors of $\sigma_f \sim 0.22$ and $\sigma_{(f\sigma_8)}\sim 0.1$, without invoking assumptions on the mass power spectrum. These errors are in the same ballpark as recent analyses of the redshift space distortions in galaxy clustering. In agreement with previous studies, the bias factor, $b$ is roughly a scale-independent, constant function of the SFR for star forming galaxies. Its value at $z=1$ ranges from $1.2$ to $1.5$ depending on the SAM recipe. Although in all SAMs denser environments host galaxies with higher stellar masses, the dependence of the SFR on the environment is more involved. In most models the SFR probability distribution is skewed to larger values in denser regions. One model exhibits an inverted trend where high SFR is suppressed in dense environment.