Semi-analytic forecasts for JWST - I. UV luminosity functions at z = 4 - 10

TL;DR

This paper provides semi-analytic predictions for high-redshift galaxy UV luminosity functions and number counts for JWST, exploring how different physical models affect observable properties to inform galaxy formation theories.

Contribution

It offers updated, calibrated predictions for UV luminosity functions and galaxy counts at z=4-10, incorporating various physical model variations for JWST observations.

Findings

Predicted UV luminosity functions from z=4 to 10.

Quantified effects of physical model variations on observables.

Provided data tables for JWST galaxy count forecasts.

Abstract

In anticipation of the upcoming deployment of the James Webb Space Telescope (JWST), we present high-redshift predictions by the well-established Santa Cruz semi-analytic model. We update the models by re-calibrating them after adopting cosmological parameters consistent with recent constraints from Planck. We provide predictions for rest-frame UV luminosity functions for galaxy populations over a wide range of $M_\text{UV}$ from $\sim-6$ to $\sim-24$ between $z = 4 - 10$. In addition, we present the corresponding predictions for observed-frame galaxy number counts in different redshift bins in the full set of NIRCam filters. We provide predictions of the quantitative effect on these observables of varying the physical recipes implemented in the models, such as the molecular gas depletion time (star formation efficiency) scalings or the scalings of outflow rates driven by stars and supernovae with galaxy circular velocity. Based on these results, we discuss what may be learned about the physical processes that shape galaxy formation from JWST observations of galaxy number densities at different intrinsic luminosities. All data tables for the results presented in this work are available at https://www.simonsfoundation.org/semi-analytic-forecasts-for-jwst/.