2020/02/29 by Xuejian Shen, Mark Vogelsberger, Dylan Nelson +6 · 1 citation
Physics and Astronomy · #astro-ph.GA #astro-ph.CO
paper · pdf · doi:10.1093/mnras/staa1423
Accepted by MNRAS
arxiv created 2020/05/20 · arxiv updated 2020/05/27
We present predictions for high redshift (z=2-10) galaxy populations based on the IllustrisTNG simulation suite and a full Monte Carlo dust radiative transfer post-processing. Specifically, we discuss the \rm Hα and \rm Hβ + [\rm O III] luminosity functions up to z=8. The predicted \rm Hβ + [\rm O III] luminosity functions are consistent with present observations at z\lesssim 3 with \lesssim 0.1 \rm dex differences in luminosities. However, the predicted \rm Hα luminosity function is ∼ 0.3 \rm dex dimmer than the observed one at z≃ 2. Furthermore, we explore continuum spectral indices, the Balmer break at 4000Å(D4000) and the UV continuum slope β. The median D4000 versus sSFR relation predicted at z=2 is in agreement with the local calibration despite a different distribution pattern of galaxies in this plane. In addition, we reproduce the observed A\rm UV versus β relation and explore its dependence on galaxy stellar mass, providing an explanation for the observed complexity of this relation. We also find a deficiency in heavily attenuated, UV red galaxies in the simulations. Finally, we provide predictions for the dust attenuation curves of galaxies at z=2-6 and investigate their dependence on galaxy colors and stellar masses. The attenuation curves are steeper in galaxies at higher redshifts, with bluer colors, or with lower stellar masses. We attribute these predicted trends to dust geometry. Overall, our results are consistent with present observations of high redshift galaxies. Future JWST observations will further test these predictions.