http://arxiv.org/abs/2008.06514
We use a statistical approach to study the evolution of the star-forming galaxy (SFG) main sequence (MS) and the fraction of dust-obscured star formation up to $z\sim4$. We use the following observables: the far-ultraviolet, FUV, and the infrared, IR, luminosity functions, LFs, and the galaxy stellar mass function (GSMF) of SFGs. Our derived total (FUV+IR) star formation rates, SFR, reproduce the evolution of the MS as compared to a set of independent observational inferences. At any redshift, we find that the specific SFR$-M_{\ast}$ relation for MS SFGs approaches to a power law at the high-mass end. At lower masses it bends and eventually the slope sign changes from negative to positive at very low masses. At $z\sim0$, this change of sign is at $M_{\ast}\sim5\times10^{8} M_{\odot}$ close to dust-obscured star formation regime, $M_{\ast}\sim6\times10^{8}M_{\odot}$. The slope sign change is related to the knee of the FUV LF. We predict that the assembly time of nearby dwarf galaxies is $\sim10$ Gyrs consistent with their oldest observed stellar populations. Our derived dust-obscured fractions agree with previous determinations at $0\leq z\leq2.5$. The dust-obscured fraction depends strongly on mass with almost no dependence with redshift above $z\sim1.2$. At $z\lesssim0.75$ high-mass galaxies become more “transparent” compared to their high redshift counterparts. On the opposite, low- and intermediate-mass galaxies have become more obscured by dust. Using the joint evolution of the GSMF and the FUV and IR LFs is a promising empirical approach to study the stellar mass growth and dust formation/destruction mechanisms, and ultimately to constrain galaxy formation models.
A. Rodriguez-Puebla, V. Avila-Reese, M. Cano-Diaz, et. al.
Tue, 18 Aug 20
-994/70
Comments: Submitted to ApJ, 18 pages, 11 figures. Comments are welcome
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