Matching the Evolution of the Stellar Mass Function Using Log-normal Star Formation Histories

Abstract

We show that a model consisting of individual, log-normal star formation histories for a volume-limited sample of $z\approx 0$ galaxies reproduces the evolution of the total and quiescent stellar mass functions at $z\lesssim 2.5$ and stellar masses $M_{\ast }\ge 10^{10}{\mathrm{M}}_{\odot }$. This model has previously been shown to reproduce the star formation rate/stellar mass relation ($\mathrm{SFR}$--$M_{\ast }$) over the same interval, is fully consistent with the observed evolution of the cosmic $\mathrm{SFR}$ density at $z\le 8$, and entails no explicit "quenching" prescription. We interpret these results/features in the context of other models demonstrating a similar ability to reproduce the evolution of (1) the cosmic $\mathrm{SFR}$ density, (2) the total/quiescent stellar mass functions, and (3) the $\mathrm{SFR}$--$M_{\ast }$ relation, proposing that the key difference between modeling approaches is the extent to which they stress/address diversity in the (starforming) galaxy population. Finally, we suggest that observations revealing the timescale associated with dispersion in $\mathrm{SFR}(M_{\ast })$ will help establish which models are the most relevant to galaxy evolution.

5 pages, 2 figures; submitted to ApJ Letters

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• Cosmic Star Formation History
• Mass and environment as drivers of galaxy evolution in SDSS and zCOSMOS and the origin of the Schechter function
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• PRIMUS: Constraints on Star Formation Quenching and Galaxy Merging, and the Evolution of the Stellar Mass Function From z=0-1
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Cited by in corpus (1)

• Demonstrating Diversity in Star Formation Histories with the CSI Survey