TY - JOUR
T1 - A new census of the 0.2 < z < 3.0 universe. i.The stellar mass function
AU - Leja, Joel
AU - Speagle, Joshua S.
AU - Johnson, Benjamin D.
AU - Conroy, Charlie
AU - Van Dokkum, Pieter
AU - Franx, Marijn
N1 - Funding Information:
J.L. is supported by an NSF Astronomy and Astrophysics Postdoctoral Fellowship under award AST-1701487
PY - 2020/4/20
Y1 - 2020/4/20
N2 - There has been a long-standing factor-of-Two tension between the observed star formation rate density and the observed stellar mass buildup after z ∼ 2. Recently, we have proposed that sophisticated panchromatic SED models can resolve this tension, as these methods infer systematically higher masses and lower star formation rates than standard approaches. In a series of papers, we now extend this analysis and present a complete, self-consistent census of galaxy formation over 0.2 < z < 3 inferred with the Prospector galaxy SED-fitting code. In this work, Paper I, we present the evolution of the galaxy stellar mass function using new mass measurements of ∼105 galaxies in the 3D-HST and COSMOS-2015 surveys. We employ a new methodology to infer the mass function from the observed stellar masses: instead of fitting independent mass functions in a series of fixed redshift intervals, we construct a continuity model that directly fits for the redshift evolution of the mass function. This approach ensures a smooth picture of galaxy assembly and makes use of the full, non-Gaussian uncertainty contours in our stellar mass inferences. The resulting mass function has higher number densities at a fixed stellar mass than almost any other measurement in the literature, largely owing to the older stellar ages inferred by Prospector. The stellar mass density is ∼50% higher than previous measurements, with the offset peaking at z ∼ 1. The next two papers in this series will present the new measurements of the star-forming main sequence and the cosmic star formation rate density, respectively.
AB - There has been a long-standing factor-of-Two tension between the observed star formation rate density and the observed stellar mass buildup after z ∼ 2. Recently, we have proposed that sophisticated panchromatic SED models can resolve this tension, as these methods infer systematically higher masses and lower star formation rates than standard approaches. In a series of papers, we now extend this analysis and present a complete, self-consistent census of galaxy formation over 0.2 < z < 3 inferred with the Prospector galaxy SED-fitting code. In this work, Paper I, we present the evolution of the galaxy stellar mass function using new mass measurements of ∼105 galaxies in the 3D-HST and COSMOS-2015 surveys. We employ a new methodology to infer the mass function from the observed stellar masses: instead of fitting independent mass functions in a series of fixed redshift intervals, we construct a continuity model that directly fits for the redshift evolution of the mass function. This approach ensures a smooth picture of galaxy assembly and makes use of the full, non-Gaussian uncertainty contours in our stellar mass inferences. The resulting mass function has higher number densities at a fixed stellar mass than almost any other measurement in the literature, largely owing to the older stellar ages inferred by Prospector. The stellar mass density is ∼50% higher than previous measurements, with the offset peaking at z ∼ 1. The next two papers in this series will present the new measurements of the star-forming main sequence and the cosmic star formation rate density, respectively.
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U2 - 10.3847/1538-4357/ab7e27
DO - 10.3847/1538-4357/ab7e27
M3 - Article
AN - SCOPUS:85085092057
VL - 893
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 2
M1 - 111
ER -