TY - JOUR

T1 - The VLA-COSMOS 3 GHz Large Project

T2 - Evolution of Specific Star Formation Rates out to z ∼ 5

AU - Leslie, Sarah K.

AU - Schinnerer, Eva

AU - Liu, Daizhong

AU - Magnelli, Benjamin

AU - Algera, Hiddo

AU - Karim, Alexander

AU - Davidzon, Iary

AU - Gozaliasl, Ghassem

AU - Jiménez-Andrade, Eric F.

AU - Lang, Philipp

AU - Sargent, Mark T.

AU - Novak, Mladen

AU - Groves, Brent

AU - Smolčić, Vernesa

AU - Zamorani, Giovanni

AU - Vaccari, Mattia

AU - Battisti, Andrew

AU - Vardoulaki, Eleni

AU - Peng, Yingjie

AU - Kartaltepe, Jeyhan

PY - 2020/8/1

Y1 - 2020/8/1

N2 - We provide a coherent, uniform measurement of the evolution of the logarithmic star formation rate (SFR)-stellar mass (M*) relation, called the main sequence (MS) of star-forming galaxies , for star-forming and all galaxies out to $z\sim 5$ . We measure the MS using mean stacks of 3 GHz radio-continuum images to derive average SFRs for ∼ 200,000 mass-selected galaxies at z > 0.3 in the COSMOS field. We describe the MS relation by adopting a new model that incorporates a linear relation at low stellar mass (log(M*/M⊙) <10) and a flattening at high stellar mass that becomes more prominent at low redshift (z <1.5). We find that the SFR density peaks at 1.5 <z <2, and at each epoch there is a characteristic stellar mass (M* = 1-4 × 1010M⊙) that contributes the most to the overall SFR density. This characteristic mass increases with redshift, at least to z ∼ 2.5. We find no significant evidence for variations in the MS relation for galaxies in different environments traced by the galaxy number density at 0.3 <z <3, nor for galaxies in X-ray groups at z ∼ 0.75. We confirm that massive bulge-dominated galaxies have lower SFRs than disk-dominated galaxies at a fixed stellar mass at z <1.2. As a consequence, the increase in bulge-dominated galaxies in the local star-forming population leads to a flattening of the MS at high stellar masses. This indicates that "mass quenching" is linked with changes in the morphological composition of galaxies at a fixed stellar mass.

AB - We provide a coherent, uniform measurement of the evolution of the logarithmic star formation rate (SFR)-stellar mass (M*) relation, called the main sequence (MS) of star-forming galaxies , for star-forming and all galaxies out to $z\sim 5$ . We measure the MS using mean stacks of 3 GHz radio-continuum images to derive average SFRs for ∼ 200,000 mass-selected galaxies at z > 0.3 in the COSMOS field. We describe the MS relation by adopting a new model that incorporates a linear relation at low stellar mass (log(M*/M⊙) <10) and a flattening at high stellar mass that becomes more prominent at low redshift (z <1.5). We find that the SFR density peaks at 1.5 <z <2, and at each epoch there is a characteristic stellar mass (M* = 1-4 × 1010M⊙) that contributes the most to the overall SFR density. This characteristic mass increases with redshift, at least to z ∼ 2.5. We find no significant evidence for variations in the MS relation for galaxies in different environments traced by the galaxy number density at 0.3 <z <3, nor for galaxies in X-ray groups at z ∼ 0.75. We confirm that massive bulge-dominated galaxies have lower SFRs than disk-dominated galaxies at a fixed stellar mass at z <1.2. As a consequence, the increase in bulge-dominated galaxies in the local star-forming population leads to a flattening of the MS at high stellar masses. This indicates that "mass quenching" is linked with changes in the morphological composition of galaxies at a fixed stellar mass.

KW - Galaxy evolution

KW - Galaxy quenching

KW - Galaxy bulges

KW - Galaxy environments

KW - Radio continuum emission

KW - Extragalactic radio sources

KW - 594

KW - 2040

KW - 578

KW - 2029

KW - 1340

KW - 508

U2 - 10.3847/1538-4357/aba044

DO - 10.3847/1538-4357/aba044

M3 - Journal article

VL - 899

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1

M1 - 58

ER -