Morphology & Environment's Role on the Star Formation Rate -- Stellar Mass Relation in COSMOS from 0 < z < 3.5

TL;DR

This study analyzes how environment and morphology influence the star formation rate--stellar mass relation across cosmic time, finding that the high-mass turnover is driven by disk evolution rather than bulge growth.

Contribution

It provides a comprehensive analysis of the star formation main sequence in COSMOS from z=0 to 3.5, showing environmental independence and linking the high-mass turnover to disk properties.

Findings

No environmental dependence on the main sequence shape from z=0 to 3.5.

High-mass turnover is independent of bulge-to-total ratio.

Disk component's specific star formation rate drives the high-mass turnover.

Abstract

We investigate the relationship between environment, morphology, and the star formation rate -- stellar mass relation derived from a sample of star-forming galaxies (commonly referred to as the `star formation main sequence') in the COSMOS field from 0 < z < 3.5. We constructed and fit the FUV--FIR SEDs of our stellar mass-selected sample of 111,537 galaxies with stellar and dust emission models using the public packages MAGPHYS and SED3FIT. From the best fit parameter estimates, we construct the star formation rate -- stellar mass relation as a function of redshift, local environment, NUVrJ color diagnostics, and morphology. We find that the shape of the main sequence derived from our color-color and sSFR-selected star forming galaxy population, including the turnover at high stellar mass, does not exhibit an environmental dependence at any redshift from 0 < z < 3.5. We investigate the role of morphology in the high mass end of the SFMS to determine whether bulge growth is driving the high mass turnover. We find that star-forming galaxies experience this turnover independent of bulge-to-total ratio, strengthening the case that the turnover is due to the disk component's specific star formation rate evolving with stellar mass rather than bulge growth.