Bridging between the Integrated and Resolved Main Sequence of Star Formation
Abstract
The position of galaxies on the stellar mass, star formation rate (SFR) plane with respect to the star-forming main sequence at each redshift is a convenient way to infer where the galaxy is in its evolution compared to the rest of the population. We use Hubble Space Telescope high-resolution images in the GOODS-S field from the the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS) and fit multiwavelength lights in resolution elements of galaxies with stellar population synthesis models. We then construct resolved kpc-scale stellar mass, SFR surface density curves for galaxies at z ∼ 1. Fitting these resolved main sequence curves with Schechter functions, we parameterize and explain the multiwavelength structure of galaxies with three variables: φ*, α, and M*. For quenched galaxies below the main sequence, we find an average high-mass slope (α) of the resolved main sequence curves to be ∼-0.4. The scatter of this slope is higher among the lower mass star-forming galaxies and those above the main sequence compared to quenched galaxies, due to lack of an evolved bulge. Our findings agree well with an inside-out quenching of star formation. We find that the knee of the Schechter fits (M*) for galaxies below the main sequence occurs at lower stellar mass surface densities compared to star-forming galaxies, which hints at how far quenching has proceeded outward.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 2020
- DOI:
- 10.3847/2041-8213/ab7243
- arXiv:
- arXiv:2002.01011
- Bibcode:
- 2020ApJ...896L..17H
- Keywords:
-
- Galaxies;
- Star formation;
- Galaxy quenching;
- Galaxy structure;
- Galaxy bulges;
- Dynamical evolution;
- Astrostatistics;
- Galaxy evolution;
- 573;
- 1569;
- 2040;
- 622;
- 578;
- 421;
- 1882;
- 594;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 5 pages, 3 figures, Accepted for publication by ApJL