Evolution of Star Formation in the UKIDSS Ultra Deep Survey Field - II. Star Formation as a Function of Stellar Mass Between z=1.46 and z=0.63

TL;DR

This study investigates how the cosmic star formation rate varies with stellar mass from redshift 1.46 to 0.63, revealing a flat distribution with a shifting peak and the importance of dust and metallicity corrections.

Contribution

It provides new insights into the evolution of the star formation rate as a function of stellar mass, emphasizing the significance of dust and metallicity corrections in such analyses.

Findings

The corrected rhoSFR(M) distribution is relatively flat across masses.

The peak of star formation shifts to higher masses at higher redshifts.

Low mass galaxies significantly contribute to star formation at z ~ 1.2.

Abstract

We present new results on the evolution of the cosmic star formation rate as a function of stellar mass in the SXDS-UDS field. We make use of narrow-band selected emission line galaxies in four redshift slices between z = 1.46 and z = 0.63, and compute stellar masses by fitting a series of templates to recreate each galaxy's star formation history. We determine mass-binned luminosity functions in each redshift slice, and derive the star formation rate density (rhoSFR) as a function of mass using the [OIII] or [OII] emission lines. We calculate dust extinction and metallicity as a function of stellar mass, and investigate the effect of these corrections on the shape of the overall rhoSFR(M). We find that both these corrections are crucial for determining the shape of the rhoSFR(M), and its evolution with redshift. The fully corrected rhoSFR(M) is a relatively flat distribution, with the normalisation moving towards lower values of rhoSFR with increasing cosmic time/decreasing redshift, and requiring star formation to be truncated across all masses studied here. The peak of rhoSFR(M) is found in the 10^10.5<Msun<10^11.0 mass bin at z = 1.46. In the lower redshift slices the location of the peak is less certain, however low mass galaxies in the range 10^7.0<Msun<10^8.0 play an important part in the overall rhoSFR(M) out to at least z ~ 1.2.