Herschel-ATLAS: Rapid evolution of dust in galaxies in the last 5 billion years

TL;DR

This study measures how the dust content in galaxies has evolved over the last 5 billion years, revealing significant increases in dust mass and dust-to-stellar mass ratios in massive galaxies at higher redshifts.

Contribution

It provides the first direct, unbiased measurement of galaxy dust mass evolution over 5 billion years using Herschel-ATLAS data, highlighting rapid dust growth in massive galaxies.

Findings

Massive galaxies had five times more dust at z=0.4-0.5.

Dust-to-stellar mass ratio was 3-4 times higher at higher redshift.

Dust content evolution suggests rapid gas consumption and possible changes in star formation fuel.

Abstract

We present the first direct and unbiased measurement of the evolution of the dust mass function of galaxies over the past 5 billion years of cosmic history using data from the Science Demonstration Phase of the Herschel-ATLAS. The sample consists of galaxies selected at 250{\mu}m which have reliable counterparts from SDSS at z < 0.5, and contains 1867 sources. Dust masses are calculated using both a single temperature grey-body model for the spectral energy distribution and also using a model with multiple temperature components. The dust temperature for either model shows no trend with redshift. Splitting the sample into bins of redshift reveals a strong evolution in the dust properties of the most massive galaxies. At z = 0.4 - 0.5, massive galaxies had dust masses about five times larger than in the local Universe. At the same time, the dust-to-stellar mass ratio was about 3-4 times larger, and the optical depth derived from fitting the UV-sub-mm data with an energy balance model was also higher. This increase in the dust content of massive galaxies at high redshift is difficult to explain using standard dust evolution models and requires a rapid gas consumption timescale together with either a more top-heavy IMF, efficient mantle growth, less dust destruction or combinations of all three. This evolution in dust mass is likely to be associated with a change in overall ISM mass, and points to an enhanced supply of fuel for star formation at earlier cosmic epochs.