Cosmic evolution of grain size distribution in galaxies using the $\nu^2$GC semi-analytic model

TL;DR

This paper models the evolution of dust grain size distribution in galaxies over cosmic time using the $ u^2$GC semi-analytic model, reproducing observed relations and predicting extinction curve variations.

Contribution

It introduces a semi-analytical model that predicts dust grain size evolution and extinction properties across cosmic history, aligning with observations and revealing new correlations.

Findings

Model reproduces local dust-to-gas ratio and MW extinction curve.

Grain size distribution evolves from large to small grains with galaxy evolution.

Extinction curves vary from flat to steep depending on galaxy evolution stage.

Abstract

We investigate the cosmological evolution of interstellar dust with a semi-analytical galaxy formation model ($\nu^2$GC), focusing on the evolution of grain size distribution. The model predicts the statistical properties of dust mass and grain size distribution in galaxies across cosmic history. We confirm that the model reproduces the relation between dust-to-gas ratio and metallicity in the local Universe, and that the grain size distributions of the Milky Way (MW)-like sample become similar to the so-called MRN distribution that reproduces the observed MW extinction curve. Our model, however, tends to overpredict the dust mass function at the massive end at redshift $z\lesssim 0.8$ while it reproduces the abundance of dusty galaxies at higher redshifts. We also examine the correlation between grain size distribution and galaxy properties (metallicity, specific star formation rate, gas fraction, and stellar mass), and observe a clear trend of large-grain-dominated, small-grain-dominated, and MRN-like grain size distributions from unevolved to evolved stages. As a consequence, the extinction curve shapes are flat, steep, and intermediate (MW-like) from the unevolved to evolved phases. At a fixed metallicity, the grain size distribution tends to have larger fractions of small grains at lower redshift; accordingly, the extinction curve tends to be steeper at lower redshift. We also predict that supersolar-metallicity objects at high redshift have flat extinction curves with weak 2175 \AA bump strength.