The dust-to-gas and dust-to-metal ratio in galaxies from z = 0 to 6

Abstract

We present predictions for the evolution of the galaxy dust-to-gas (DGR) and dustto-metal (DTM) ratios from z = 0 → 6, using a model for the production, growth, and destruction of dust grains implemented into the Simba cosmological hydrodynamic galaxy formation simulation. In our model, dust forms in stellar ejecta, grows by the accretion of metals, and is destroyed by thermal sputtering and supernovae. Our simulation reproduces the observed dust mass function at z = 0, but modestly underpredicts the mass function by ∼ ×3 at z ∼ 1 − 2. The z = 0 DGR vs metallicity relationship shows a tight positive correlation for star-forming galaxies, while it is uncorrelated for quenched systems. There is little evolution in the DGR-metallicity relationship between z = 0 − 6. We use machine learning techniques to search for the galaxy physical properties that best correlate with the DGR and DTM. We find that the DGR is primarily correlated with the gas-phase metallicity, though correlations with the depletion timescale, stellar mass and gas fraction are non-negligible. We provide a crude fitting relationship for DGR and DTM vs. the gas-phase metallicity, along with a public code package that estimates the DGR and DTM given a set of galaxy physical properties.

Tracing the evolution of dust-obscured activity using sub-millimetre galaxy populations from STUDIES and AS2UDS

“…We also show the predictions from a semi-analytical model from Popping et al (2017), assuming a fixed time-scale for dust accretion in the ISM of 100 Myr, which we label 'fixed τ ', and another model with no dust accretion. Finally, we plot the predicted dust mass densities from the cosmological hydrodynamic simulation of Li et al (2019) and find that it fits both the low redshift samples and our high redshift observations reasonably well. that the characteristic dust mass of the z ∼ 3.5 sources is higher than that of the z ∼ 1.5 sample, indicating evolution of a factor 8 ± 5 in the characteristic dust mass between z ∼ 1.5 and z ∼ 3.5.…”

“…Combining all these processes to predict the lifetime of dust is, therefore, a complicated task, which several groups have attempted to model. Here, we compare our results to the predicted dust mass densities at different epochs from a semi-analytical model by Popping et al (2017) and hydrodynamical simulation SIMBA by Li et al (2019). These models differ in several features, most notably Popping et al (2017) consider Type Ia SNe to have the same efficiency in dust formation as Type II SNe, while Li et al (2019) do not consider Type Ia SNe to be significant sources of dust production and omit their contribution from their dust formation model.…”

“…We compare our dust mass functions to predictions from a semianalytical model by Popping et al (2017) and hydrodynamical simulations by Li et al (2019), both at z = 2. We see that Popping et al (2017) model underpredicts the observational data at all dust masses, while Li et al (2019) provides a rough match to our observations at z = 1-2. A description of the models and how they compare to observational results is presented in the subsequent section.…”

“…For comparison, we overlay the local (z < 0.1) dust mass function from the GAMA sample of Beeston et al (2018) and z = 2 results from 160-μm survey by Pozzi et al (2020). We also show z = 2 predictions from a semi-analytical model from Popping, Somerville & Galametz (2017) assuming a fixed time-scale for dust accretion in the ISM of 100 Myr, and from the cosmological hydrodynamic simulation SIMBA by Li et al (2019). The difference in the shape of our two dust mass functions indicates that the characteristic dust mass of the high-redshift sources is higher than that of the low-redshift sample.…”

“…In addition, the assumed fixed dust destruction and condensation efficiencies may actually be functions of the local ISM properties. Nevertheless, overall it appears that the assumptions in Li et al (2019), who combine the dust production by AGB stars and Type II SNe, growth by accretion (with a non-constant accretion time-scale) and destruction by thermal sputtering and SNe, may currently provide the best match to observations.…”