Abstract
The dust-to-stellar mass ratio (Mdust/M?) is a crucial yet poorly constrained quantity to understand the complex physical processes involved in the production of dust, metals and stars in galaxy evolution. In this work we explore trends of Mdust/M? with dierent physical parameters using observations of 300 massive, dusty star-forming galaxies detected with ALMA up to z 5. Additionally, we interpret our findings with dierent models of dusty galaxy formation. We find that Mdust/M? evolves with redshift, stellar mass,
specific star formation rate and integrated dust size, dierently for main sequence and starburst galaxies. In both galaxy populations Mdust/M? increases until z 2 followed by a roughly flat trend towards higher redshifts, suggesting ecient dust growth in the distant universe. We confirm that the inverse relation between Mdust/M? and M? holds up to z 5 and can be interpreted as an evolutionary
transition from early to late starburst phases.We demonstrate that Mdust/M? in starbursts reflects the increase in molecular gas fraction
with redshift, and attains the highest values for sources with the most compact dusty star-formation. The state-of-the-art cosmological simulations that include self-consistent dust growth, broadly reproduce the evolution of Mdust/M? in main sequence galaxies, but underestimate it in starbursts. The latter is found to be linked to lower gas-phase metallicities and
longer dust growth timescales relative to observations. Phenomenological models based on the main-sequence/starburst dichotomy and analytical models that include recipes for rapid metal enrichment are consistent with our observations. Therefore, our results strongly suggest that high Mdust/M? is due to rapid dust grain growth in metal enriched interstellar medium. This work highlights multifold benefits of using Mdust/M? as a diagnostic tool for: (1) disentangling main sequence and starburst galaxies up to z 5; (2)
probing the evolutionary phase of massive objects; and (3) refining the treatment of the dust life cycle in simulations.
specific star formation rate and integrated dust size, dierently for main sequence and starburst galaxies. In both galaxy populations Mdust/M? increases until z 2 followed by a roughly flat trend towards higher redshifts, suggesting ecient dust growth in the distant universe. We confirm that the inverse relation between Mdust/M? and M? holds up to z 5 and can be interpreted as an evolutionary
transition from early to late starburst phases.We demonstrate that Mdust/M? in starbursts reflects the increase in molecular gas fraction
with redshift, and attains the highest values for sources with the most compact dusty star-formation. The state-of-the-art cosmological simulations that include self-consistent dust growth, broadly reproduce the evolution of Mdust/M? in main sequence galaxies, but underestimate it in starbursts. The latter is found to be linked to lower gas-phase metallicities and
longer dust growth timescales relative to observations. Phenomenological models based on the main-sequence/starburst dichotomy and analytical models that include recipes for rapid metal enrichment are consistent with our observations. Therefore, our results strongly suggest that high Mdust/M? is due to rapid dust grain growth in metal enriched interstellar medium. This work highlights multifold benefits of using Mdust/M? as a diagnostic tool for: (1) disentangling main sequence and starburst galaxies up to z 5; (2)
probing the evolutionary phase of massive objects; and (3) refining the treatment of the dust life cycle in simulations.
| Original language | English |
|---|---|
| Number of pages | 17 |
| Journal | Astronomy and Astrophysics |
| Publication status | Accepted/In press - 17 Aug 2020 |
Keywords
- astro-ph.GA