• Glatzle, M.
• Ciardi, B.
• Schneider, R.
• Hunt, L. K.
• Ginolfi, Michele
• Graziani, L.
• Maio, U.

Abstract

The recent discovery of high-redshift dusty galaxies implies a rapid dust enrichment of their interstellar medium (ISM). To interpret these observations, we run a cosmological simulation in a 30 h<SUP>-1</SUP> cMpc/size volume down to z ≍ 4. We use the hydrodynamical code dustygadget, which accounts for the production of dust by stellar populations and its evolution in the ISM. We find that the cosmic dust density parameter (Ω<SUB>d</SUB>) is mainly driven by stellar dust at z ≳ 10, so that mass- and metallicity-dependent yields are required to assess the dust content in the first galaxies. At z ≲ 9, the growth of grains in the ISM of evolved systems [log(M<SUB>⋆</SUB>/M<SUB>☉</SUB>) &gt; 8.5] significantly increases their dust mass, in agreement with observations in the redshift range 4 ≲ z &lt; 8. Our simulation shows that the variety of high-redshift galaxies observed with the Atacama Large Millimeter Array can naturally be accounted for by modelling the grain growth time-scale as a function of the physical conditions in the gas cold phase. In addition, the trends of dust-to-metal and dust-to-gas (D) ratios are compatible with the available data. A qualitative investigation of the inhomogeneous dust distribution in a representative massive halo at z ≍ 4 shows that dust is found from the central galaxy up to the closest satellites along polluted filaments with log(D) ≤ -2.4, but sharply declines at distances d ≳ 30 kpc along many lines of sight, where log(D) ≲ -4.0....

Topics

• density
• impedance spectroscopy
• grain
• phase
• simulation
• grain growth