The assembly of dusty galaxies at $z geq 4$: statistical properties. (arXiv:1909.07388v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Graziani_L/0/1/0/all/0/1">L. Graziani</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schneider_R/0/1/0/all/0/1">R. Schneider</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ginolfi_M/0/1/0/all/0/1">M. Ginolfi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hunt_L/0/1/0/all/0/1">L.K. Hunt</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Maio_U/0/1/0/all/0/1">U. Maio</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Glatzle_M/0/1/0/all/0/1">M. Glatzle</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ciardi_B/0/1/0/all/0/1">B. Ciardi</a>
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$h^{-1}$ cMpc/size volume down to $z
approx 4$. 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 ($Omega_{rm d}$) is mainly driven by
stellar dust at $z gtrsim 10$, so that mass- and metallicity-dependent yields
are required to assess the dust content in the first galaxies. At $z lesssim
9$ the growth of grains in the ISM of evolved systems
(Log$(M_{star}/M_{odot})>8.5$) significantly increases their dust mass, in
agreement with observations in the redshift range $4 lesssim z < 8$. Our
simulation shows that the variety of high redshift galaxies observed with ALMA
can naturally be accounted for by modeling the grain-growth timescale as a
function of the physical conditions in the gas cold phase. In addition, the
trends of dust-to-metal (DTM) and dust-to-gas (${cal D}$) ratios are
compatible with the available data. A qualitative investigation of the
inhomogeneous dust distribution in a representative massive halo at $z approx
4$ shows that dust is found from the central galaxy up to the closest
satellites along polluted filaments with $rm Log({cal D}) leq -2.4$, but
sharply declines at distances $d gtrsim 30$ kpc along many lines of sight,
where $rm Log({cal D}) lesssim -4.0$.
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$h^{-1}$ cMpc/size volume down to $z
approx 4$. 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 ($Omega_{rm d}$) is mainly driven by
stellar dust at $z gtrsim 10$, so that mass- and metallicity-dependent yields
are required to assess the dust content in the first galaxies. At $z lesssim
9$ the growth of grains in the ISM of evolved systems
(Log$(M_{star}/M_{odot})>8.5$) significantly increases their dust mass, in
agreement with observations in the redshift range $4 lesssim z < 8$. Our
simulation shows that the variety of high redshift galaxies observed with ALMA
can naturally be accounted for by modeling the grain-growth timescale as a
function of the physical conditions in the gas cold phase. In addition, the
trends of dust-to-metal (DTM) and dust-to-gas (${cal D}$) ratios are
compatible with the available data. A qualitative investigation of the
inhomogeneous dust distribution in a representative massive halo at $z approx
4$ shows that dust is found from the central galaxy up to the closest
satellites along polluted filaments with $rm Log({cal D}) leq -2.4$, but
sharply declines at distances $d gtrsim 30$ kpc along many lines of sight,
where $rm Log({cal D}) lesssim -4.0$.
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