A survey of high-$z$ galaxies: SERRA simulations

Abstract

We introduce serra, a suite of zoom-in high-resolution (∼ 10 pc) cosmological simulations including non-equilibrium chemistry and on-the-fly radiative transfer. The outputs are post-processed to derive galaxy UV+FIR continuum and emission line properties. Results are compared with available multi-wavelength data to constrain the physical properties (e.g., star formation rates, stellar/gas/dust mass, metallicity) of high-redshift 6 < ∼ z < ∼ 15 galaxies. This flagship paper focuses on the z = 7.7 sub-sample, including 207 galaxies with stellar mass 10 7 M < ∼ M < ∼ 5×10 10 M , and specific star formation ranging from sSFR ∼ 100 Gyr −1 in young, low-mass galaxies to ∼ 10 Gyr −1 for older, massive ones. At this redshift, serra galaxies are typically bursty, i.e. they are located above the Schmidt-Kennicutt relation by a factor κ s = 3.03 +4.9 −1.8 , consistent with recent findings for [O III] and [C II] emitters at high-z. They also show relatively large IRX = L FIR /L UV values as a result of their compact/clumpy morphology effectively blocking the stellar UV luminosity. Note that this conclusion might be affected by insufficient spatial resolution at the molecular cloud level. We confirm that early galaxies lie on the standard [C II]−SFR relation; their observed L [OIII] /L [CII] 1−10 ratios are reproduced without the need of a top-heavy IMF and/or anomalous C/O abundances. [O I] line intensities are similar to local ones, making ALMA high-z detections challenging but feasible (∼ 6 hr for an SFR of 50 M yr −1 ).

The REBELS ALMA Survey: cosmic dust temperature evolution out to z $\sim$ 7

“…We also tested our method on simulations, applying it to the z ∼ 6.7 galaxy Zinnia (a.k.a. serra05:s46:h0643) from the SERRA simulation suite (Pallottini et al 2019, see also Pallottini et al 2022). Also in this case, we recover T d in agreement with single-temperature grey body SED fitting performed at the frequencies corresponding to ALMA bands 6, 7, and 8.…”

“…Finally the lower dust-tometal ratio predicted for early galaxies from simulations at z > ∼ 5 (see e.g. Aoyama et al 2017;Behrens et al 2018;Shen et al 2021;Pallottini et al 2022) could also motivate the presence of hot dust at high-z. In fact, a lower dust content results in warmer dust temperatures for a given L FIR .…”

“…Other works have suggested that the increasing T d (z) trend can be qualitatively ascribed to the growing specific star formation rate at high-z (Magnelli et al 2014;Ma et al 2016Ma et al , 2019Shen et al 2021), together with the lower dust content of early galaxies (see e.g. Aoyama et al 2017;Behrens et al 2018;Shen et al 2021;Pallottini et al 2022). A lower dust content would in fact result in warmer dust temperatures for a given FIR luminosity L FIR .…”

CONCERTO: High-fidelity simulation of millimeter line emissions of galaxies and [CII] intensity mapping

“…As pointed by Ferrara et al (2019), massive high-redshift galaxies correspond much high [CII] surface brightness regime than the initial low-redshift De Looze et al ( 2014) observations and it is almost surprising that this relation remains valid under these physical conditions. While numerical simulations (Arata et al 2020;Pallottini et al 2019Pallottini et al , 2022 predict that the local relation is respected also for M < 10 9 M galaxies, we currently have no strong observational support for this and we cannot guarantee that a [CII]-deficit does not appear at low-mass (M < 10 9.5 M ) or higher redshift (z>6), where the metallicity is expected to be much lower. To test this scenario, we also implemented the Lagache et al (2018, hereafter L18) relation predicted by a semi-analytical model, which produce a lower [CII] luminosity at higher redshifts and lower SFRs:…”

“…Observational studies at low redshift (e.g., De Looze et al 2014;Herrera-Camus et al 2015) and high redshift (e.g., Capak et al 2015;Schaerer et al 2020;Carniani et al 2020) found a non-evolving and nearlylinear empirical correlation between [CII] luminosity and SFR. Both numerical simulations (Vallini et al 2015;Olsen et al 2017;Lupi & Bovino 2020;Pallottini et al 2022) and semianalytical models (Lagache et al 2018;Popping et al 2019) predict a weakly evolving relation with redshift. The [CII] line is thus a suitable tracer of the high-z star formation at large scales.…”