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We report the discovery of Cerberus, an extremely red object detected with the MIRI Deep Imaging Survey (MIDIS) observations in the F1000W filter of the Hubble Ultra Deep Field. The object is detected at $S/N\sim6$, with $\mathrm{F1000W}\sim27$ mag, and undetected in the NIRCam data gathered by the JWST Advanced Deep Extragalactic Survey, JADES, fainter than the 30.0-30.5 mag $5\sigma$ detection limits in individual bands, as well as in the MIDIS F560W ultra-deep data ($\sim$29 mag, $5\sigma$). Analyzing the spectral energy distribution built with low-$S/N$ ($<5$) measurements in individual optical-to-mid-infrared filters and higher $S/N$ ($\gtrsim5$) in stacked NIRCam data, we discuss the possible nature of this red NIRCam-dark source using a battery of codes. We discard the possibility of Cerberus being a Solar System body based on the $<0.016$" proper motion in the 1-year apart JADES and MIDIS observations. A sub-stellar Galactic nature is deemed unlikely, given that the Cerberus' relatively flat NIRCam-to-NIRCam and very red NIRCam-to-MIRI flux ratios are not consistent with any brown dwarf model. The extragalactic nature of Cerberus offers 3 possibilities: (1) A $z\sim0.4$ galaxy with strong emission from polycyclic aromatic hydrocarbons; the very low inferred stellar mass, $\mathrm{M}_\star=10^{5-6}$ M$_\odot$, makes this possibility highly improbable. (2) A dusty galaxy at $z\sim4$ with an inferred stellar mass $\mathrm{M}_\star\sim10^{8}$ M$_\odot$. (3) A galaxy with observational properties similar to those of the reddest little red dots discovered around $z\sim7$, but Cerberus lying at $z\sim15$, with the rest-frame optical dominated by emission from a dusty torus or a dusty starburst., Comment: Accepted for publication in ApJL, results unchanged, manuscript shortened to publish as a letter

We investigate the properties of strong (Hb+[OIII]) emitters before and after the end of the Epoch of Reionization from z=8 to z=5.5. We make use of ultra-deep JWST/NIRCam imaging in the Parallel Field of the MIRI Deep Imaging Survey (MIDIS) in the Hubble eXtreme Deep Field (P2-XDF), in order to select prominent (Hb+[OIII]) emitters (with rest EW_0 > 100 Angstroms) at z=5.5-7, based on their flux density enhancement in the F356W band with respect to the spectral energy distribution continuum. We complement our selection with other (Hb+[OIII]) emitters from the literature at similar and higher (z=7-8) redshifts. We find (non-independent) anti-correlations between EW_0(Hb+[OIII]) and both galaxy stellar mass and age, in agreement with previous studies, and a positive correlation with specific star formation rate (sSFR). On the SFR-M* plane, the (Hb+[OIII]) emitters populate both the star-formation main sequence and the starburst region, which become indistinguishable at low stellar masses (log10(M*) < 7.5). We find tentative evidence for a non-monotonic relation between EW_0(Hb+[OIII]) and SFR, such that both parameters correlate with each other at SFR > 1 Msun/yr, while the correlation flattens out at lower SFRs. This suggests that low metallicities producing high EW_0(Hb+[OIII]) could be important at low SFR values. Interestingly, the properties of the strong emitters and other galaxies (33% and 67% of our z=5.5-7 sample, respectively) are similar, including, in many cases, high sSFR. Therefore, it is crucial to consider both emitters and non-emitters to obtain a complete picture of the cosmic star formation activity around the Epoch of Reionization., Comment: 14 pages, 8 figures. Accepted for publication at the ApJ. Version v3 includes minor update to match journal version

The evolution of the cosmic dust content and the cycle between metals and dust in the interstellar medium (ISM) play a fundamental role in galaxy evolution. The chemical enrichment of the Universe can be traced through the evolution of the dust-to-metals ratio (DTM) and the dust-to-gas ratio (DTG) with metallicity. We use a novel method to determine mass estimates of the DTM, DTG and dust composition based on our previous measurements of the depletion of metals in different environments (the Milky Way, the Magellanic Clouds, and damped Lyman-$\alpha$ absorbers, DLAs, toward quasars and towards gamma-ray bursts, GRBs), which were calculated from the relative abundances of metals in the ISM through absorption-line spectroscopy column densities observed mainly from VLT/UVES and X-shooter, and HST/STIS. We derive the dust extinction from the estimated dust depletion ($A_{V, \rm depl}$) and compare with the $A_{V}$ from extinction. We find that the DTM and DTG ratios increase with metallicity and with the dust tracer [Zn/Fe]. This suggests that grain growth in the ISM is a dominant process of dust production. The increasing trend of the DTM and DTG with metallicity is in good agreement with a dust production and evolution model. Our data suggest that the stellar dust yield is much lower than the metal yield and thus that the overall amount of dust in the warm neutral medium that is produced by stars is much lower. We find that $A_{V,\rm depl}$ is overall lower than $A_{V, \rm ext}$ for the Milky Way and a few Magellanic Clouds lines of sight, a discrepancy that is likely related to the presence of carbonaceous dust. We show that the main elements that contribute to the dust composition are, O, Fe, Si, Mg, C, S, Ni and Al for all the environments. Abundances at low dust regimes suggest the presence of pyroxene and metallic iron in dust., Comment: Accepted for publication in A&A. Abstract abridged

We study the stellar population properties of 182 spectroscopically-confirmed (MUSE/VLT) Lyman-$\alpha$ emitters (LAEs) and 450 photometrically-selected Lyman-Break galaxies (LBGs) at z = 2.8 - 6.7 in the Hubble eXtreme Deep Field (XDF). Leveraging the combined power of HST and JWST NIRCam and MIRI observations, we analyse their rest-frame UV-through-near-IR spectral energy distributions (SEDs) with MIRI playing a crucial role in robustly assessing the LAE's stellar mass and ages. Our LAEs are low-mass objects (log$_{10}$(M$_\star$[M$_\odot$]) ~ 7.5), with little or no dust extinction (E(B - V) ~ 0.1) and a blue UV continuum slope ($\beta$ ~ -2.2). While 75% of our LAEs are young (< 100 Myr), the remaining 25% have significantly older stellar populations (> 100 Myr). These old LAEs are statistically more massive, less extinct and have lower specific star formation rate (sSFR) compared to young LAEs. Besides, they populate the M$_\star$ - SFR plane along the main-sequence (MS) of star-forming galaxies, while young LAEs populate the starburst region. The comparison between the LAEs properties to those of a stellar-mass matched sample of LBGs shows no statistical difference between these objects, except for the LBGs redder UV continuum slope and marginally larger E(B - V) values. Interestingly, 48% of the LBGs have ages < 10 Myr and are classified as starbursts, but lack detectable Ly$\alpha$ emission. This is likely due to HI resonant scattering and/or selective dust extinction. Overall, we find that JWST observations are crucial in determining the properties of LAEs and shedding light on the properties and similarities between LAEs and LBGs., Comment: 22 pages, 15 figures, 5 tables. Accepted for publication in APJ

We present deep James Webb Space Telescope (JWST)/MIRI F560W observations of a flux-limited, ALMA-selected sample of 28 galaxies at z=0.5-3.6 in the Hubble Ultra Deep Field (HUDF). The data from the MIRI Deep Imaging Survey (MIDIS) reveal the stellar structure of the HUDF galaxies at rest-wavelengths of >1 micron for the first time. We revise the stellar mass estimates using new JWST photometry and find good agreement with pre-JWST analysis; the few discrepancies can be explained by blending issues in the earlier lower-resolution Spitzer data. At z~2.5, the resolved rest-frame near-infrared (1.6 micron) structure of the galaxies is significantly more smooth and centrally concentrated than seen by HST at rest-frame 450 nm (F160W), with effective radii of Re(F560W)=1-5 kpc and S\'ersic indices mostly close to an exponential (disk-like) profile (n~1), up to n~5 (excluding AGN). We find an average size ratio of Re(F560W)/Re(F160W)~0.7 that decreases with stellar mass. The stellar structure of the ALMA-selected galaxies is indistinguishable from a HUDF reference sample of galaxies with comparable MIRI flux density. We supplement our analysis with custom-made, position-dependent, empirical PSF models for the F560W observations. The results imply that a smoother stellar structure is in place in massive gas-rich, star-forming galaxies at Cosmic Noon, despite a more clumpy rest-frame optical appearance, placing additional constraints on galaxy formation simulations. As a next step, matched-resolution, resolved ALMA observations will be crucial to further link the mass- and light-weighted galaxy structures to the dusty interstellar medium., Comment: 19 pages, 12 figures, 1 table, Accepted for publication in ApJ

We present a JWST/MRS spectrum of the quasar J1120+0641 at z=7.0848, the first spectroscopic observation of a reionisation-era quasar in the rest-frame infrared ($0.6<\lambda<3.4\mu$m). In the context of the mysterious fast assembly of the first supermassive black holes at z>7, our observations enable for the first time the detection of hot torus dust, the H$\alpha$ emission line, and the Paschen-series broad emission lines in a quasar at z>7. Hot torus dust is clearly detected as an upturn in the continuum emission at $\lambda_{\text{rest}}\simeq1.3\mu$m, leading to a black-body temperature of $T=1413.5^{+5.7}_{-7.4}$K. Compared to similarly-luminous quasars at 06 ($2\sigma$ significance). We measure the black hole mass of J1120+0641 based on the H$\alpha$ Balmer line, $M_{\text{BH}}=1.52\pm0.17\cdot 10^9 M_\odot$, which is in good agreement with the previous rest-UV MgII black hole mass measurement. The black hole mass based on the Paschen-series lines is also consistent, indicating no significant extinction in the rest-frame UV measurement. The broad H$\alpha$, Pa-$\alpha$ and Pa-$\beta$ emission lines are consistent with an origin in a common broad-line region (BLR) with density log$N_H/\text{cm}^{-3}\geq 12$, ionisation parameter $-7<$log$U<-4$, and extinction E(B-V)$\lesssim 0.1$mag. These BLR parameters are consistent with similarly-bright quasars at 0

We present the ultraviolet luminosity function and an estimate of the cosmic star formation rate density at $88$ galaxy candidates based on their dropout nature in the F115W and/or F150W filters, a high probability for their photometric redshifts, estimated with three different codes, being at $z>8$, good fits based on $\chi^2$ calculations, and predominant solutions compared to $z<8$ alternatives. We find mild evolution in the luminosity function from $z\sim13$ to $z\sim8$, i.e., only a small increase in the average number density of $\sim$0.2 dex, while the faint-end slope and absolute magnitude of the knee remain approximately constant, with values $\alpha=-2.2\pm0.1$ and $M^*=-20.8\pm0.2$ mag. Comparing our results with the predictions of state-of-the-art galaxy evolution models, we find two main results: (1) a slower increase with time in the cosmic star formation rate density compared to a steeper rise predicted by models; (2) nearly a factor of 10 higher star formation activity concentrated in scales around 2 kpc in galaxies with stellar masses $\sim10^8$ M$_\odot$ during the first 350 Myr of the Universe, $z\sim12$, with models matching better the luminosity density observational estimations $\sim$150 Myr later, by $z\sim9$., Comment: Accepted for publication in ApJL, in memoriam Hans Ulrik Noorgaard-Nielsen and Olivier Le F\`evre

Large fractions of metals are missing from the observable gas-phase in the interstellar medium (ISM) because they are incorporated into dust grains, a phenomenon called dust depletion. The study of dust depletion in the ISM is important to investigate the origin and evolution of metals and cosmic dust. Here we aim at characterizing the dust depletion of several metals from the Milky Way to distant galaxies. We collect ISM metal column densities from absorption-line spectroscopy in the literature, and in addition, we determine Ti and Ni column densities from a sample of 70 damped Lyman-$\alpha$ absorbers (DLAs) towards quasars, observed with UVES/VLT. We use ISM relative abundances to estimate the dust depletion of 18 metals (C, P, O, Cl, Kr, S, Ge, Mg, Si, Cu, Co, Mn, Cr, Ni, Al, Ti, Zn and Fe) for different environments (the Milky Way, the Magellanic Clouds (MCs), DLAs towards quasars and towards gamma-ray bursts). We observe linear relations between the depletion of each metal and the strength of dust depletion, which we trace with the observed [Zn/Fe]. In the neutral ISM of the MCs we find small deviations from linearity observed as an overabundance of the $\alpha$-elements Ti, Mg, S and an underabundance of Mn. The deviations disappear if we assume that all OB stars observed towards the MCs in our sample have an $\alpha$-element enhancement and Mn underabundance. This may imply that the MCs have been recently enriched in $\alpha$-elements, potentially due to recent bursts of star formation. The observed strong correlations of the depletion sequences of the metals all the way from low metallicity QSO-DLAs to the Milky Way suggest that cosmic dust has a common origin, independently of the star formation history, which varies significantly between these different galaxies. This supports the importance of grain growth in the ISM as a significant process of dust production., Comment: 30 pages, 35 figures, 12 tables, Accepted for publication in A&A, Abstract abridged for arXiv