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The first observations of JWST have revolutionized our understanding of the Universe by identifying for the first time galaxies at $z\sim13$. In addition, the discovery of many luminous galaxies at Cosmic Dawn ($z>10$) has suggested that galaxies developed rapidly, in apparent tension with many standard models. However, most of these galaxies lack spectroscopic confirmation, so their distances and properties are uncertain. We present JADES JWST/NIRSpec spectroscopic confirmation of two luminous galaxies at redshifts of $z=14.32^{+0.08}_{-0.20}$ and $z=13.90\pm0.17$. The spectra reveal ultraviolet continua with prominent Lyman-$\alpha$ breaks but no detected emission lines. This discovery proves that luminous galaxies were already in place 300~million years after the Big Bang and are more common than what was expected before JWST. The most distant of the two galaxies is unexpectedly luminous and is spatially resolved with a radius of 260 parsecs. Considering also the very steep ultraviolet slope of the second galaxy, we conclude that both are dominated by stellar continuum emission, showing that the excess of luminous galaxies in the early Universe cannot be entirely explained by accretion onto black holes. Galaxy formation models will need to address the existence of such large and luminous galaxies so early in cosmic history., Comment: 15 figures, 3 tables, published in Nature

The James Webb Space Telescope (JWST) has spectroscopically confirmed numerous galaxies at $z > 10$. While weak rest-ultraviolet emission lines have only been seen in a handful of sources, the stronger rest-optical emission lines are highly diagnostic and accessible at mid-infrared wavelengths with the Mid-Infrared Instrument (MIRI) of JWST. We report the photometric detection of the most distant spectroscopically confirmed galaxy JADES-GS-z14-0 at $z = 14.32^{+0.08}_{-0.20}$ with MIRI at $7.7\ \mu\mathrm{m}$. The most plausible solution for the stellar population properties is that this galaxy contains half a billion solar masses in stars with a strong burst of star formation in the most recent few million years. For this model, at least one-third of the flux at $7.7\ \mu\mathrm{m}$ comes from the rest-optical emission lines $\mathrm{H}\beta$ and/or $\mathrm{[OIII]}\lambda\lambda4959,5007$. The inferred properties of JADES-GS-z14-0 suggest rapid mass assembly and metal enrichment during the earliest phases of galaxy formation., Comment: Submitted; main text has 9 pages, 3 figures and 1 table; extended text has 15 pages, 5 figures, and 1 table

The peculiar nebular emission displayed by galaxies in the early Universe presents a unique opportunity to gain insight into the regulation of star formation in extreme environments. We investigate 500 (109) galaxies with deep NIRSpec/PRISM observations from the JADES survey at $z>2$ ($z>5.3$), finding 52 (26) galaxies with Balmer line ratios more than $1\sigma$ inconsistent with Case B recombination. These anomalous Balmer emitters (ABEs) cannot be explained by dust attenuation, indicating a departure from Case B recombination. To address this discrepancy, we model density-bounded nebulae with the photoionisation code CLOUDY. Density-bounded nebulae show anomalous Balmer line ratios due to Lyman line pumping and a transition from the nebulae being optically thin to optically thick for Lyman lines with increasing cloud depth. The H$\alpha$/H$\beta$ versus H$\gamma$/H$\beta$ trend of density-bounded models is robust to changes in stellar age of the ionising source, gas density, and ionisation parameter; however, increasing the stellar metallicity drives a turnover in the trend. This is due to stronger stellar absorption features around Ly$\gamma$ reducing H$\beta$ fluorescence, allowing density-bounded models to account for all observed Balmer line ratios. ABEs show higher [OIII]/[OII], have steeper ultra-violet slopes, are fainter, and are more preferentially Ly$\alpha$ emitters than galaxies which are consistent with Case B and little dust. These findings suggest that ABEs are galaxies that have become density bounded during extreme quenching events, representing a transient phase of $\sim$20 Myr during a fast breathing mode of star formation., Comment: 12 pages, 9 figures, submitted to MNRAS, comments welcome

We present observations of the $z\sim5.7$ Lyman-break galaxy HZ10 with the JWST/NIRSpec IFU in high and low spectral resolution (G395H, $R\sim2700$ and PRISM, $R\sim100$, respectively), as part of the GA-NIFS program. By spatially resolving the source, we find evidence for three spatially and spectrally distinct regions of line emission along with one region of strong continuum emission, all within a projected distance of $<10$kpc. The R2700 data features strong detections in H$\beta$, [OIII]$\lambda\lambda4959{,}5007$, [NII]$\lambda\lambda6548{,}6584$, H$\alpha$, and [SII]$\lambda\lambda6716{,}6731$. The R100 data additionally contains a strong detection of the Ly$\alpha$ break, rest-UV continuum, and [OII]$\lambda\lambda3726{,}3729$. None of the detected lines present strong evidence for AGN excitation from line diagnostic diagrams, and no high-ionisation lines are detected. Using the detected lines, we constrain the electron density $\left( \rm \log_{10}\left( n_e / cm^{-3}\right)\sim2.5-3.3\right)$ and metallicity ($\sim0.5-0.7$ solar) in each component. Spaxel-by-spaxel fits of each cube reveal a strong east-west velocity gradient and significant line asymmetries (indicating tidal features or outflows). The western component features a very red UV slope ($\beta_{UV}\sim-1$) and significant H$\alpha$ emission, suggesting an evolved population and active star formation. From a comparison to high resolution [CII]$158\mu$m imaging obtained with the Atacama Large Millimetre/submillimetre Array (ALMA), we find that the continuum emitter is associated with a gas-poor stellar population. Altogether, these data suggest that HZ10 represents an ongoing merger, with a complex distribution of stars, gas, and dust $<1$Gyr after the Big Bang., Comment: 16 pages, 11 figures. Submitted to MNRAS

Observations of transiting gas giant exoplanets have revealed a pervasive depletion of methane, which has only recently been identified atmospherically. The depletion is thought to be maintained by disequilibrium processes such as photochemistry or mixing from a hotter interior. However, the interiors are largely unconstrained along with the vertical mixing strength and only upper limits on the CH$_4$ depletion have been available. The warm Neptune WASP-107 b stands out among exoplanets with an unusually low density, reported low core mass, and temperatures amenable to CH$_4$ though previous observations have yet to find the molecule. Here we present a JWST NIRSpec transmission spectrum of WASP-107 b which shows features from both SO$_2$ and CH$_4$ along with H$_2$O, CO$_2$, and CO. We detect methane with 4.2$\sigma$ significance at an abundance of 1.0$\pm$0.5 ppm, which is depleted by 3 orders of magnitude relative to equilibrium expectations. Our results are highly constraining for the atmosphere and interior, which indicate the envelope has a super-solar metallicity of 43$\pm$8$\times$ solar, a hot interior with an intrinsic temperature of T$_{\rm int}$=460$\pm$40 K, and vigorous vertical mixing which depletes CH4 with a diffusion coefficient of Kzz = 10$^{11.6\pm0.1}$ cm$^2$/s. Photochemistry has a negligible effect on the CH$_4$ abundance, but is needed to account for the SO$_2$. We infer a core mass of 11.5$_{-3.6}^{+3.0}$ M$_{\odot}$, which is much higher than previous upper limits, releasing a tension with core-accretion models., Comment: Published in Nature at this URL, https://www.nature.com/articles/s41586-024-07395-z . This is the authors version of the manuscript, 20 pages including Methods. Data from Figs. 1, 2, and 3 are available at this URL, https://doi.org/10.5281/zenodo.10891400

We report the detection of continuum excess in the rest-frame UV between 3000 {\AA} and 3550 {\AA} in the JWST/NIRSpec spectrum of GN-z11, a galaxy hosting an active galactic nucleus (AGN) at z = 10.603. The shape of the continuum excess resembles a Balmer continuum but has a break around 3546 {\AA} in the rest frame, which is 100 {\AA} bluewards to the Balmer limit at 3646 {\AA}. A Balmer continuum model alone cannot fit the spectrum, implying a different origin for the continuum excess. The absence of the Balmer jump indicates an electron temperature of $\sim 3\times 10^4$ K, which is significantly higher than the temperature of $T_{e}({\rm O^{2+}}) \approx 1.3\times 10^{4}$ K inferred from [OIII]$\lambda 4363$. The temperature difference must result from mixing of different ionized regions: the Balmer emission mainly arises from dense and hot clouds in the Broad Line Region, close to the accreting black hole, whereas the forbidden lines originate from less dense and colder gas in the host galaxy (although these ionized regions are kinematically similar in GN-z11 due to its small BH mass). We propose a potential explanation for the observed continuum excess to come from a complex of FeII emission, which shows a characteristic jump bluewards to the Balmer limit as previously seen in the spectra of many lower-redshift quasars. Through comparisons with Cloudy models, we show an Fe abundance or an overall metallicity above $\sim 1/3$ solar is likely needed. Besides the FeII emission, part of the small blue bump might also be associated with an OIII Bowen fluorescent line, a line often enhanced in dense AGN-ionized gas. Finally, the spectrum provides further evidence against Wolf-Rayet or massive stars dominating the nebular emission in GN-z11., Comment: 22 pages (including appendix), 18 figures, submitted to MNRAS

Feedback is the key physical mechanism regulating galaxy formation. Stars in galaxies form when baryons radiatively cool down and fall into gravitational wells. Eventually, star formation quenches as gas is depleted and/or perturbed by feedback processes, no longer being able to collapse and condense. For massive galaxies, astronomers identify feedback from accreting supermassive black holes (active galactic nuclei, AGN) as the main agent responsible for quenching. We report the first spatially resolved spectroscopic observations of a massive, completely quiescent galaxy at $z=3.714$ (Jekyll) and its neighborhood. Jekyll is part of a galaxy pair with a compact, dusty, massive star-forming companion (Hyde). We find large amounts of ionized and neutral gas in the intergalactic medium around the pair, yet Jekyll has remained quiescent for more than 500~Myr. The emitting gas is consistent with AGN photoionization, but no AGN is observed in Jekyll. We find that, in contrast to standard scenarios, AGN in satellite galaxies can be critical contributors for keeping massive galaxies quiescent in the early Universe. After the accelerated formation and quenching of the massive central galaxy, tidally induced gas stripping additionally contributes to the star-formation regulation on subsequent satellite galaxy generations., Comment: Submitted. Comments welcome

We investigate the X-ray properties of a sample of 71 broad line and narrow line AGN at 2$<$z$<$11 discovered by JWST in the GOODS fields, which have the deepest Chandra observations ever obtained. Despite the widespread presence of AGN signatures in their rest-optical and -UV spectra, the vast majority of them is X-ray undetected. The stacked X-ray data of the non-detected sources also results in a non-detection. The upper limit on the X-ray emission for many of these AGN is one or even two orders of magnitude lower than expected from a standard AGN SED. X-ray absorption by clouds with large (Compton-thick) column density and low dust content, such as the Broad Line Region (BLR) clouds, can explain the X-ray weakness. In this scenario the BLR covering factor should be much larger than in low-z AGN or luminous quasars; this is supported by the larger equivalent width of the broad component of H$\alpha$ in JWST-selected AGN. We also find that the JWST-discovered AGN lack prominent, fast outflows, suggesting that, in JWST-selected AGN, dense gas lingers in the nuclear region, resulting in large covering factors. We also note that a large fraction of JWST-selected AGN matches the definition of NLSy1, typically accreting at high rates and characterized by a steep X-ray spectrum -- this can further contribute to their observed weakness at high-z. Finally, we discuss that the broad Balmer lines used to identify type 1 AGN cannot be ascribed to Very Massive Stars or Supernovae, although we show that some of the faintest broad lines could potentially be associated with superluminous SNe., Comment: 21 pages, 15 figures, 2 tables, resubmitted to MNRAS after responding to the referee's comments

The amount of power contained in the variations in galaxy star-formation histories (SFHs) across a range of timescales encodes key information about the physical processes which modulate star formation. Modelling the SFHs of galaxies as stochastic processes allows the relative importance of different timescales to be quantified via the power spectral density (PSD). In this paper, we build upon the PSD framework and develop a physically-motivated, "stochastic" prior for non-parametric SFHs in the spectral energy distribution (SED)-modelling code Prospector. We test this prior in two different regimes: 1) massive, $z = 0.7$ galaxies with both photometry and spectra, analogous to those observed with the LEGA-C survey, and 2) $z = 8$ galaxies with photometry only, analogous to those observed with NIRCam on JWST. We find that it is able to recover key galaxy parameters (e.g. stellar mass, stellar metallicity) to the same level of fidelity as the commonly-used continuity prior. Furthermore, the realistic variability information incorporated by the stochastic SFH model allows it to fit the SFHs of galaxies more accurately and precisely than traditional non-parametric models. In fact, the stochastic prior is $\gtrsim 2\times$ more accurate than the continuity prior in measuring the recent star-formation rates (log SFR$_{100}$ and log SFR$_{10}$) of both the $z = 0.7$ and $z = 8$ mock systems. While the PSD parameters of individual galaxies are difficult to constrain, the stochastic prior implementation presented in this work allows for the development hierarchical models in the future, i.e. simultaneous SED-modelling of an ensemble of galaxies to measure their underlying PSD., Comment: Comments welcome!

The James Webb Space Telescope (JWST) is revolutionizing our understanding of black holes formation and growth in the early Universe. However, JWST has also revealed that some of the classical diagnostics, such as the BPT diagrams and X-ray emission, often fail to identify narrow line TypeII active galactic nuclei (AGN) at high redshift. Here we present three new rest-frame optical diagnostic diagrams leveraging the [OIII]$\lambda4363$ auroral line, which has been detected in several JWST spectra. Specifically, we show that high values of the [OIII]$\lambda4363/$H$\gamma$ ratio provide a sufficient (but not necessary) condition to identify the presence of an AGN, both based on empirical calibrations (using local and high-redshift sources) and a broad range of photoionization models. These diagnostics are able to separate much of the AGN population from Star Forming Galaxies (SFGs). This is because the average energy of AGN's ionizing photons is higher than that of young stars in SFGs, hence AGN can more efficiently heat the gas, therefore boosting the [OIII]$\lambda4363$ line. We also found independent indications of AGN activity in some high-redshift sources that were not previously identified as AGN with the traditional diagnostics diagrams, but that are placed in the AGN region of the diagnostics presented in this work. We note that, conversely, low values of [OIII]$\lambda4363/$H$\gamma$ can be associated either with SFGs or AGN excitation. We note that the fact that strong auroral lines are often associated with AGN does not imply that they cannot be used for direct metallicity measurements (provided that proper ionization corrections are applied), but it does affect the calibration of strong line metallicity diagnostics., Comment: Accepted for publication in A&A. 16 pages, 7 figures

We present a detailed study of the centre of NGC4654, a Milky Way-like spiral galaxy in the Virgo cluster that has been reported to host a double stellar nucleus, thus promising a rare view of ongoing star cluster infall into a galaxy nucleus. Analysing JWST NIRSpec integral-field spectroscopic data and Hubble Space Telescope imaging of the inner 330 $\times$ 330 pc, we find that the nucleus harbours in fact three massive star clusters. Maps of infrared emission lines from NIRSpec show different morphologies for the ionised and molecular gas components. The emission from molecular hydrogen gas is concentrated at the NSC location, while emission from hydrogen recombination lines is more extended beyond the central cluster. The velocity fields of both gas and stars indicate that the three clusters are part of a complicated dynamical system, with the NSC having an elevated velocity dispersion in line with its high stellar mass. To investigate the stellar populations of the three clusters in more detail, we use surface brightness modelling to measure their fluxes from ultraviolet to mid-infrared wavelengths and fit their spectral energy distributions (SEDs). Two of the clusters are UV-bright and well described by single stellar populations with young ages ($\sim$ 3 and 5 Myr) and low masses ($M_\ast \sim 4 \times 10^{4} - 10^{5} M_\odot$), whereas the central cluster is much more massive ($3 \times 10^7 M_\odot$), and cannot be fitted by a single stellar population. Instead, we find that a minor young population ($\sim$ 1 Myr) embedded in a dominant old population ($\sim$ 8 Gyr) is needed to explain its SED. Given its complex composition and the close proximity of two young star clusters that are likely to merge with it within a few hundred million years, we consider NGC4654 a unique laboratory to study NSC growth from both in-situ star formation and the infall of star clusters., Comment: Main text: 13 pages, 8 figures, accepted for publication in A&A

We present the third data release of JADES, the JWST Advanced Deep Extragalactic Survey, providing both imaging and spectroscopy in the two GOODS fields. Spectroscopy consists of medium-depth and deep NIRSpec/MSA spectra of 4,000 targets, covering the spectral range 0.6-5.3 $\mu$m and observed with both the low-dispersion prism (R=30-300) and all three medium-resolution gratings (R=500-1,500). We describe the observations, data reduction, sample selection, and target allocation. We measured 2,375 redshifts (2,053 from multiple emission lines); our targets span the range from z=0.5 up to z=13, including 404 at z>5. The data release includes 2-d and 1-d fully reduced spectra, with slit-loss corrections and background subtraction optimized for point sources. We also provide redshifts and S/N>5 emission-line flux catalogs for the prism and grating spectra, and concise guidelines on how to use these data products. Alongside spectroscopy, we are also publishing fully calibrated NIRCam imaging, which enables studying the JADES sample with the combined power of imaging and spectroscopy. Together, these data provide the largest statistical sample to date to characterize the properties of galaxy populations in the first billion years after the Big Bang., Comment: 41 pages, 26 figures, 10 tables. Submitted to ApJS

$\require{mediawiki-texvc}$Given the sensitivity of the resonant Lyman-$\mathrm{\alpha}$ (Ly$\mathrm{\alpha}$) transition to absorption by neutral hydrogen, observations of Ly$\mathrm{\alpha}$ emitting galaxies (LAEs) have been widely used to probe the ionising capabilities of reionisation-era galaxies and their impact on the intergalactic medium (IGM). However, prior to JWST our understanding of the contribution of fainter sources and of ionised `bubbles' at earlier stages of reionisation remained uncertain. Here, we present the characterisation of three exceptionally distant LAEs at $z>8$, newly discovered by JWST/NIRSpec in the JADES survey. These three similarly bright ($M_\text{UV} \approx -20\,\mathrm{mag}$) LAEs exhibit small Ly$\mathrm{\alpha}$ velocity offsets from the systemic redshift, $\Delta v_\mathrm{Ly\alpha} \lesssim 200\,\mathrm{km\,s^{-1}}$, yet span a range of Ly$\mathrm{\alpha}$ equivalent widths ($15\,\AA$, $31\,\AA$, and $132\,\AA$). The former two show moderate Ly$\mathrm{\alpha}$ escape fractions ($f_\mathrm{esc,Ly\alpha} \approx 10\%$), whereas Ly$\mathrm{\alpha}$ escapes remarkably efficiently from the third ($f_\mathrm{esc,Ly\alpha} \approx 72\%$), which moreover is very compact (half-light radius of $90\pm10\,\mathrm{pc}$). We find these LAEs are low-mass galaxies dominated by very recent, vigorous bursts of star formation accompanied by strong nebular emission from metal-poor gas. We infer the two LAEs with modest $f_\mathrm{esc,Ly\alpha}$, one of which reveals evidence for ionisation by an active galactic nucleus, may have reasonably produced small ionised bubbles preventing complete IGM absorption of Ly$\mathrm{\alpha}$. The third, however, requires a $\sim 3\,\text{physical Mpc}$ bubble, indicating faint galaxies have contributed significantly. The most distant LAEs thus continue to be powerful observational probes into the earlier stages of reionisation., Comment: 25 pages, 13 figures, accepted for publication in MNRAS

We describe new ultra-deep James Webb Space Telescope (JWST) NIRSpec PRISM and grating spectra for the galaxies JADES-GS-z11-0 ($z_{\mathrm{spec}} = 11.122^{+0.005}_{-0.003}$) and JADES-GS-z13-0 ($z_{\mathrm{spec}} = 13.20^{+0.03}_{-0.04}$), the most distant spectroscopically-confirmed galaxy discovered in the first year of JWST observations. The extraordinary depth of these observations (75 hours and 56 hours, respectively) provides a unique opportunity to explore the redshifts, stellar properties, UV magnitudes, and slopes for these two sources. For JADES-GS-z11-0, we find evidence for multiple emission lines, including [\ion{O}{2}]$\lambda\lambda3726,3729$\AA and [\ion{Ne}{3}$]\lambda3869$\AA, resulting in a spectroscopic redshift we determine with 94\% confidence. We present stringent upper limits on the emission line fluxes and line equivalent widths for JADES-GS-z13-0. At this spectroscopic redshift, the Lyman-$\alpha$ break in JADES-GS-z11-0 can be fit with a damped Lyman-$\alpha$ absorber with $\log{(N_\mathrm{HI}/\mathrm{cm}^{-2})} = 22.42^{+0.093}_{-0.120}$. These results demonstrate how neutral hydrogen fraction and Lyman-damping wings may impact the recovery of spectroscopic redshifts for sources like these, providing insight into the overprediction of the photometric redshifts seen for distant galaxies observed with JWST. In addition, we analyze updated NIRCam photometry to calculate the morphological properties of these resolved sources, and find a secondary source $0.3^{\prime\prime}$ south of JADES-GS-z11-0 at a similar photometric redshift, hinting at how galaxies grow through interactions in the early Universe., Comment: 34 pages, 19 figures, accepted for publication in The Astrophysical Journal (September 30, 2024)

We report the chemical abundance pattern of GS\_3073, a galaxy at $z=5.55$ which was previously confirmed to host an overmassive active black hole, by leveraging the detection of about 40 emission lines, combining JWST/NIRSpec observations and ground-based (VLT/VIMOS) data. Based on the rest-frame UV emission lines, which trace high-density ($\sim 10^5~{\rm cm}^{-3}$) and highly ionized gas, we derived an abundance ratio of $\rm log(N/O) = 0.42^{+0.13}_{-0.10}$. At an estimated metallicity of $0.2~Z_{\odot}$, this is the most extreme nitrogen-rich object found by JWST thus far. In comparison, the relative carbon abundance derived from the rest-frame UV emission lines is $\rm log(C/O) = -0.38^{+0.13}_{-0.11}$, which is not significantly higher than those in local galaxies and stars with similar metallicities. We also found potential detection of coronal lines including [FeVII]$\lambda 6087$ and [FeXIV]$\lambda 5303$, both blended with [CaV]. We inferred a range of Fe abundances compatible with those in local stars and galaxies. Overall, the chemical abundance pattern of GS\_3073 is compatible with enrichment by super-massive stars with $M_* \gtrsim 1000~M_\odot$, asymptotic giant branch (AGB) stars, or Wolf-Rayet (WR) stars. Interestingly, when using optical emission lines which trace lower density ($\sim 10^3~{\rm cm}^{-3}$) and lower ionization gas, we found a sub-solar N/O ratio. We interpret the difference in N/O derived from UV lines and optical lines as evidence for a stratified system, where the inner and denser region is both more chemically enriched and more ionized. Taking this luminous, well-studied system as a benchmark, our results suggest that nitrogen loudness in high-$z$ galaxies is confined to the central, dense, and highly ionized region of the galaxies, while the bulk of the galaxies evolves more normally., Comment: 28 pages, 15 figures, accepted for publication in MNRAS

Understanding the sources that power nebular emission in high-redshift galaxies is fundamentally important not only for shedding light onto the drivers of reionisation, but to constrain stellar populations and the growth of black holes. Here we focus on an individual object, GS9422, a galaxy at $z_{\rm spec}=5.943$ with exquisite data from the JADES and JEMS surveys, including 14-band JWST/NIRCam photometry and deep NIRSpec prism and grating spectroscopy. We map the continuum emission and nebular emission lines across the galaxy on 0.2-kpc scales. GS9422 has been claimed to have nebular-dominated continuum and an extreme stellar population with top-heavy initial mass function. We find clear evidence for different morphologies in the emission lines, the rest-UV and rest-optical continuum emission, demonstrating that the full continuum cannot be dominated by nebular emission. While multiple models reproduce the spectrum reasonably well, our preferred model with a type-2 active galactic nucleus (AGN) and local damped Ly-$\alpha$ (DLA) clouds can explain both the spectrum and the wavelength-dependent morphology. The AGN powers the off-planar nebular emission, giving rise to the Balmer jump and the emission lines, including Ly-$\alpha$, which therefore does not suffer DLA absorption. A central, young stellar component dominates the rest-UV emission and -- together with the DLA clouds -- leads to a spectral turn-over. A disc-like, older stellar component explains the flattened morphology in the rest-optical continuum. We conclude that GS9422 is consistent with being a normal galaxy with an obscured, type-2 AGN -- a simple scenario, without the need for exotic stellar populations., Comment: 19 pages, 13 figures, submitted to MNRAS. Comments welcome

Arp 220 is the nearest ULIRG; it shows evidence of 100 pc-scale molecular outflows likely connected with galaxy-scale outflows traced by ionised and neutral gas. The two highly obscured nuclei of Arp 220 are the site of intense star formation, with extreme star-formation rate surface densities (~ 10^3 Msun/yr/kpc2). Despite extensive investigations searching for AGN activity in the Arp 220 nuclei, direct evidence remains elusive. We present JWST/NIRSpec IFS observations covering the 0.9 - 5.1 um wavelength range of the innermost (5''x4'', i.e. 1.8x1.5 kpc) regions of Arp 220. The primary goal is to investigate the potential presence of AGN signatures in the nuclear regions by analysing the spectra extracted from circular apertures of radius 55 pc (0.15'') around each of the two nuclei. We identify ~ 70 ionised and ~ 50 molecular emission lines in the nuclear spectra of Arp 220; we use recombination line ratios to measure optical extinctions in the range AV ~ 11 - 14 mag. High ionisation lines are not detected, except the [Mg IV] line at 4.49 um which we interpret as due to shocks rather than to AGN ionisation. We identify broadening and multiple kinematic components in the HI and H2 lines caused by outflows and shocks, with velocities up to ~ 550 km/s. Significantly higher velocities (up to ~ 900 km/s) are detected in the off-nuclear regions; however, they do not conclusively represent evidence for AGN activity. Even with the unprecedented sensitivity of JWST/NIRSpec IFS, achieving an unambiguous identification or exclusion of the presence of an AGN in the Arp 220 system remains challenging, because of its extreme dust obscuration., Comment: submitted to A&A, comments welcome

The detection of blue-shifted absorption lines likely associated with ionized Iron K-shell transitions in the X-ray spectra of many Active Galactic Nuclei (AGN) suggests the presence of a highly ionized gas outflowing with mildly relativistic velocities (0.03c-0.6c), named Ultra-Fast Outflow (UFO). Within the SUBWAYS project we characterized these winds starting from a sample of 22 radio-quiet quasars at 0.1 < z < 0.4, and compared the results with similar studies in the literature on samples of 42 local radio-quiet Seyfert galaxies and 14 high redshift radio-quiet quasars. The scope of our work is a statistical study of UFO parameters and incidence, considering key physical properties of the sources, e.g. supermassive black hole (SMBH) mass, bolometric luminosity, accretion rates and Spectral Energy Distribution, with the aim of gaining new insights into the UFO launching mechanisms. We find indications that highly luminous AGN with steeper X-ray/UV ratio, are more likely to host UFO. The presence of UFO is not significantly related to any other AGN property in our sample. These findings suggest that the UFO phenomenon may be transient. Focusing on AGN with UFO, other important results are: (1) faster UFO have larger ionization parameters and column densities; (2) X-ray radiation plays a more crucial role in driving highly ionized winds compared to UV; (3) the correlation between outflow velocity and luminosity is significantly flatter than what expected for radiatively driven winds; (4) more massive BH experience higher wind mass-losses, suppressing accretion of matter onto the BH; (5) the UFO launching radius is positively correlated with the Eddington ratio. Furthermore, our analysis suggest the involvement of multiple launching mechanisms, including radiation pressure and magneto-hydrodynamic processes, rather than pointing to a single, universally applicable mechanism., Comment: 52 pages, 154 figures and 7 tables. Accepted in Astronomy & Astrophysics, in press

We present the first statistical investigation of spatially resolved emission-line properties in a sample of 63 low-mass galaxies at $4\leq z<10$, using JWST/NIRSpec MSA data from the JWST Advanced Deep Extragalactic (JADES) survey focusing on deep, spatially resolved spectroscopy in the GOODS-S extragalactic field. By performing a stacking of the 2D spectra of the galaxies in our sample, we find an increasing or flat radial trend with increasing radius for [OIII]$\lambda5007$/H$\beta$ and a decreasing one for [NeIII]$\lambda3869$/[OII]$\lambda3727$ (3--4 $\sigma$ significance). These results are still valid when stacking the sample in two redshift bins (i.e., $4\leq z<5.5$ and $5.5\leq z<10$). The comparison with star-formation photoionization models suggests that the ionization parameter increases by $\sim 0.5$ dex with redshift. We find a tentative metallicity gradient that increases with radius (i.e., 'inverted') in both redshift bins. Moreover, our analysis reveals strong negative gradients for the equivalent width of \Hbeta (7$\sigma$ significance). This trend persists even after removing known AGN candidates, therefore, it is consistent with a radial gradient primarily in stellar age and secondarily in metallicity. Taken all together, our results suggest that the sample is dominated by active central star formation, with possibly inverted metallicity gradients sustained by recent episodes of accretion of pristine gas or strong radial flows. Deeper observations and larger samples are needed to confirm these preliminary results and to validate our interpretation., Comment: 15 pages, 13 Figures, 1 Table. Submitted to A&A

The Near-infrared Spectrograph (NIRSpec) on the James Webb Space Telescope is uniquely suited to studying galaxies in the distant Universe with its combination of multi-object capabilities and sensitivity over a large range in wavelength (0.6-5.3 microns). Here we present the NIRSpec Wide survey, part of the NIRSpec Instrument Science Team's Guaranteed Time Observations, using NIRSpec's microshutter array to obtain spectra of more than 3200 galaxies at $z>1$ at both low- and high-resolution ($R\approx100$ and 2700) for a total of 105 hours. With 31 pointings covering $\approx$320 arcmin$^2$ across the five CANDELS fields with exquisite ancillary photometry from the Hubble Space Telescope, the NIRSpec Wide survey represents a fast and efficient way of using JWST to probe galaxies in the early Universe. Pointing centers are determined to maximize the observability of the rarest, high-value sources. Subsequently, the microshutter configurations are optimized to observe the maximum number of "census" galaxies with a selection function based primarily on HST/F160W magnitude, photometric/slitless grism redshift, and predicted \ha\ flux tracing the bulk of the galaxy population at cosmic noon ($z_{\rm med}=2.0$). We present details on the survey strategy, the target selection, an outline of the motivating science cases, and discuss upcoming public data releases to the community., Comment: Published in A&A. Data for pointings in AEGIS available for download at https://archive.stsci.edu/hlsp/wide (https://archive.stsci.edu/hlsps/wide/download_scripts/hlsp_wide_jwst_nirspec_all_multi_v1.0_spec-download.sh)

The study of gas-phase metallicity and its spatial distribution at high redshift is crucial to understand the processes that shaped the growth and evolution of galaxies in the early Universe. Here we study the spatially resolved metallicity in three systems at $z\sim6-8$, namely A2744-YD4, BDF-3299, and COSMOS24108, with JWST NIRSpec IFU low-resolution ($R\sim100$) spectroscopic observations. These are among the highest-$z$ sources in which metallicity gradients have been probed so far. Each of these systems hosts several spatial components in the process of merging within a few kpc, identified from the rest-frame UV and optical stellar continuum and ionised gas emission line maps. The sources have heterogeneous properties, with stellar masses log($M_*/M_\odot) \sim 7.6-9.3$, star formation rates (SFRs) $\sim1-15$ $M_\odot$ yr$^{-1}$, and gas-phase metallicities 12+log(O/H) $\sim 7.7-8.3$, which exhibit a large scatter within each system. Their properties are generally consistent with those of the highest-$z$ samples to date ($z\sim3-10$), though the sources in A2744-YD4 and COSMOS24108 are at the high end of the mass-metallicity relation (MZR) defined by the $z\sim3-10$ sources. Moreover, the targets in this work follow the predicted slope of the MZR at $z\sim 6-8$ from most cosmological simulations. The gas-phase metallicity gradients are consistent with being flat in the main sources of each system. Flat metallicity gradients are thought to arise from gas mixing processes on galaxy scales, such as mergers or galactic outflows and SN winds driven by intense stellar feedback, which wash out any gradient formed in the galaxy. The existence of flat gradients at $z\sim6-8$ sets also important constraints on cosmological simulations and chemical evolution models, whose predictions on the cosmic evolution of metallicity gradients differ significantly, but are mostly limited to $z<3$ so far., Comment: 15 pages (+5 appendix); 7 figures (+8 in appendix); in production on A&A

We present an analysis of the diffuse ionised gas (DIG) in a high-resolution simulation of an isolated Milky Way-like galaxy, incorporating on-the-fly radiative transfer and non-equilibrium thermochemistry. We utilise the Monte-Carlo radiative transfer code COLT to self-consistently obtain ionisation states and line emission in post-processing. We find a clear bimodal distribution in the electron densities of ionised gas ($n_{\rm e}$), allowing us to define a threshold of $n_{\rm e}=10\,\mathrm{cm}^{-3}$ to differentiate DIG from HII regions. The DIG is primarily ionised by stars aged 5-25 Myr, which become exposed directly to low-density gas after HII regions have been cleared. Leakage from recently formed stars ($<5$ Myr) is only moderately important for DIG ionisation. We forward model local observations and validate our simulated DIG against observed line ratios in [SII]/H$\alpha$, [NII]/H$\alpha$, [OI]/H$\alpha$, and [OIII]/H$\beta$ against $\Sigma_{\rm H\alpha}$. The mock observations not only reproduce observed correlations, but also demonstrate that such trends are related to an increasing temperature and hardening ionising radiation field with decreasing $n_{\rm e}$. The hardening of radiation within the DIG is caused by the gradual transition of the dominant ionising source with decreasing $n_{\rm e}$ from 0 Myr to 25 Myr stars, which have progressively harder intrinsic ionising spectra primarily due to the extended Wolf-Rayet phase caused by binary interactions. Consequently, the DIG line ratio trends can be attributed to ongoing star formation, rather than secondary ionisation sources, and therefore present a potent test for stellar feedback and stellar population models., Comment: 15 pages, 13 figures, submitted to MNRAS, comments welcome

We present rest-frame optical data of the z~4 sub-millimeter galaxy GN20 obtained with JWST/NIRSpec in integral field spectroscopy (IFS) mode. The H$\alpha$ emission is asymmetric and clumpy and extends over a projected distance of more than 15 kpc. To first order, the large-scale ionised gas kinematics are consistent with a turbulent ($\sigma\sim90$ km/s), rotating disc ($v_{\rm rot}\sim500$ km/s), congruent with previous studies of its molecular and ionised gas kinematics. However, we also find clear evidence for non-circular motions in the H$\alpha$ kinematics. We discuss their possible connection with various scenarios, such as external perturbations, accretion or radial flows. In the centre of GN20, we find broad line emission (FWHM $\sim1000-2000$ km/s) in the H$\alpha$+[N II] complex, suggestive of fast, AGN-driven winds or, alternatively, of the broad-line region of an active black hole. Elevated values of [N II]$\lambda6583$/H$\alpha>0.4$ and EW(H$\alpha)>6$ \r{A}, throughout large parts of GN20 suggest that feedback from the active black hole is able to photo-ionise the interstellar medium. Our data corroborates that GN20 offers a unique opportunity to observe key processes in the evolution of the most massive present-day galaxies acting in concert, over 12 billion years ago., Comment: 12 pages, 8 figures; accepted for publication in MNRAS; doi:10.1093/mnras/stae1993

An increasing number of observations and simulations suggests that low-power (<10$^{44}$ erg s$^{-1}$) jets may be a significant channel of feedback produced by active galactic nuclei (AGN), but little is known about their actual effect on their host galaxies from the observational point of view. We targeted four luminous type 2 AGN hosting moderately powerful radio emission ($\sim$10$^{44}$ erg s$^{-1}$), two of which and possibly a third are associated with jets, with optical integral field spectroscopy observations from the Multi Unit Spectroscopic Explorer (MUSE) at the Very Large Telescope (VLT) to analyze the properties of their ionized gas as well as the properties and effects of ionized outflows. We combined these observations with Very Large Array (VLA) and e-MERLIN data to investigate the relations and interactions between the radio jets and host galaxies. We detected ionized outflows as traced by the fast bulk motion of the gas. The outflows extended over kiloparsec scales in the direction of the jet, when present. In the two sources with resolved radio jets, we detected a strong enhancement in the emission-line velocity dispersion (up to 1000 km s$^{-1}$) perpendicular to the direction of the radio jets. We also found a correlation between the mass and the energetics of this high-velocity dispersion gas and the radio power, which supports the idea that the radio emission may cause the enhanced turbulence. This phenomenon, which is now being observed in an increasing number of objects, might represent an important channel for AGN feedback on galaxies., Comment: 18 pages, 17 figures

Motivated by the recent JWST discovery of galaxy overdensities during the Epoch of Reionzation, we examine the physical properties of high-$z$ protoclusters and their evolution using the FLAMINGO simulation suite. We investigate the impact of the apertures used to define protoclusters, because the heterogeneous apertures used in the literature have limited our understanding of the population. Our results are insensitive to the uncertainties of the subgrid models at a given resolution, whereas further investigation into the dependence on numerical resolution is needed. When considering galaxies more massive than $M_\ast\,{\simeq}\,10^8\,{\rm M_\odot}$, the FLAMINGO simulations predict a dominant contribution from progenitors similar to those of the Coma cluster to the cosmic star-formation rate density during the reionization epoch. Our results indicate the onset of suppression of star formation in the protocluster environments as early as $z\,{\simeq}\,5$. The galaxy number density profiles are similar to NFW at $z\,{\lesssim}\,1$ while showing a steeper slope at earlier times before the formation of the core. Different from most previous simulations, the predicted star-formation history for individual protoclusters is in good agreement with observations. We demonstrate that, depending on the aperture, the integrated physical properties including the total (dark matter and baryonic) mass can be biased by a factor of 2 to 5 at $z\,{=}\,5.5$--$7$, and by an order of magnitude at $z\,{\lesssim}\,4$. This correction suffices to remove the ${\simeq}\,3\,\sigma$ tensions with the number density of structures found in recent JWST observations., Comment: 22 pages, 15 figures, accepted for publication in MNRAS

JWST has recently sparked a new era of Ly$\alpha$ spectroscopy, delivering the first measurements of the Ly$\alpha$ escape fraction and velocity profile in typical galaxies at $z\simeq6-10$. These observations offer new prospects for insight into the earliest stages of reionization. But to realize this potential, we need robust models of Ly$\alpha$ properties in galaxies at $z\simeq5-6$ when the IGM is mostly ionized. Here we use new JWST observations from the JADES and FRESCO surveys combined with VLT/MUSE and Keck/DEIMOS data to characterize statistical distributions of Ly$\alpha$ velocity offsets, escape fractions, and EWs in $z\simeq5-6$ galaxies. We find that galaxies with large Ly$\alpha$ escape fractions (> 0.2) are common at $z\simeq5-6$, comprising 30 per cent of Lyman break selected samples. Comparing to literature studies, our census suggests that Ly$\alpha$ becomes more prevalent in the galaxy population toward higher redshift from $z\sim3$ to $z\sim6$, although we find that this evolution slows considerably between $z\sim5$ and $z\sim6$, consistent with modest attenuation from residual HI in the mostly ionized IGM at $z\simeq5-6$. We find significant evolution in Ly$\alpha$ velocity profiles between $z\simeq2-3$ and $z\simeq5-6$, likely reflecting the influence of resonant scattering from residual intergalactic HI on the escape of Ly$\alpha$ emission near line center. This effect will make it challenging to use Ly$\alpha$ peak offsets as a probe of Lyman continuum leakage at $z\simeq5-6$. We use our $z\simeq5-6$ Ly$\alpha$ distributions to make predictions for typical Ly$\alpha$ properties at $z\gtrsim8$ and discuss implications of a recently-discovered Ly$\alpha$ emitter at $z\simeq8.5$ with a small peak velocity offset (156 km s$^{-1}$)., Comment: 31 pages, 12 figures, accepted by MNRAS

We present HOMERUN (Highly Optimized Multi-cloud Emission-line Ratios Using photo-ionizatioN), a new approach to modelling emission lines from photoionized gas that can simultaneously reproduce all observed line intensities from a wide range of ionization levels and with high accuracy. Our approach is based on the weighted combination of multiple single-cloud photoionization models and, contrary to previous works, the novelty of our approach consists in using the weights as free parameters of the fit and constraining them with the observed data. One of the main applications of HOMERUN is the accurate determination of gas-phase metallicities and we show that a critical point is to allow for a variation of the N/O and S/O abundance ratios which can significantly improve the quality of the fit and the accuracy of the results. Moreover, our approach provides a major improvement compared to the single-cloud, constant-pressure models commonly used in the literature. By using high-quality literature spectra of H ii regions where 10 to 20 emission lines (including several auroral lines) are detected with high signal-to-noise ratio, we show that all lines are reproduced by the model with an accuracy better than 10%. In particular, the model is able to simultaneously reproduce [O i]6300, 6363, [O ii]3726, 3729, [O iii]4959, 5007, [S ii]6717, 6731, and [S iii]9069, 9532 emission lines which, to our knowledge, is an unprecedented result. Finally, we show that the gas metallicities estimated with our models for HII regions in the Milky Way are in agreement with the stellar metallicities than the estimates based on the Te-method. Overall, our method provides a new accurate tool to estimate the metallicity and the physical conditions of the ionized gas. It can be applied to many different science cases from HII regions to AGN and wherever there are emission lines from photoionized gas., Comment: A&A in press, new version following referee report

We present an analysis of the quenching of local observed and simulated galaxies, including an investigation of the dependence of quiescence on both intrinsic and environmental parameters. We apply an advanced machine learning technique utilizing random forest classification to predict when galaxies are star forming or quenched. We perform separate classification analyses for three groups of galaxies: (a) central galaxies; (b) high-mass satellites ($M_{*} > 10^{10.5}{\rm M_{\odot}}$); and (c) low-mass satellites ($M_{*} < 10^{10}{\rm M_{\odot}}$) for three cosmological hydrodynamical simulations (EAGLE, Illustris, and IllustrisTNG), and observational data from the SDSS. The simulation results are unanimous and unambiguous: quiescence in centrals and high-mass satellites is best predicted by intrinsic parameters (specifically central black hole mass), whilst it is best predicted by environmental parameters (specifically halo mass) for low-mass satellites. In observations, we find black hole mass to best predict quiescence for centrals and high mass satellites, exactly as predicted by the simulations. However, local galaxy over-density is found to be most predictive parameter for low-mass satellites. Nonetheless, both simulations and observations do agree that it is environment which quenches low mass satellites. We provide evidence which suggests that the dominance of local over-density in classifying low mass systems may be due to the high uncertainty in halo mass estimation from abundance matching, rather than it being fundamentally a more predictive parameter. Finally, we establish that the qualitative trends with environment predicted in simulations are recoverable in the observation space. This has important implications for future wide-field galaxy surveys., Comment: Accepted to MNRAS; 32 pages; 22 figures

We used low- to high-frequency ALMA observations to investigate the cold gas and dust in ten QSOs at $z\gtrsim 6$. Our analysis of the CO(6-5) and CO(7-6) emission lines in the selected QSOs provided insights into their molecular gas masses, which average around $10^{10}\ \rm M_\odot$, consistent with typical values for high-redshift QSOs. Proprietary and archival ALMA observations in bands 8 and 9 enabled precise constraints on the dust properties and star formation rate (SFR) of four QSOs in our sample for the first time. The examination of the redshift distribution of dust temperatures revealed a general trend of increasing $T_{\rm dust}$ with redshift, which agrees with theoretical expectations. We computed a mean cold dust spectral energy distribution considering all ten QSOs. This offers a comprehensive view of the dust properties of high-$z$ QSOs. The QSOs marked by a more intense growth of the supermassive black hole (HYPERION QSOs) showed lower dust masses and higher gas-to-dust ratios on average, but their $\rm H_2$ gas reservoirs are consistent with those of other QSOs at the same redshift. The observed high SFR in our sample yields high SF efficiencies and thus very short gas depletion timescales ($\tau_{\rm dep}\sim 10^{-2}$ Gyr). Beyond supporting the paradigm that high-$z$ QSOs reside in highly star-forming galaxies, our findings portrayed an interesting evolutionary path at $z>6$. Our study suggests that they are undergoing rapid galaxy growth that might be regulated by strong outflows. Their inferred evolutionary path shows a convergence toward the massive end of the local relation, which supports the idea that they are candidate progenitors of local massive galaxies. The observed pathway involves intense BH growth followed by substantial galaxy growth, in contrast with a symbiotic growth scenario. The abstract has been shortened (full version in the article)., Comment: 29 pages; 6 tables; 18 figures. Accepted by A&A. A section about SF efficiency has been added compared to the previous version

We present the UV-to-NIR size evolution of a sample of 161 quiescent galaxies (QGs) with $M_*>10^{10}M_\odot$ over $0.510^{10.6}M_\odot$. To constrain the physical mechanisms driving the apparent size evolution, we study the relationship between $R_e$ and the formation redshift ($z_{form}$) of QGs. For lower-mass QGs, this relationship is broadly consistent with $R_e\sim(1+z_{form})^{-1}$, in line with the expectation of the progenitor effect. For higher-mass QGs, the relationship between $R_e$ and $z_{form}$ depends on stellar age. Older QGs have a steeper relationship between $R_e$ and $z_{form}$ than that expected from the progenitor effect alone, suggesting that mergers and/or post-quenching continuous gas accretion drive additional size growth in very massive systems. We find that the $z>3$ QGs in our sample are very compact, with mass surface densities $\Sigma_e\gtrsim10^{10} M_\odot/\rm{kpc}^2$, and their $R_e$ are possibly even smaller than anticipated from the size evolution measured for lower-redshift QGs. Finally, we take a close look at the structure of GS-9209, one of the earliest confirmed massive QGs at $z_{spec}\sim4.7$. From UV to NIR, GS-9209 becomes increasingly compact, and its light profile becomes more spheroidal, showing that the color gradient is already present in this earliest massive QG., Comment: 28 pages, 19 figures, submitted to ApJ

We present the robust selection of quiescent (QG) and post-starburst (PSB) galaxies using ultra-deep NIRCam and MIRI imaging from the JWST Advanced Deep Extragalactic Survey (JADES). Key to this is MIRI 7.7$\mu$m imaging which breaks the degeneracy between old stellar populations and dust attenuation at $33$., Comment: 27 pages, 10 figures, 2 tables (not including appendices or references). Submitted to ApJ. Comments welcome!

We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters spanning $0.4-0.9\mu\mathrm{m}$) and novel JWST images with 14 filters spanning $0.8-5\mu\mathrm{m}$, including 7 medium-band filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data at $>2.3\mu\mathrm{m}$ to construct an ultradeep image, reaching as deep as $\approx31.4$ AB mag in the stack and 30.3-31.0 AB mag ($5\sigma$, $r=0.1"$ circular aperture) in individual filters. We measure photometric redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts $z=11.5-15$. These objects show compact half-light radii of $R_{1/2}\sim50-200$pc, stellar masses of $M_{\star}\sim10^7-10^8 M_{\odot}$, and star-formation rates of $\mathrm{SFR}\sim0.1-1\,M_{\odot}\,\mathrm{yr}^{-1}$. Our search finds no candidates at $15

A surprising finding of recent studies is the large number of Active Galactic Nuclei (AGN) associated with moderately massive black holes ($\rm \log(M_\bullet/M_\odot)\sim 6-8$), in the first billion years after the Big Bang ($z>5$). In this context, a relevant finding has been the large fraction of candidate dual AGN, both at large separations (several kpc) and in close pairs (less than a kpc), likely in the process of merging. Frequent black hole merging may be a route for black hole growth in the early Universe; however, previous findings are still tentative and indirect. We present JWST/NIRSpec-IFU observations of a galaxy at $z=7.15$ in which we find evidence for a $\rm \log(M_\bullet/M_\odot)\sim7.7$ accreting black hole, as traced by a broad component of H$\beta$ emission, associated with the Broad Line Region (BLR) around the black hole. This BLR is offset by 620 pc in projection from the centroid of strong rest-frame optical emission, with a velocity offset of $\sim$40 km/s. The latter region is also characterized by (narrow) nebular emission features typical of AGN, hence also likely hosting another accreting black hole, although obscured (type 2, narrow-line AGN). We exclude that the offset BLR is associated with Supernovae or massive stars, and we interpret these results as two black holes in the process of merging. This finding may be relevant for estimates of the rate and properties of gravitational wave signals from the early Universe that will be detected by future observatories like LISA., Comment: 12 pages, 5 figures; accepted for publication in MNRAS; doi:10.1093/mnras/stae943

The SPT0311-58 system resides in a massive dark matter halo at z ~ 6.9. It hosts two dusty galaxies (E and W) with a combined star formation rate of ~3500 Msun/yr. Its surrounding field exhibits an overdensity of sub-mm sources, making it a candidate proto-cluster. We use spatially-resolved spectroscopy provided by the JWST/NIRSpec Integral Field Unit (IFU) to probe a field of view (FoV) ~ 17 x 17 kpc^2 around this object. These observations have revealed ten new galaxies at z ~ 6.9, characterised by dynamical masses spanning from ~10^9 to 10^10 Msun and a range in radial velocities of ~ 1500 km/s, in addition to the already known E and W galaxies. The implied large number density, and the wide spread in velocities, indicate that SPT0311-58 is at the core of a proto-cluster, immersed in a very massive dark matter halo of ~ 5 x 10^12 Msun. Hence, it represents the most massive proto-cluster ever found at the EoR. We also study the dynamical stage of the system and find that it likely is not fully virialised. The galaxies exhibit a great diversity of properties showing a range of evolutionary stages. We derive their ongoing Ha-based unobscured SFR, and find that its contribution to the total SF varies significantly across the galaxies in the system. Their ionization conditions range from those typical of field galaxies at similar redshift recently studied with JWST to those found in more evolved objects at lower z. The metallicity spans more than 0.8 dex across the FoV, reaching nearly solar values in some cases. The detailed IFU spectroscopy of the E galaxy reveals that it is actively assembling its stellar mass, showing sub-kpc inhomogeneities, and a metallicity gradient that can be explained by accretion of low metallicity gas from the IGM. The kinematic maps indicate departures from regular rotation, high turbulence, and a possible pre-collision minor merger. (Abridged), Comment: Revised version: minor changes, improved figures, updated references

We present the identification of 42 narrow-line active galactic nuclei (type-2 AGN) candidates in the two deepest observations of the JADES spectroscopic survey with JWST/NIRSpec. The spectral coverage and the depth of our observations allow us to select narrow-line AGNs based on both rest-frame optical and UV emission lines up to z=10. Due to the metallicity decrease of galaxies, at $z>3$ the standard optical diagnostic diagrams (N2-BPT or S2-VO87) become unable to distinguish many AGN from other sources of photoionisation. Therefore, we also use high ionisation lines, such as HeII$\lambda$4686, HeII$\lambda$1640, NeIV$\lambda$2422, NeV$\lambda$3420, and NV$\lambda$1240, also in combination with other UV transitions, to trace the presence of AGN. Out of a parent sample of 209 galaxies, we identify 42 type-2 AGN (although 10 of them are tentative), giving a fraction of galaxies in JADES hosting type-2 AGN of about $20\pm3$\%, which does not evolve significantly in the redshift range between 2 and 10. The selected type-2 AGN have estimated bolometric luminosities of $10^{41.3-44.9}$ erg s$^{-1}$ and host-galaxy stellar masses of $10^{7.2-9.3}$ M$_{\odot}$. The star formation rates of the selected AGN host galaxies are consistent with those of the star-forming main sequence. The AGN host galaxies at z=4-6 contribute $\sim$8-30 \% to the UV luminosity function, slightly increasing with UV luminosity., Comment: 23 pages 13 figures

State-of-the-art 19th century spectroscopy led to the discovery of quantum mechanics, and 20th century spectroscopy led to the confirmation of quantum electrodynamics. State-of-the-art 21st century astrophysical spectrographs, especially ANDES at ESO's ELT, have another opportunity to play a key role in the search for, and characterization of, the new physics which is known to be out there, waiting to be discovered. We rely on detailed simulations and forecast techniques to discuss four important examples of this point: big bang nucleosynthesis, the evolution of the cosmic microwave background temperature, tests of the universality of physical laws, and a real-time model-independent mapping of the expansion history of the universe (also known as the redshift drift). The last two are among the flagship science drivers for the ELT. We also highlight what is required for the ESO community to be able to play a meaningful role in 2030s fundamental cosmology and show that, even if ANDES only provides null results, such `minimum guaranteed science' will be in the form of constraints on key cosmological paradigms: these are independent from, and can be competitive with, those obtained from traditional cosmological probes., Comment: 31 pages, 6 figures; submitted to Experimental Astronomy on behalf of the ANDES Science Team; v2: matches accepted version

Finding the emergence of the first generation of metals in the early Universe, and identifying their origin, are some of the most important goals of modern astrophysics. We present deep JWST/NIRSpec spectroscopy of GS-z12, a galaxy at z=12.5, in which we report the detection of C III]${\lambda}{\lambda}$1907,1909 nebular emission. This is the most distant detection of a metal transition and the most distant redshift determination via emission lines. In addition, we report tentative detections of [O II]${\lambda}{\lambda}$3726,3729 and [Ne III]${\lambda}$3869, and possibly O III]${\lambda}{\lambda}$1661,1666. By using the accurate redshift from C III], we can model the Ly${\alpha}$ drop to reliably measure an absorbing column density of hydrogen of $N_{HI} \approx 10^{22}$ cm$^{-2}$ - too high for an IGM origin and implying abundant ISM in GS-z12 or CGM around it. We infer a lower limit for the neutral gas mass of about $10^7$ MSun which, compared with a stellar mass of $\approx4 \times 10^7$ MSun inferred from the continuum fitting, implies a gas fraction higher than about 0.1-0.5. We derive a solar or even super-solar carbon-to-oxygen ratio, tentatively [C/O]>0.15. This is higher than the C/O measured in galaxies discovered by JWST at z=6-9, and higher than the C/O arising from Type-II supernovae enrichment, while AGB stars cannot contribute to carbon enrichment at these early epochs and low metallicities. Such a high C/O in a galaxy observed 350 Myr after the Big Bang may be explained by the yields of extremely metal poor stars, and may even be the heritage of the first generation of supernovae from Population III progenitors., Comment: 13 pages, 8 figures. Submitted to Astronomy & Astrophysics

Using deep JWST imaging from JADES, JEMS and SMILES, we characterize optically-faint and extremely red galaxies at $z>3$ that were previously missing from galaxy census estimates. The data indicate the existence of abundant, dusty and post-starburst-like galaxies down to $10^8$M$_\odot$, below the sensitivity limit of Spitzer and ALMA. Modeling the NIRCam and HST photometry of these red sources can result in extreme, high values for both stellar mass and star formation rate (SFR); however, including 7 MIRI filters out to 21$\mu$m results in decreased mass (median 0.6 dex for log$_{10}$M$^*$/M$_{\odot}>$10), and SFR (median 10$\times$ for SFR$>$100 M$_{\odot}$/yr). At $z>6$, our sample includes a high fraction of little red dots (LRDs; NIRCam-selected dust-reddened AGN candidates). We significantly measure older stellar populations in the LRDs out to rest-frame 3$\mu$m (the stellar bump) and rule out a dominant contribution from hot dust emission, a signature of AGN contamination to stellar population measurements. This allows us to measure their contribution to the cosmic census at $z>3$, below the typical detection limits of ALMA ($L_{\rm IR}<10^{12}L_\odot$). We find that these sources, which are overwhelmingly missed by HST and ALMA, could effectively double the obscured fraction of the star formation rate density at $4

We conduct a systematic search for high-redshift galaxy overdensities at $4.9 < z_{\,\mathrm{spec}} < 8.9$ in both the GOODS-N and GOODS-S fields using JWST/NIRCam imaging from JADES and JEMS in addition to JWST/NIRCam wide field slitless spectroscopy from FRESCO. High-redshift galaxy candidates are identified using HST+JWST photometry spanning $\lambda = 0.4-5.0\ \mu\mathrm{m}$. We confirmed the redshifts for roughly a third of these galaxies using JWST/FRESCO spectroscopy over $\lambda = 3.9-5.0\ \mu\mathrm{m}$ through identification of either $\mathrm{H} \alpha$ or $\left[\mathrm{OIII}\right]\lambda5008$ around the best-fit photometric redshift. The rest-UV magnitudes and continuum slopes of these galaxies were inferred from the photometry: the brightest and reddest objects appear in more dense environments and thus are surrounded by more galaxy neighbors than their fainter and bluer counterparts, suggesting accelerated galaxy evolution within overdense environments. We find $17$ significant ($\delta_{\mathrm{gal}} \geq 3.04$, $N_{\mathrm{galaxies}} \geq 4$) galaxy overdensities across both fields ($7$ in GOODS-N and $10$ in GOODS-S), including the two highest redshift spectroscopically confirmed galaxy overdensities to date at $\left< z_{\mathrm{\,spec}} \right> = 7.954$ and $\left< z_{\mathrm{\,spec}} \right> = 8.222$ (representing densities around $\sim 6$ and $\sim 12$ times that of a random volume). We estimate the total halo mass of these large-scale structures to be $11.5 \leq \mathrm{log}_{10}\left(M_{\mathrm{halo}}/M_{\odot}\right) \leq 13.4$ using an empirical stellar mass to halo mass relation, which are likely underestimates as a result of incompleteness. These protocluster candidates are expected to evolve into massive galaxy clusters with $\mathrm{log}_{10}\left(M_{\mathrm{halo}}/M_{\odot}\right) \gtrsim 14$ by $z = 0$., Comment: Resubmitted to ApJ based on reviewer report; main text has 19 pages, 7 figures (including one figure set), and 2 tables. arXiv admin note: text overlap with arXiv:2302.10217

We present an analysis of the quenching of star formation in massive galaxies ($M_* > 10^{9.5} M_\odot$) within the first 0.5 - 3 Gyr of the Universe's history utilizing JWST-CEERS data. We utilize a combination of advanced statistical methods to accurately constrain the intrinsic dependence of quenching in a multi-dimensional and inter-correlated parameter space. Specifically, we apply Random Forest (RF) classification, area statistics, and a partial correlation analysis to the JWST-CEERS data. First, we identify the key testable predictions from two state-of-the-art cosmological simulations (IllustrisTNG & EAGLE). Both simulations predict that quenching should be regulated by supermassive black hole mass in the early Universe. Furthermore, both simulations identify the stellar potential ($\phi_*$) as the optimal proxy for black hole mass in photometric data. In photometric observations, where we have no direct constraints on black hole masses, we find that the stellar potential is the most predictive parameter of massive galaxy quenching at all epochs from $z = 0 - 8$, exactly as predicted by simulations for this sample. The stellar potential outperforms stellar mass, galaxy size, galaxy density, and S\'ersic index as a predictor of quiescence at all epochs probed in JWST-CEERS. Collectively, these results strongly imply a stable quenching mechanism operating throughout cosmic history, which is closely connected to the central gravitational potential in galaxies. This connection is explained in cosmological models via massive black holes forming and growing in deep potential wells, and subsequently quenching galaxies through a mix of ejective and preventative active galactic nucleus (AGN) feedback., Comment: Accepted to ApJ. 32 pages; 10 figures