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We present the census of H  |$\beta$|  + [ |${\rm O\, {\small III}}$| ] |$4960,5008\rm{\mathring{\rm\,A}}$| emitters at |$6.8\lt z\lt 9.0$| from the JWST FRESCO survey over 124 arcmin |$^2$| in the GOODS-North and GOODS-South fields. Our unbiased spectroscopic search results in 137 spectroscopically confirmed galaxies at |$6.8\lt z\lt 9.0$| with observed [ |${\rm O\, {\small III}}$| ] fluxes |$f_{\rm { [{\rm O\, {\small III}}]}}\gtrsim 1\times 10^{-18}\ \rm {ergs}\ \rm {s}^{-1} \ \rm {cm}^{-2}$|⁠. The rest-frame optical line ratios of the median stacked spectrum (median |$M_{\rm {UV}}=-19.65^{+0.59}_{-1.05}$|⁠) indicate negligible dust attenuation, low metallicity (⁠|$12+\log (\rm {O/H})= 7.2-7.7$|⁠) and a high ionization parameter |$\log _{10}U \simeq -2.5$|⁠. We find a factor |$\times 1.3$| difference in the number density of |$6.8\lt z\lt 9.0$| galaxies between GOODS-South and GOODS-North, which is caused by a single overdensity at |$7.0\lt z\lt 7.2$| in GOODS-North. The bright end of the UV luminosity function of spectroscopically confirmed [ |${\rm O\, {\small III}}$| ] emitters is in good agreement with HST dropout-selected samples. Discrepancies between the observed [ |${\rm O\, {\small III}}$| ] LF, [ |${\rm O\, {\small III}}$| ]/UV ratio, and [ |${\rm O\, {\small III}}$| ] equivalent widths, and that predicted by theoretical models, suggest burstier star-formation histories and/or more heterogeneous metallicity and ionizing conditions in |$z\gt 7$| galaxies. We report a rapid decline of the [ |${\rm O\, {\small III}}$| ] luminosity density at |$z\gtrsim 6\!-\!7$| which cannot be explained by the evolution of the cosmic star-formation rate density. Finally we find that FRESCO detects in only 2h galaxies likely accounting for |$\sim 10-20{{\ \rm per\ cent}}$| of the ionizing budget at |$z=7\!-\!8$| (assuming an escape fraction of |$10{{\ \rm per\ cent}}$|⁠), raising the prospect of directly detecting a significant fraction of the sources of reionization with JWST. [ABSTRACT FROM AUTHOR]

We report ultra-deep, medium-resolution spectroscopic observations for four quiescent galaxies with log |$_{10}(M_*/\mathrm{M_\odot })\gt 11$| at |$3 \lt z \lt 5$|⁠. These data were obtained with JWST NIRSpec as part of the Early eXtragalactic Continuum and Emission Line Science (EXCELS) survey, which we introduce in this work. The first two galaxies are newly selected from PRIMER UDS imaging, both at |$z=4.62$| and separated by 860 pkpc on the sky, within a larger structure for which we confirm several other members. Both formed at |$z\simeq 8-10$|⁠. These systems could plausibly merge by the present day to produce a local massive elliptical galaxy. The other two ultra-massive quiescent galaxies are previously known at |$z=3.99$| and 3.19, with the latter (ZF-UDS-7329) having been the subject of debate as potentially too old and too massive to be accommodated by the |$\Lambda$| -CDM halo-mass function. Both exhibit high stellar metallicities, and for ZF-UDS-7329 we are able to measure the |$\alpha -$| enhancement, obtaining [Mg/Fe] = |$0.42^{+0.19}_{-0.17}$|⁠. We finally evaluate whether these four galaxies are consistent with the |$\Lambda$| -CDM halo-mass function using an extreme value statistics approach. We find that the |$z=4.62$| objects and the |$z=3.19$| object are unlikely within our area under the assumption of standard stellar fractions (⁠|$f_*\simeq 0.1-0.2$|⁠). However, these objects roughly align with the most massive galaxies expected under the assumption of 100 per cent conversion of baryons to stars (⁠|$f_*$| =1). Our results suggest extreme galaxy formation physics during the first billion years, but no conflict with |$\Lambda$| -CDM cosmology. [ABSTRACT FROM AUTHOR]

We present a new determination of the evolving galaxy ultraviolet (UV) luminosity function (LF) over the redshift range |$8.5< z< 15.5$| using a combination of several major Cycle-1 JWST imaging programmes – Public Release IMaging for Extragalactic Research, JWST Advanced Deep Extragalactic Survey, and Next Generation Deep Extragalactic Exploratory Public Survey. This multifield approach yields a total of |$\simeq 370$| arcmin2 of JWST /NIRCam imaging, reaching (5- |$\sigma$|⁠) depths of |$\simeq 30$| AB mag in the deepest regions. We select a sample of 2548 galaxies with a significant probability of lying at high redshift (⁠|$p(z> 8.5)> 0.05$|⁠) to undertake a statistical calculation of the UV LF. Our new measurements span |$\simeq 4$|  mag in UV luminosity at |$z=9-12.5$|⁠ , placing new constraints on both the shape and evolution of the LF at early times. Our measurements yield a new estimate of the early evolution of cosmic star-formation rate density (⁠|$\rho _{\rm {SFR}}$|⁠) confirming the gradual decline deduced from early JWST studies, at least out to |$z \simeq 12$|⁠. Finally we show that the observed early evolution of the galaxy UV LF (and |$\rho _{\rm {SFR}}$|⁠) can be reproduced in a |${\rm \Lambda }$| cold dark matter Universe, with no change in dust properties or star-formation efficiency required out to |$z \simeq 12$|⁠. Instead, a progressive trend towards younger stellar population ages can reproduce the observations, and the typical ages required at |$z \simeq$| 8, 9, 10, and 11 all converge on |$\simeq 380-330$|  Myr after the big bang, indicative of a rapid emergence of early galaxies at |$z \simeq 12 - 13$|⁠. This is consistent with the first indications of a steeper drop-off in |$\rho _{\rm {SFR}}$| we find beyond |$z \simeq 13$|⁠ , possibly reflecting the rapid evolution of the halo mass function at earlier times. [ABSTRACT FROM AUTHOR]

With the advent of JWST , we can probe the rest-frame optical emission of galaxies at |$z\gt 3$| with high sensitivity and spatial resolution, making it possible to accurately characterize red, optically faint galaxies and thus move towards a more complete census of the galaxy population at high redshifts. To this end, we present a sample of 148 massive, dusty galaxies from the JWST /Cosmic Evolution Early Release Science survey, colour-selected using solely JWST bands. With deep JWST /NIRCam data from 1.15 to 4.44  |$\mu$| m and ancillary HST /ACS and WFC3 data, we determine the physical properties of our sample using spectral energy distribution fitting with bagpipes. We demonstrate that our selection method efficiently identifies massive (⁠|$\mathrm{\langle \log {\it M}_\star /M_\odot \rangle \sim 10}$|⁠) and dusty (⁠|$\mathrm{\langle {\it A}_V\rangle \sim 2.7\ mag}$|⁠) sources, with a majority at |$z\,\gt\, 3$| and predominantly lying on the galaxy main sequence. The main results of this work are the stellar mass functions (SMFs) of red, optically faint galaxies from redshifts between |$3\,\lt\, z\,\lt\, 8$|⁠ : these galaxies make up a significant relative fraction of the pre- JWST total SMF at |$3\,\lt\, z\,\lt\, 4$| and |$4\,\lt\, z\,\lt\, 6$|⁠ , and dominate the high-mass end of the pre- JWST SMF at |$6\,\lt\, z\,\lt \,8$|⁠ , suggesting that our census of the galaxy population needs amendment at these epochs. While larger areas need to be surveyed in the future, our results suggest already that the integrated stellar mass density at |$\mathrm{\log {\it M}_\star /M_\odot \ge 9.25}$| may have been underestimated in pre- JWST studies by up to |$\sim$| 15–20% at |$z\sim 3{\!-\!}6$|⁠ , and up to |$\sim$| 45% at |$z\sim 6{\!-\!}8$|⁠ , indicating the rapid onset of obscured stellar mass assembly in the early Universe. [ABSTRACT FROM AUTHOR]

We present results of dust continuum and [C  ii ] |$\, 158\, {\rm \mu m}$| emission line observations of a remarkably UV luminous (M UV = −21.6) galaxy at z = 10.603: GN-z11. Using the Northern Extended Millimeter Array (NOEMA), observations have been carried out over multiple observing cycles. We achieved a high sensitivity resulting in a |$\lambda _{\rm rest}=160\, {\rm \mu m}$| continuum |$1\, \sigma$| sensitivity of |$13.0\, \rm {\mu Jy \, beam}^{ -1}$| and a [C  ii ] emission line |$1\, \sigma$| sensitivity of |$31\, \rm {mJy\, beam^{ -1}\, km \, s}^{ -1}$| using |$50\, \rm {km \, s}^{ -1}$| binning with a |$\sim 2\, {\rm arcsec}$| synthesized beam. Neither dust continuum nor [C  ii ] |$\, 158\, {\rm \mu m}$| line emission are detected at the expected frequency of ν[C ii ] |$= 163.791\, \rm {GHz}$| and the sky location of GN-z11. The upper limits show that GN-z11 is neither luminous in L IR nor L [C ii ], with a dust mass |$3\, \sigma$| limit of |${\rm log}\, (M_{\rm dust}/{\rm {\rm M}_{\odot }}) \, \lt\, 6.5-6.9$| and with a [C  ii ] based molecular gas mass |$3\, \sigma$| limit of log (M mol, [C ii ] |$/{\rm {\rm M}_{\odot }}) \, \lt \, 9.3$|⁠. Together with radiative transfer calculations, we also investigated the possible cause of the dust poor nature of the GN-z11 showed by the blue colour in the UV continuum of GN-z11 (βUV = −2.4), and found that ≳3 × deeper observations are crucial to study dust production at very high-redshift. Nevertheless, our observations show the crucial role of deep mm/submm observations of very high-redshift galaxies to constrain multiple phases in the interstellar medium. [ABSTRACT FROM AUTHOR]

We present the JWST cycle 1 53.8 h medium program FRESCO, short for 'First Reionization Epoch Spectroscopically Complete Observations'. FRESCO covers 62 arcmin2 in each of the two GOODS/CANDELS fields for a total area of 124 arcmin2 exploiting JWST 's powerful new grism spectroscopic capabilities at near-infrared wavelengths. By obtaining ∼2 h deep NIRCam/grism observations with the F 444 W filter, FRESCO yields unprecedented spectra at R ∼ 1600 covering 3.8–5.0 µm for most galaxies in the NIRCam field of view. This setup enables emission line measurements over most of cosmic history, from strong PAH lines at z ∼ 0.2–0.5, to Pa α and Pa β at z ∼ 1–3, He  i and [S  iii ] at z ∼ 2.5–4.5, H α and [N  ii ] at z ∼ 5–6.5, up to [O  iii ] and H β for z ∼ 7–9 galaxies. FRESCO's grism observations provide total line fluxes for accurately estimating galaxy stellar masses and calibrating slit-loss corrections of NIRSpec/MSA spectra in the same field. Additionally, FRESCO results in a mosaic of F 182 M, F 210 M , and F 444 W imaging in the same fields to a depth of ∼28.2 mag (5σ in 0 |${_{.}^{\prime\prime}}$| 32 diameter apertures). Here, we describe the overall survey design and the key science goals that can be addressed with FRESCO. We also highlight several, early science results, including: spectroscopic redshifts of Lyman break galaxies that were identified almost 20 yr ago, the discovery of broad-line active galactic nuclei at z > 4, and resolved Pa α maps of galaxies at z ∼ 1.4. These results demonstrate the enormous power for serendipitous discovery of NIRCam/grism observations. [ABSTRACT FROM AUTHOR]

Over the last few years, both Atacama Large Millimeter/submillimeter Array (ALMA) and Spitzer observations have revealed a population of likely massive galaxies at z > 3 that was too faint to be detected in Hubble Space Telescope (HST) rest-frame ultraviolet imaging. However, due to the very limited photometry for individual galaxies, the true nature of these so-called HST -dark galaxies has remained elusive. Here, we present the first sample of such galaxies observed with very deep, high-resolution NIRCam imaging from the Early Release Science programme CEERS. 30 HST -dark sources are selected based on their red colours across 1.6–4.4 |$\mu$| m. Their physical properties are derived from 12-band multiwavelength photometry, including ancillary HST imaging. We find that these galaxies are generally heavily dust-obscured (AV ∼ 2 mag), massive (log (M /M⊙) ∼ 10), star-forming sources at z ∼ 2−8 with an observed surface density of ∼0.8 arcmin−2. This suggests that an important fraction of massive galaxies may have been missing from our cosmic census at z > 3 all the way into the Epoch of Reionization. The HST -dark sources lie on the main sequence of galaxies and add an obscured star formation rate density of |$\mathrm{3.2^{+1.8}_{-1.3} \times 10^{-3} \,{\rm M}_{\odot }\,yr^{-1}\,Mpc^{-3}}$| at z ∼ 7, showing likely presence of dust in the Epoch of Reionization. Our analysis shows the unique power of JWST to reveal this previously missing galaxy population and to provide a more complete census of galaxies at z  = 2−8 based on rest-frame optical imaging. [ABSTRACT FROM AUTHOR]

Before the end of the Epoch of Reionization, the Hydrogen in the Universe was predominantly neutral. This leads to a strong attenuation of Ly α lines of z ≳ 6 galaxies in the intergalactic medium. Nevertheless, Ly α has been detected up to very high redshifts (z ∼ 9) for several especially UV luminous galaxies. Here, we test to what extent the galaxy's local environment might impact the Ly α transmission of such sources. We present an analysis of dedicated Hubble Space Telescope (HST) imaging in the CANDELS/EGS field to search for fainter neighbours around three of the most UV luminous and most distant spectroscopically confirmed Ly α emitters: EGS-zs8-1, EGS-zs8-2, and EGSY-z8p7 at z spec = 7.73, 7.48, and 8.68, respectively. We combine the multiwavelength HST imaging with Spitzer data to reliably select z ∼ 7–9 galaxies around the central, UV-luminous sources. In all cases, we find a clear enhancement of neighbouring galaxies compared to the expected number in a blank field (by a factor ∼3–9×). Our analysis thus reveals ubiquitous overdensities around luminous Ly α emitting sources in the heart of the cosmic reionization epoch. We show that our results are in excellent agreement with expectations from the Dragons simulation, confirming the theoretical prediction that the first ionized bubbles preferentially formed in overdense regions. While three UV luminous galaxies already have spectroscopic redshifts, the majority of the remaining fainter, surrounding sources are yet to be confirmed via spectroscopy. JWST follow-up observations of the neighbouring galaxies identified here will thus be needed to confirm their physical association and to map out the ionized regions produced by these sources. [ABSTRACT FROM AUTHOR]

The James Webb Space Telescope will allow to spectroscopically study an unprecedented number of galaxies deep into the reionization era, notably by detecting [O  iii ]λλ4959, 5007, and H β nebular emission lines. To efficiently prepare such observations, we photometrically select a large sample of galaxies at z ∼ 8 and study their rest-frame optical emission lines. Combining data from the GOODS Re-ionization Era wide-Area Treasury from Spitzer (GREATS) survey and from HST we perform spectral energy distribution (SED) fitting, using synthetic SEDs from a large grid of photoionization models. The deep Spitzer /IRAC data combined with our models exploring a large parameter space enables to constrain the [O  iii ] + H β fluxes and equivalent widths for our sample, as well as the average physical properties of z ∼ 8 galaxies, such as the ionizing photon production efficiency with |$\log (\xi _\mathrm{ion}/\mathrm{erg}^{-1}\mathrm{Hz})\ge 25.77$|⁠. We find a relatively tight correlation between the [O  iii ] + H β and UV luminosity, which we use to derive for the first time the [O  iii ]λλ4959, 5007 + H β luminosity function (LF) at z ∼ 8. The z ∼ 8 [O  iii ] + H β LF is higher at all luminosities compared to lower redshift, as opposed to the UV LF, due to an increase of the [O  iii ] + H β luminosity at a given UV luminosity from z ∼ 3 to z ∼ 8. Finally, using the [O  iii ] + H β LF, we make predictions for JWST /NIRSpec number counts of z ∼ 8 galaxies. We find that the current wide-area extragalactic legacy fields are too shallow to use JWST at maximal efficiency for z ∼ 8 spectroscopy even at 1 h depth and JWST pre-imaging to ≳30 mag will be required. [ABSTRACT FROM AUTHOR]

Detections of Lyman-break galaxies (LBGs) at high-redshift are affected by gravitational a lensing induced by foreground deflectors not only in galaxy clusters, but also in blank fields. " We quantify the impact of strong magnification in the samples of B435, V606, i775 and z850 & Y105 O dropouts (4 ≲ z ≲ 8) observed in the eXtreme Deep Field (XDF) and the Cosmic Assembly t Near-infrared Deep Extragalactic Legacy Survey (CANDELS) fields by investigating the / proximity of dropouts to foreground objects. We find that per cent of bright z ~ 7 LBGs (mH160 < 26) have been strongly lensed (μ > 2) by foreground objects. This fraction decreases O from ~3.5 per cent at z ~ 6 to ~1.5 per cent at z ~ 4. Since the observed fraction of strongly O lensed LBGs is a function of the shape of the luminosity function (LF), it can be used to derive o Schechter parameters, α and M*, independently from galaxy number counts. Our magnification g bias analysis yields Schechter-function parameters in close agreement with those determined o from galaxy counts albeit with larger uncertainties. Extrapolation of our analysis to z ≳ 8 suggests that surveys with JWST, WFIRST and Euclid should find excess LBGs at the bright " end, over an intrinsic exponential cutoff. Finally, we highlight how the magnification bias g measurement near the XDF detection limit can be used to probe the population of galaxies o beyond this limit. Preliminary results suggest that the magnification bias at MUV ~ --18 is §* weaker than expected if α ≲ --1.7 extends well below the current detection limits. This could 2 imply a flattening of the LF at MUV ≳ --16.5. However, selection effects and completeness 5 estimates are difficult to quantify precisely. Thus, we do not rule out a steep LF extending to Muv ≳ --15. [ABSTRACT FROM AUTHOR]

ABSTRACT We present the details and early results from a deep near-infrared survey utilizing the NICMOS instrument on the Hubble Space Telescope centred around massive M* > 1011 M ⊙ galaxies at 1.7 < z < 2.9 found within the Great Observatories Origins Deep Survey (GOODS) fields North and South. The GOODS NICMOS Survey (GNS) was designed to obtain deep F160W ( H-band) imaging of 80 of these massive galaxies and other colour-selected objects such as Lyman-break dropouts, BzK objects, distant red galaxies (DRGs), extremely red objects (EROs), Spitzer-selected EROs, BX/BM galaxies, as well as flux-selected submillimetre galaxies. We present in this paper details of the observations, our sample selection, as well as a description of the properties of the massive galaxies found within our survey fields. This includes photometric redshifts, rest-frame colours and stellar masses. We furthermore provide an analysis of the selection methods for finding massive galaxies at high redshifts, including colour-selection methods and how galaxy populations selected through these colour methods overlap. We find that a single colour selection method cannot locate all of the massive galaxies, with no one method finding more than 70 per cent. We however find that the combination of these colour methods finds nearly all of the massive galaxies that would have been identified in a photometric redshift sample, with the exception of apparently rare blue massive galaxies. By investigating the rest-frame ( U− B) versus MB diagram for these galaxies, we furthermore show that there exists a bimodality in colour-magnitude space at z < 2, driven by stellar mass, such that the most massive galaxies are systematically red up to z∼ 2.5, while lower mass galaxies tend to be blue. We also discuss the number densities for galaxies with stellar masses M* > 1011 M ⊙, whereby we find an increase of a factor of 8 between z= 3 and 1.5, demonstrating that this is an epoch when massive galaxies establish most of their stellar mass. We also provide an overview of the evolutionary properties of these galaxies, such as their merger histories, and size evolution. [ABSTRACT FROM AUTHOR]

We present a detailed study of the spatially resolved kinematics, star formation and stellar mass in a highly amplified galaxy at behind the lensing cluster MS 1358+62. We use the observed optical, near- and mid-infrared imaging from Hubble Space Telescope ACS & NICMOS and Spitzer IRAC to derive the stellar mass and the Gemini/NIFS IFU to investigate the velocity structure of the galaxy from the nebular [O ii]λλ3726.8,3728.9 emission. Using a detailed gravitational lens model, we account for lensing amplification factor 12.5 ± 2.0 and find that this intrinsically galaxy has a stellar mass of , a dynamical mass of (within of 2 kpc) and a star formation rate of . The source-plane UV/optical morphology of this galaxy is dominated by five discrete star-forming regions. Exploiting the dynamical information we derive masses for individual star-forming regions of with sizes of ∼200 pc. We find that, at a fixed size, the star formation rate density within these H ii regions is approximately two orders of magnitude greater than those observed in local spiral/starburst galaxies, but consistent with the most massive H ii regions in the local Universe such as 30 Doradus. Finally, we compare the spatially resolved nebular emission-line velocity with the Lyα and UV interstellar medium (ISM) lines and find that this galaxy is surrounded by a galactic scale outflow in which the Lyα appears redshifted by ∼150 km s−1 and the UV-ISM lines blueshifted by from the (systemic) nebular emission. The velocity structure of the outflow mirrors that of the nebular emission suggesting the outflow is young (≲15 Myr), and has yet to burst out of the system. Taken together, these results suggest that this young galaxy is undergoing its first major epoch of mass assembly. [ABSTRACT FROM AUTHOR]