The James Webb Space Telescope ( ) opened a new observational window on the primordial Universe. Here we present new JWST NIRSpec integral field spectroscopy (IFS) observations of the z=7.54 quasar ULAS J1342+0928 obtained as part of the Galaxy Assembly with NIRSpec IFS (GA-NIFS) GTO programme. The new data-set obtained with both the prism (R , with a mean (median) value of 480 (390) ̊m M_⊙ , JWST and the high-resolution grating (R emission on ∼7 kpc scales, well above the typical galaxy size at this redshift, likely associated with a past outflow event. Additionally, the high-resolution observations show a more energetic ionised outflow on nuclear scales (łesssim 0.8 kpc). The total ionised mass outflow rate ranges between ∼100 and 2200 ̊m M_⊙ , yr^ allow for a complete description of the quasar emission from the rest-frame UV to optical bands. The low-resolution data reveal the presence of O iii -1 -1 , where the significant spread is mostly due to the lack of tight constraints on the electron density and outflow geometry. This range broadly encompasses the star formation rate range (85--545 ̊m M_⊙ , yr^ -1 ), yet this only represents a lower limit to the total mass outflow rate. By employing an accretion disc modelling, for the first time on data, we manage to robustly estimate the black hole mass and the bolometric luminosity, ̊m łog(M_ JWST BH /(M_⊙))=9.1± 0.2 and ̊m łog(L_ bol /(erg , s^ -1 ))=46.8± 0.1, respectively. We derive an Eddington ratio of ̊m λ_ Edd ∼ 0.4, challenging the paradigm of widespread super-Eddington accretion in quasars at the epoch of re-ionisation. Lastly, we measure the most distant broad line ratios ( / and / ) so far. Interpreting these ratios as proxies to the broad line region metallicity, we find evidence for an early metal enrichment in quasars within 700 Myrs from the Big Bang. Fe ii UV Mg ii Fe ii opt H β

mediawiki-texvcGalaxy assembly was already well underway in the first 400 Myr of cosmic time, as recently revealed by JWST. However, the contribution of these early galaxies to cosmic reionisation remains uncertain. Here we present new JWST/NIRSpec observations of GS-z13-1-LA obtained as part of the OASIS and JADES programmes, whose combined deep (56 h) NIRSpec/PRISM spectrum confirms the Lyman- line detection and blue UV continuum at redshift z = 13.1 presented in a previous work. The measured Lyman- emission (rest-frame equivalent width of 66_-9^+10 Å) and steep continuum slope (β_UV≈ -3) point towards GS-z13-1-LA hosting a remarkably hot and powerful ionising source, and allow at most a modest contribution from the nebular continuum. The steep turnover of the continuum is still present, but less pronounced in the new OASIS spectrum. Combined, this implies that ionising photons may escape GS-z13-1-LA at a sufficient rate to weaken the other, still undetected UV lines, and to lead the formation of a small ionised bubble (R_ion≈ 0.2 pMpc). A yet larger bubble could alleviate the required ionising production efficiency of GS-z13-1-LA from ξ_ion≈ 10^26.4 Hz erg^-1 down to ≈ 10^25.9 Hz erg^-1, still extremely high but more readily reconcilable with stellar models. In turn, this would require a notable overdensity of galaxies with highly efficient ionising capabilities, a scenario for which tentative evidence is found in the form of 16 nearby photometric candidates and one spectroscopically confirmed source, JADES-GS-z13-0. The new OASIS observations therefore confirm the overall picture of GS-z13-1-LA as an early beacon of reionisation, providing compelling evidence for its start only 330 Myr after the Big Bang.

We present an overview of the James Webb Space Telescope (JWST) Advanced Deep Extragalactic Survey (JADES), an ambitious program of infrared imaging and spectroscopy in the GOODS-S and GOODS-N deep fields, designed to study galaxy evolution from high redshift to cosmic noon. JADES uses about 770 hours of Cycle 1 guaranteed time largely from the Near-Infrared Camera (NIRCam) and Near-Infrared Spectrograph (NIRSpec) instrument teams. In GOODS-S, in and around the Hubble Ultra Deep Field and Chandra Deep Field South, JADES produces a deep imaging region of ~45 arcmin$^2$ with an average of 130 hrs of exposure time spread over 9 NIRCam filters. This is extended at medium depth in GOODS-S and GOODS-N with NIRCam imaging of ~175 arcmin$^2$ with an average exposure time of 20 hrs spread over 8-10 filters. In both fields, we conduct extensive NIRSpec multi-object spectroscopy, including 2 deep pointings of 55 hrs exposure time, 14 medium pointings of ~12 hrs, and 15 shallower pointings of ~4 hrs, targeting over 5000 HST and JWST-detected faint sources with 5 low, medium, and high-resolution dispersers covering 0.6-5.3 microns. Finally, JADES extends redward via coordinated parallels with the JWST Mid-Infrared Instrument (MIRI), featuring ~9 arcmin$^2$ with 43 hours of exposure at 7.7 microns and twice that area with 2-6.5 hours of exposure at 12.8 microns For nearly 30 years, the GOODS-S and GOODS-N fields have been developed as the premier deep fields on the sky; JADES is now providing a compelling start on the JWST legacy in these fields.

JWST has discovered an early period of galaxy formation that was more vigorous than expected, which has challenged our understanding of the early Universe. In this work, we present the longest spectroscopic integration ever acquired by JWST/MIRI (t(obs) approximate to 51 hr). This spectrum covers the brightest rest-frame optical nebular emission lines for the luminous galaxy JADES-GS-z14-0 at z = 14.18. Most notably, we detect [O III]lambda lambda 4959, 5007 at approximate to 14 sigma and H alpha at approximate to 4 sigma with these ultradeep observations. These lines reveal that JADES-GS-z14-0 has low dust attenuation with a recent star formation rate of SFR approximate to 8 +/- 2M(circle dot) yr(-1), star formation rate surface density of Sigma(SFR) approximate to 20 +/- 5M(circle dot) yr(-1) kpc(-2), and ionizing photon production efficiency of xi(ion) approximate to 10(25.3 +/- 0.1) Hz erg(-1). Using standard strong-line diagnostics, we infer a gas-phase oxygen abundance of log(10)(O/H)+12 approximate to 7.5 +/- 0.2 (approximate to 6%Z(circle dot)), carbon-to-oxygen ratio of [C/O] approximate to -0.4 +/- 0.2, ionization parameter of log(10)(U)greater than or similar to-2.4 , and density of nH approximate to 690 +/- 200 cm(-3). Using detailed photoionization modeling, we instead derive log(10)(O/H)+12 approximate to 8.5(-0.4)(+0.4) (approximate to 60%Z(circle dot)), log(10)(U)approximate to-1.4(-0.4)(+0.3) , and n(H)approximate to 540(-320)(+520)cm(-3) . The inferred properties of JADES-GS-z14-0 are similar to those measured for similarly luminous galaxies at z > 10 with previous MIRI/Spectroscopy, such as GHZ2/GLASSz12, GN-z11, and MACS0647-JD1. These results suggest extreme ionization conditions and rapid metal enrichment less than 300 Myr after the Big Bang. Existing simulations are unable to reproduce the empirical and inferred properties of JADES-GS-z14-0. This work demonstrates an important step toward understanding the formation of the first stars and heavy elements in the Universe. Future work will focus on the detection of the rest-frame optical continuum and its interpretation for the stellar population properties of JADES-GS-z14-0.

JWST has revealed an overabundance of very bright, blue galaxies at z>10, raising fundamental questions about how star formation and feedback operate at Cosmic Dawn. We present new JWST/NIRSpec MSA PRISM/CLEAR spectroscopy of JADES-GS-z14-0 (z=14.18) obtained with the JADES and OASIS programmes. While the rest-frame UV continuum flux level and shape are consistent between the two datasets, the OASIS spectrum shows a 10σ detection of the CIII]λλ1907,1909 emission line, with a luminosity three times higher than that measured in the JADES data. This difference is naturally explained by the offset in shutter placement between OASIS and JADES, implying that the CIII] emission is spatially displaced by ∼400 pc from the stellar continuum. The non-detection of CIII] in NIRCam medium-band imaging indicates that the emitting region is extended on scales ≳165 pc, with a surface brightness below the detection threshold. Interpreting this diffuse, carbon-enriched gas as the result of ongoing or past outflows, we infer a mass outflow rate of Ṁ_ out∼160 M_⊙ yr^-1. We compare it with the star-formation rate (SFR) and derive a mass-loading factor of η= Ṁ_ out/ SFR = 4-15, suggesting highly efficient feedback at very early times. Finally, we show that, if outflows are one of the mechanisms regulating star formation in JADES-GS-z14-0, the instantaneous star-formation efficiency in massive haloes is constrained to ε_⋆≲0.08. These results support a scenario in which outflows play a crucial role during the earliest phases of galaxy formation. Comparing our results with the current theoretical galaxy formation model, we conclude that a combination of moderate star-formation efficiency and reduced dust attenuation can account for the emergence of luminous galaxies at the highest redshifts.

We present a sample of 2081 sources selected at a photometric redshift z(phot)> 8 across the JADES DR5 data release in GOODS-S and GOODS-N over a total area of 469 arcmin(2). These sources range from MUV = -22 to M-UV = -16, with 19 objects at z(phot )> 14. We estimate the UV slopes for the full sample from fits to the photometry and find evidence for a steepening of the relationship between the UV continuum slope and MUV to higher redshifts, a result that differs from prior analyses of brighter samples in the literature. We provide evidence that over one-quarter of our sources have evidence for being morphologically extended, with many galaxies showing multiple bright knots or clumps even out to z similar to 13-14, an indication of how galaxies at cosmic dawn are growing and evolving. We discuss JADES-GN+189.15982+62.28899, a GOODS-N F200W dropout galaxy at z(phot)similar to 15-18, which has been observed spectroscopically with JWST/NIRSpec in prism mode, resulting in a very low signal-to-noise spectrum that is consistent with the photometry and rules out a number of low-redshift solutions for the source. Finally, we use a subsample of 123 objects in our sample with spectroscopic redshifts to explore the usage of alternate fitting templates and a prescription for Ly alpha damping wing absorption, finding that both produce significant improvements to the estimated photometric redshifts.

This paper accompanies Data Release 4 of the James Webb Space Telescope (JWST) Advanced Deep Extragalactic Survey, which presents the full NIRSpec spectroscopy of the survey. We provide spectra of 5190 targets across Great Observatories Origins Deep Survey (GOODS)-North and GOODS-South (including the Hubble Ultra Deep Field), observed with the low-dispersion ( R approximate to 30-300) prism and three medium-resolution ( R approximate to 1000 ) gratings spanning 0 . 8 < lambda < 5 . 5 & micro;m; 2654 were also observed with the higher resolution ( R approximate to 2700 ) G395H grating. The tiered survey design obtained less than or similar to 20 h exposures for ' 700 galaxies in the Deep and Ultra Deep tiers, and shallower observations ( ' 1-3 h per setting) of > 4400 galaxies in the Medium tiers. Targets were selected from photometric redshifts or colours, with priority given to rest-UV-selected galaxies at z > 5 . 7 and F444W-selected galaxies at 1 . 5 < z < 5 . 7 . We describe the full target selection and present spectroscopic redshifts and success rates. In total, we obtain robust redshifts for 3297 galaxies, including 396 at z > 5 . 7 and 2545 at 1 . 5 < z < 5 . 7 . To facilitate uniform analyses, we define 'gold' subsamples based on UV-and F444W-selection. Using the parent samples and redshift success rates, we construct rest-UV luminosity functions at 6 less than or similar to z less than or similar to 9 from the Medium-and Deep-JWST tiers. Our number densities agree well with previous determinations from both photometric and spectroscopic samples, with modest interloper fractions confirming the reliability of photometric UV-bright galaxy selections at these redshifts.

JADES-GS-z14-0 is the most distant spectroscopically confirmed galaxy yet, at z >= 14. With a UV magnitude of-20.81, it is one of the most luminous galaxies at cosmic dawn and its half-light radius of 260 pc means that stars dominate the observed UV emission. We report the Atacama Large Millimeter/submillimeter Array (ALMA) detection of [OIII]88 mu m line emission with a significance of 6.67 sigma and at a frequency of 223.524 GHz, corresponding to a redshift of 14.1796 +/- 0.0007, which is consistent with the candidate C III] line detected in the NIRSpec spectrum. At this spectroscopic redshift, the Lyman-alpha break identified with NIRSpec requires a damped Lyman-alpha absorber with a column density of log(NHI/cm(-2)) = 21.96. The total [OIII]88 mu m luminosity (log(L[OIII]/L-circle star) = 8.3 +/- 0.1) is fully consistent with the local L[OIII] - SFR relation and indicating a gas-phase metallicity >0.1 Z(circle star). Using prospector spectral energy distribution (SED) modeling and combining the ALMA data with JWST observations, we find Z = 0.17 Z(circle star) and a nonzero escape fraction of ionizing photons (similar to 11%), which is necessary by the code to reproduce the UV spectrum. We measure an [OIII]5007 angstrom/[OIII]88 mu m line flux ratio between 1 and 20, resulting in an upper limit to the electron density of roughly 700 cm-3 assuming a single-cloud photoionization model. The [OIII]emission line is spectrally resolved, with a FWHM of 102(-22)(+29) km s(-1), resulting in a dynamical mass of log(Mdyn/M-circle star) = 9.0 +/- 0.2. When compared to the stellar mass, this value represents a conservative upper limit on the gas mass fraction, which ranges from 50% to 80%, depending on the assumed star formation history. Past radiation-driven outflows may have cleared the galaxy from the gas, reducing the gas fraction and thus increasing the escape fraction of ionizing photons.

The James Webb Space Telescope (JWST) opened a new observational window on the primordial Universe. Here we present new JWST NIRSpec integral field spectroscopy (IFS) observations of the z=7.54 quasar ULAS J1342+0928 obtained as part of the Galaxy Assembly with NIRSpec IFS (GA-NIFS) GTO programme. The new data-set obtained with both the prism (R∼100) and the high-resolution grating (R∼2700) allow for a complete description of the quasar emission from the rest-frame UV to optical bands. The low-resolution data reveal the presence of [Oiii] emission on ∼7 kpc scales, well above the typical galaxy size at this redshift, likely associated with a past outflow event. Additionally, the high-resolution observations show a more energetic ionised outflow on nuclear scales (≲ 0.6 kpc). The total ionised mass outflow rate ranges between 50 and 300 M_⊙ yr^-1 where the significant spread is mostly due to the lack of tight constraints on the electron density. This range overlaps in part with the star formation rate range (85–545 M_⊙ yr^-1), implying that the nuclear outflow could ultimately lead to an early star formation quenching. By employing an accretion disc modelling, for the first time on JWST data, we manage to robustly estimate the black hole mass and the bolometric luminosity, log(M_BH/(M_⊙))=9.2± 0.2 and log(L_bol/(erg s^-1))=46.8± 0.1, respectively. We derive an Eddington ratio of λ_Edd∼ 0.4, challenging the paradigm of widespread super-Eddington accretion in quasars at the epoch of reionisation.

We analysed ultra-deep JWST observations of the galaxy JADES-GS-z9-0 at z = 9.4327, and derived detailed stellar and interstellar medium (ISM) properties of this luminous (M-UV=-20.43) high-redshift system. Complementary information from NIRCam imaging and NIRSpec spectroscopy (both low and medium resolution) reveal a compact system (R-e similar to 110 pc) characterised by a steeply rising star formation history, which is reflected in the inferred young stellar age (t similar to 3 Myr, light-weighted), high star formation rate surface density (Sigma(SFR)similar to 72 M-circle dot yr(-1) kpc(-2)), high ionisation parameter (log(U) similar to-1.5), low metallicity (12 + log(O/H) similar to 7.5), and low carbon-to-oxygen abundance ([C/O] =-0.64). Leveraging the detection of N III] lambda 1750 we derived a nitrogen-to-oxygen abundance ([N/O] similar to 0) higher than the plateau followed by low-redshift galaxies of similar metallicity, possibly revealing the imprint from (very) massive stars on the ISM enrichment and favouring a top-heavy initial mass function (IMF) scenario. Massive stars powering a hard radiation field are also required to explain the rest-frame UV line ratios, though the presence of the high-excitation [Ne V] lambda 3426 emission line possibly hints at additional ionisation from an active galactic nucleus (AGN). We also report the tentative detection of Ly alpha emission in the G140M spectrum, shifted by similar to 450 km/s redwards of the systemic redshift. Combined with a modelling of the Ly alpha spectral break, we rule out the presence of very high column densities of neutral gas pertaining to local absorbers, as well as any extended surrounding ionised bubbles, suggesting that JADES-GS-z9-0 has not yet significantly contributed to cosmic reionisation.

We present the third data release of the JWST Advanced Deep Extragalactic Survey (JADES), providing both imaging and spectroscopy in the two GOODS fields. Spectroscopy consists of medium-depth and deep NIRSpec/microshutter assembly spectra of 4000 targets, covering the spectral range 0.6–5.3 μ m and observed with both the low-dispersion prism ( R = 30–300) and all three medium-resolution gratings ( R = 500–1500). We describe the observations, data reduction, sample selection, and target allocation. We measured 2375 redshifts (2053 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 2D and 1D fully reduced spectra, with slit-loss corrections and background subtraction optimized for point sources. We also provide redshifts and signal-to-noise ratio > 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.

mediawiki-texvcCosmic Reionisation commenced when ultraviolet (UV) radiation produced in the first galaxies began illuminating the cold, neutral gas that filled the primordial Universe. Recent James Webb Space Telescope (JWST) observations have shown that surprisingly UV-bright galaxies were in place beyond redshift z = 14, when the Universe was less than 300 Myr old. Smooth turnovers of their UV continua have been interpreted as damping-wing absorption of Lyman-α (Lyα), the principal hydrogen transition. However, spectral signatures encoding crucial properties of these sources, such as their emergent radiation field, largely remain elusive. Here we report spectroscopy from the JWST Advanced Deep Extragalactic Survey (JADES) of a galaxy at redshift z = 13.0 that reveal a singular, bright emission line unambiguously identified as Lyα, in addition to a smooth turnover. We observe an equivalent width of EW_Lyα > 40 Å (rest frame), previously only seen at z < 9 where the intervening intergalactic medium (IGM) becomes increasingly ionised. Together with an extremely blue UV continuum, the unexpected Lyα emission indicates the galaxy is a prolific producer and leaker of ionising photons. This suggests massive, hot stars or an active galactic nucleus (AGN) have created an early reionised region to prevent complete extinction of Lyα, thus shedding new light on the nature of the earliest galaxies and the onset of Reionisation only 330 Myr after the Big Bang.

We summarize the properties and initial data release of the JADES Origins Field (JOF), which will soon be the deepest imaging field yet observed with the James Webb Space Telescope (JWST). This field falls within the GOODS-S region about 8' south-west of the Hubble Ultra Deep Field (HUDF), where it was formed initially in Cycle 1 as a parallel field of HUDF spectroscopic observations within the JWST Advanced Deep Extragalactic Survey (JADES). This imaging will be greatly extended in Cycle 2 program 3215, which will observe the JOF for 5 days in six medium-band filters, seeking robust candidates for z>15 galaxies. This program will also include ultra-deep parallel NIRSpec spectroscopy (up to 104 hours on-source, summing over the dispersion modes) on the HUDF. Cycle 3 observations from program 4540 will add 20 hours of NIRCam slitless spectroscopy to the JOF. With these three campaigns, the JOF will be observed for 380 open-shutter hours with NIRCam using 15 imaging filters and 2 grism bandpasses. Further, parts of the JOF have deep 43 hr MIRI observations in F770W. Taken together, the JOF will soon be one of the most compelling deep fields available with JWST and a powerful window into the early Universe. This paper presents the second data release from JADES, featuring the imaging and catalogs from the year 1 JOF observations.

Cosmic reionization began when ultraviolet (UV) radiation produced in the first galaxies began illuminating the cold, neutral gas that filled the primordial Universe1,2. Recent James Webb Space Telescope (JWST) observations have shown that surprisingly UV-bright galaxies were in place beyond redshift z = 14, when the Universe was less than 300 Myr old3-5. Smooth turnovers of their UV continua have been interpreted as damping-wing absorption of Lyman-α (Ly-α), the principal hydrogen transition6-9. However, spectral signatures encoding crucial properties of these sources, such as their emergent radiation field, largely remain elusive. Here we report spectroscopy from the JWST Advanced Deep Extragalactic Survey (JADES10) of a galaxy at redshift z = 13.0 that reveals a singular, bright emission line unambiguously identified as Ly-α, as well as a smooth turnover. We observe an equivalent width of EWLy-α > 40 Å (rest frame), previously only seen at z < 9 where the intervening intergalactic medium becomes increasingly ionized11. Together with an extremely blue UV continuum, the unexpected Ly-α emission indicates that the galaxy is a prolific producer and leaker of ionizing photons. This suggests that massive, hot stars or an active galactic nucleus have created an early reionized region to prevent complete extinction of Ly-α, thus shedding new light on the nature of the earliest galaxies and the onset of reionization only 330 Myr after the Big Bang.

JWST has shed light on galaxy formation and metal enrichment within 300 Myr of the Big Bang. While luminous galaxies at z > 10 often show significant [O III] AA4959, 5007 emission lines, it remains unclear whether such features are prevalent among fainter, more typical galaxies due to observational limits. We present deep imaging and spectroscopy of JADES-GS-z14-1 at z(spec)= 13.86 (-0.05) ( + 0.04), currently the faintest spectroscopically confirmed galaxy at z approximate to 14. It serendipitously received 70.7 hr of MIRI/F770W imaging in the JWST Advanced Deep Extragalactic Survey (JADES), the deepest MIRI exposure for any high-redshift galaxy to date. Nonetheless, we detect only tentative F770W emission of 7.9 +/- 2.8 nJy at 2.8cr significance, constraining the total equivalent width of [O III] lambda lambda 4959, 5007 + H beta to + 520( -380) (+400) & Aring;, weaker than most z> 10 galaxies with MIRI detections. This source is unresolved across 16 NIRCam bands, implying a physical radius less than or similar to 50 pc. NIRSpec/PRISM spectroscopy totaling 56 hr reveals no rest-frame ultraviolet emission lines above 3cr. Stellar population synthesis suggests a stellar mass similar to 4 x 10(7)M(circle dot) and a star formation rate similar to 2 M-circle dot yr(-1). The absence of strong metal emission lines despite intense star formation suggests a gas-phase metallicity below 10% solar and potentially a high escape fraction of ionizing photons. These deep observations provide rare constraints on faint, early galaxies, tracing the onset of chemical enrichment and ionization in the early Universe.

The first observations of the James Webb Space Telescope (JWST) have revolutionized our understanding of the Universe by identifying galaxies at redshift z ≈ 13 (refs. 1-3). 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 models4-8. However, most of these galaxies lack spectroscopic confirmation, so their distances and properties are uncertain. Here we present JWST Advanced Deep Extragalactic Survey-Near-Infrared Spectrograph spectroscopic confirmation of two luminous galaxies at z = 14.32 - 0.20 + 0.08 and z = 13.90 ± 0.17. The spectra reveal ultraviolet continua with prominent Lyman-α 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.

We characterize the earliest galaxy population in the JADES Origins Field, the deepest imaging field observed with JWST. We make use of ancillary Hubble Space Telescope optical images (five filters spanning 0.4-0.9 mu m) and novel JWST images with 14 filters spanning 0.8-5 mu m, including seven medium-band filters, and reaching total exposure times of up to 46 hr per filter. We combine all our data at >2.3 mu m to construct an ultradeep image, reaching as deep as approximate to 31.4 AB mag in the stack and 30.3-31.0 AB mag (5 sigma, r = 01 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 similar to 50-200 pc, stellar masses of M-star similar to 10(7)-10(8) M-circle dot, and star formation rates similar to 0.1-1 M-circle dot yr(-1). Our search finds no candidates at 15 < z < 20, placing upper limits at these redshifts. We develop a forward-modeling approach to infer the properties of the evolving luminosity function without binning in redshift or luminosity that marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the impact of nondetections. We find a z = 12 luminosity function in good agreement with prior results, and that the luminosity function normalization and UV luminosity density decline by a factor of similar to 2.5 from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical models for evolution of the dark matter halo mass function.

We describe new ultra-deep James Webb Space Telescope (JWST) NIRSpec PRISM and grating spectra for the galaxies JADES-GS-z11-0 (z(spec)=11.122(-0.003)(+0.005)) and JADES-GS-z13-0 (z(spec)=13.20(-0.04)(+0.03)), 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 [O II]lambda lambda 3726, 3729 & Aring; and [NE III] lambda 3869 & Aring;, 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-HI/cm(-2))= 22.42(-0.120)(+0.093). 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 '' south of JADES-GS-z11-0 at a similar photometric redshift, hinting at how galaxies grow through interactions in the early Universe.

A statistical analysis of the impact of the diminishing number of operational shutters experienced by the JWST/NIRSpec Micro Shutter Array since Commissioning is presented. It is shown that the number of high priority science targets that NIRSpec is able to observe simultaneously has so far decreased by 3.1 to carry out autonomous MSATA target acquisition, which is more sensitive to the loss of shutters than is the multiplexing. In the flagship case of MSA observations of deep fields, the number of pointings at which it is not possible to reach the required minimum number of 5 Valid Reference Stars has increased from 4.9 the number of higher risk target acquisitions that need to be carried out with fewer than the maximum allowed number of 8 Reference Stars has grown from 27 to 31