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Even though galactic winds are common in galaxies with starbursts or active galactic nuclei (AGN), the role of such gas flows in galaxy evolution remains uncertain. Here we examine how winds vary along a likely evolutionary sequence connecting starburst to post-starburst to quiescent galaxies. To detect the interstellar medium and measure its bulk flows, we examine the residual Na D absorption line doublet after the stellar contribution has been removed from each galaxy’s spectrum. We discover that outflows diminish along this sequence, i.e., as star formation ends. We then focus on the wind behavior within the post-starburst sample, for which we have measured the time elapsed since the starburst ended (post-burst age) via detailed modeling of their star formation histories (French et al.2018). Even within our post-starburst sample, the fraction of galaxies with significant winds and the average wind velocities decrease with post-burst age after controlling for stellar mass.

Several theories have been proposed to describe the formation of black hole seeds in the early Universe and to explain the emergence of very massive black holes observed in the first thousand million years after the Big Bang 1 – 3 . Models consider different seeding and accretion scenarios 4 – 7 , which require the detection and characterization of black holes in the first few hundred million years after the Big Bang to be validated. Here we present an extensive analysis of the JWST-NIRSpec spectrum of GN-z11, an exceptionally luminous galaxy at z  = 10.6, revealing the detection of the [Ne iv ] λ 2423 and CII* λ 1335 transitions (typical of active galactic nuclei), as well as semi-forbidden nebular lines tracing gas densities higher than 10 9  cm −3 , typical of the broad line region of active galactic nuclei. These spectral features indicate that GN-z11 hosts an accreting black hole. The spectrum also reveals a deep and blueshifted CIV λ 1549 absorption trough, tracing an outflow with velocity 800−1,000 km s −1 , probably driven by the active galactic nucleus. Assuming local virial relations, we derive a black hole mass of log ( M BH / M ⊙ ) = 6.2 ± 0.3 , accreting at about five times the Eddington rate. These properties are consistent with both heavy seeds scenarios and scenarios considering intermediate and light seeds experiencing episodic super-Eddington phases. Our finding explains the high luminosity of GN-z11 and can also provide an explanation for its exceptionally high nitrogen abundance. An extensive analysis of the JWST-NIRSpec spectrum of GN-z11 shows a supermassive black hole of a few million solar masses in a galaxy 440 million years after the Big Bang.

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 , 2 – 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 models 4 , 5 , 6 , 7 – 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. JWST–NIRSpec spectroscopic confirmation of two luminous galaxies is presented, proving that luminous galaxies were already in place 300 million years after the Big Bang and are more common than what was expected before JWST.

Finding and characterizing the first galaxies that illuminated the early universe at cosmic dawn is pivotal to understand the physical conditions and the processes that led to the formation of the first stars. In the first few months of operations, imaging from the James Webb Space Telescope (JWST) has been used to identify tens of candidates of galaxies at redshift (z) greater than 10, less than 450 million years after the Big Bang. However, none of such candidates has yet been confirmed spectroscopically, leaving open the possibility that they are actually low-redshift interlopers. Here we present spectroscopic confirmation and analysis of four galaxies unambiguously detected at redshift 10.3 ≤ z ≤ 13.2, previously selected from JWST Near Infrared Camera imaging. The spectra reveal that these primeval galaxies are metal poor, have masses on the order of about 107–108 solar masses and young ages. The damping wings that shape the continuum close to the Lyman edge provide constraints on the neutral hydrogen fraction of the intergalactic medium from normal star-forming galaxies. These findings demonstrate the rapid emergence of the first generations of galaxies at cosmic dawn.As part of the JWST Advanced Deep Extragalactic Survey (JADES), NIRSpec has spectroscopically confirmed four young and metal-poor galaxies at redshift 10.3–13.2, from an early epoch of galaxy formation.

The first observations of thejames 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+0.08-0.20 and z = 13.90 ± 0.17. The spectra reveal ultraviolet continua with prominent Lyman-a 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 beforeJWST. The most distant of the two galaxies is unexpectedly luminous and is spatially resolved with a radius of260 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 present a detailed study of the partial rest-optical (\\(\\lambda_{\\mathrm{obs}} \\approx 3600-5600\\,\\)Å) spectra of \\(N = 328\\) star-forming galaxies at \\(0.6 < z < 1.0\\) from the Large Early Galaxy Astrophysics Census (LEGA-C). We compare this sample with low-redshift (\\(z \\sim 0\\)) galaxies from the Sloan Digital Sky Survey (SDSS), intermediate-redshift (\\(z \\sim 1.6\\)) galaxies from the Fiber Multi-Object Spectrograph (FMOS)-COSMOS Survey, and high-redshift (\\(z \\sim 2\\)) galaxies from the Keck Baryonic Structure Survey (KBSS). At a lookback time of \\(6-8\\ \\mathrm{Gyr}\\), galaxies with stellar masses \\(\\mathrm{log}(\\mathrm{M_{\\ast}/M_{\\odot}}) > 10.25\\) appear remarkably similar to \\(z \\sim 0\\) galaxies in terms of their nebular excitation, as measured using \\(\\mathrm{[O\\,III]}\\lambda5008 / \\mathrm{H}\\beta\\). There is some evidence that \\(0.6 < z < 1.0\\) galaxies with lower \\(\\mathrm{M_{\\ast}}\\) have higher \\(\\mathrm{[O\\,III]}\\lambda5008 / \\mathrm{H}\\beta\\) than \\(z \\sim 0\\) galaxies and are more similar to less evolved \\(z \\sim 1.6\\) and \\(z \\sim 2\\) galaxies, which are offset from the \\(z \\sim 0\\) locus at all \\(\\mathrm{M_{\\ast}}\\). We explore the impact selection effects, contributions from active galactic nuclei, and variations in physical conditions (ionization parameter and gas-phase oxygen abundance) have on the apparent distribution of \\(\\mathrm{[O\\,III]}\\lambda5008 / \\mathrm{H}\\beta\\) and find somewhat higher ionization and lower enrichment in \\(0.6 < z < 1.0\\) galaxies with lower \\(\\mathrm{M_{\\ast}}\\) relative to \\(z \\sim 0\\) galaxies. We use new near-infrared spectroscopic observations of \\(N = 53\\) LEGA-C galaxies to investigate other probes of enrichment and excitation. Our analysis demonstrates the importance of obtaining complete rest-optical spectra of galaxies in order to disentangle these effects.

We measure velocity offsets in the NaI \\(\\lambda\\lambda5890, 5896\\) (Na D) interstellar medium absorption lines to track how neutral galactic winds change as their host galaxies evolve. Our sample of \\(\\sim\\)80,000 SDSS spectra at \\(0.010 < z < 0.325\\) includes starburst, post-starburst, and quiescent galaxies, forming an evolutionary sequence of declining star formation rate (SFR). We detect bulk flows across this sequence, mostly at higher host stellar masses(\\(log(M_{\\star}/M_{\\odot})>10\\)). Along this sequence, the fraction of outflows decreases (\\(76\\pm2\\%\\) to \\(65\\pm4\\%\\) to a 3\\(\\sigma\\) upper limit of \\(34\\%\\)), and the mean velocity offset changes from outflowing to inflowing (\\(-84.6\\pm5.9\\) to \\(-71.6\\pm11.4\\) to \\(76.6\\pm2.3\\,km\\,s^{-1}\\)). Even within the post-starburst sample, wind speed decreases with time elapsed since the starburst ended. These results reveal that outflows diminish as galaxies age. For post-starbursts, there is evidence for an AGN contribution, especially to the speediest outflows: 1) SFR declines faster in time than outflow velocity, a decoupling arguing against massive stellar feedback; 2) of the few outflows strong enough to escape the interstellar medium (9/105), three of the four hosts with measured emission lines are Seyfert galaxies. For disky starburst galaxies, however, the trends suggest flows out of the stellar disk plane (with outflow 1/2-opening angle \\(> 45\\) degree) instead of from the nucleus: the wind velocity decreases as the disk becomes more edge-on, and the outflow fraction, constant at \\(\\sim\\)90\\(\\%\\) for disk inclinations \\(i<45\\) degree, steadily decreases from \\(\\sim\\)90\\(%\\) to 20\\(\\%\\) for \\(i>45\\) degree.

We report optical integral-field spectroscopy in the field of one of the most luminous quasars in the \\(z < 1\\) Universe, PKS0454-22, with the Multi-Unit Spectroscopic Explorer. These data enable the discovery of three large ionized nebulae emitting in [O II], H\\(\\beta\\), and [O III] with projected areas of \\(1720, \\ 1520,\\) and \\(130 \\ \\mathrm{pkpc}^2\\), which we refer to as N1, N2, and N3, respectively. N1 spatially and kinematically surrounds the quasar host and five nearby galaxies. The morphology and kinematics of N1 are most consistent with stripped interstellar medium resulting from ongoing interactions. Its ionization properties can be explained by quasar photoionization. N2 spatially and kinematically surrounds two galaxies which are at projected distances of \\(d \\approx 90 \\ \\mathrm{pkpc}\\) and line-of-sight velocities of \\(\\Delta v \\approx +1410\\ \\mathrm{km\\ s^{-1}}\\) from the quasar. The morphology and kinematics of N2 are also consistent with stripped interstellar medium. However, its ionization state requires additional ionization sources beyond the quasar, likely from fast shocks as it moves through the hot halo associated with a galaxy over-density around the quasar. N3 is not coincident with any galaxies with secure redshifts, and may arise from a cool gas structure in the intragroup medium or a dwarf galaxy. These large ionized nebulae demonstrate that interactions can produce cool gas structures on halo scales, while also possibly facilitating quasar fueling. The growing availability of wide-area integral field spectroscopic data will continue to reveal the morphologies, kinematics, and conditions of the gas flows, which may fuel galaxy and black hole growth.

We present a spatially resolved study of stellar populations in 6 galaxies with stellar masses \\(M_*\\sim10^{10}M_\\odot\\) at \\(z\\sim3.7\\) using 14-filter JWST/NIRCam imaging from the JADES and JEMS surveys. The 6 galaxies are visually selected to have clumpy substructures with distinct colors over rest-frame \\(3600-4100Å\\), including a red, dominant stellar core that is close to their stellar-light centroids. With 23-filter photometry from HST to JWST, we measure the stellar-population properties of individual structural components via SED fitting using Prospector. We find that the central stellar cores are \\(\\gtrsim2\\) times more massive than the Toomre mass, indicating they may not form via single in-situ fragmentation. The stellar cores have stellar ages of \\(0.4-0.7\\) Gyr that are similar to the timescale of clump inward migration due to dynamical friction, suggesting that they likely instead formed through the coalescence of giant stellar clumps. While they have not yet quenched, the 6 galaxies are below the star-forming main sequence by \\(0.2-0.7\\) dex. Within each galaxy, we find that the specific star formation rate is lower in the central stellar core, and the stellar-mass surface density of the core is already similar to quenched galaxies of the same masses and redshifts. Meanwhile, the stellar ages of the cores are either comparable to or younger than the extended, smooth parts of the galaxies. Our findings are consistent with model predictions of the gas-rich compaction scenario for the buildup of galaxies' central regions at high redshifts. We are likely witnessing the coeval formation of dense central cores, along with the onset of galaxy-wide quenching at \\(z>3\\).