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Abstract Investigating the impact of galaxy properties on emergent Lyαemission is crucial for reionization studies, given the sensitivity of Lyαto neutral hydrogen. This study presents an analysis of the physical characteristics of 155 star-forming galaxies, 29 with Lyαdetected, and 126 with Lyαnot detected with LyαEW < 20 Å, atz= 1.9–3.5, drawn from the MOSFIRE Deep Evolution Field survey, that have overlapping observations from the Hobby–Eberly Telescope Dark Energy Experiment survey. To unravel the interstellar medium (ISM) conditions in our sample, we developed a custom nebular line modeling algorithm based on the MAPPINGS V photoionization model grid and theemceeframework. Combining nebular-based ISM properties with photometry-based global properties, constrained viaBagpipes, we explore distinctions in the stellar and gas properties between Lyα-detected and Lyα-nondetected galaxies. Our analysis reveals statistically significant differences between the two samples in terms of stellar mass and dust attenuation (A_V) at >2σsignificance, as determined via a Kolmogorov–Smirnov test. Moreover, there are weaker (≲1σsignificance) indications that the ionization parameter and metallicity differ between the two samples. Our results demonstrate that the escape fraction of Lyα( $f_{\mathrm{esc}}^{\mathrm{Ly}\alpha }$) is inversely correlated with stellar mass, star formation rate, and dust attenuation, while it is positively correlated with the ionization parameter, with significance levels exceeding 2σ. Our findings suggest that the interstellar environments of Lyα-detected galaxies, characterized by low mass, low dust, low gas-phase metallicity, and high ionization parameters, play a pivotal role in promoting the escape of Lyαradiation. 

Abstract We present the first results from the Web Epoch of Reionization LyαSurvey (WERLS), a spectroscopic survey of Lyαemission using Keck I/MOSFIRE and LRIS. WERLS targets bright (J< 26) galaxy candidates with photometric redshifts of 5.5 ≲z≲ 8 selected from pre-JWST imaging embedded in the Epoch of Reionization (EoR) within three JWST deep fields: CEERS, PRIMER, and COSMOS-Web. Here, we report 11z∼ 7–8 Lyαemitters (LAEs; three secure and eight tentative candidates) detected in the first five nights of WERLS MOSFIRE data. We estimate our observed LAE yield is ∼13%, which is broadly consistent with expectations assuming some loss from redshift uncertainty, contamination from sky OH lines, and that the Universe is approximately half-ionized at this epoch, whereby observable Lyαemission is unlikely for galaxies embedded in a neutral intergalactic medium. Our targets are selected to be UV-bright, and span a range of absolute UV magnitudes with −23.1 <M_UV< −19.8. With two LAEs detected atz= 7.68, we also consider the possibility of an ionized bubble at this redshift. Future synergistic Keck+JWST efforts will provide a powerful tool for pinpointing beacons of reionization and mapping the large-scale distribution of mass relative to the ionization state of the Universe. 

Abstract We investigate the stellar mass–black hole mass ( ${\mathit{}}_{*}–{\mathit{}}_{\mathrm{BH}}$) relation with type 1 active galactic nuclei (AGNs) down to ${\mathit{}}_{\mathrm{BH}}={10}^7{M}_{\odot }$, corresponding to a ≃ −21 absolute magnitude in rest-frame ultraviolet, atz= 2–2.5. Exploiting the deep and large-area spectroscopic survey of the Hobby–Eberly Telescope Dark Energy Experiment (HETDEX), we identify 66 type 1 AGNs with ${\mathit{}}_{\mathrm{BH}}$ranging from 10⁷–10¹⁰M_⊙that are measured with single-epoch virial method using Civemission lines detected in the HETDEX spectra. ${\mathit{}}_{*}$of the host galaxies are estimated from optical to near-infrared photometric data taken with Spitzer, the Wide-field Infrared Survey Explorer, and ground-based 4–8 m class telescopes byCIGALEspectral energy distribution (SED) fitting. We further assess the validity of SED fitting in two cases by host-nuclear decomposition performed through surface brightness profile fitting on spatially resolved host galaxies with the James Webb Space Telescope/NIRCam CEERS data. We obtain the ${\mathit{}}_{*}–{\mathit{}}_{\mathrm{BH}}$relation covering the unexplored low-mass ranges of ${\mathit{}}_{\mathrm{BH}}\sim {10}^7–{10}^8{M}_{\odot }$, and conduct forward modeling to fully account for the selection biases and observational uncertainties. The intrinsic ${\mathit{}}_{*}–{\mathit{}}_{\mathrm{BH}}$relation atz∼ 2 has a moderate positive offset of 0.52 ± 0.14 dex from the local relation, suggestive of more efficient black hole growth at higher redshift even in the low-mass regime of ${\mathit{}}_{\mathrm{BH}}\sim {10}^7–{10}^8{M}_{\odot }$. Our ${\mathit{}}_{*}–{\mathit{}}_{\mathrm{BH}}$relation is inconsistent with the ${\mathit{}}_{\mathrm{BH}}$suppression at the low- ${\mathit{}}_{*}$regime predicted by recent hydrodynamic simulations at a 98% confidence level, suggesting that feedback in the low-mass systems may be weaker than those produced in hydrodynamic simulations. 

Abstract We analyze the evolution of massive (log₁₀[M_⋆/M_⊙] > 10) galaxies atz∼ 1–4 selected from JWST Cosmic Evolution Early Release Survey (CEERS). We infer the physical properties of all galaxies in the CEERS NIRCam imaging through spectral energy distribution (SED) fitting withdense basisto select a sample of high-redshift massive galaxies. Where available we include constraints from additional CEERS observing modes, including 18 sources with MIRI photometric coverage, and 28 sources with spectroscopic confirmations from NIRSpec or NIRCam WFSS. We sample the recovered posteriors in stellar mass from SED fitting to infer the volume densities of massive galaxies across cosmic time, taking into consideration the potential for sample contamination by active galactic nuclei. We find that the evolving abundance of massive galaxies tracks expectations based on a constant baryon conversion efficiency in dark matter halos forz∼ 1–4. At higher redshifts, we observe an excess abundance of massive galaxies relative to this simple model, resulting in a shallower decline of observed volume densities of massive galaxies. These higher abundances can be explained by modest changes to star formation physics and/or the efficiencies with which star formation occurs in massive dark matter halos, and are not in tension with modern cosmology. 

Abstract We present rest-frame optical emission-line flux ratio measurements for fivez> 5 galaxies observed by the James Webb Space Telescope Near-Infared Spectrograph (NIRSpec) in the SMACS 0723 Early Release Observations. We add several quality-control and post-processing steps to the NIRSpec pipeline reduction products in order to ensure reliablerelativeflux calibration of emission lines that are closely separated in wavelength, despite the uncertainabsolutespectrophotometry of the current version of the reductions. Compared toz∼ 3 galaxies in the literature, thez> 5 galaxies have similar [Oiii]λ5008/Hβratios, similar [Oiii]λ4364/Hγratios, and higher (∼0.5 dex) [NeIII]λ3870/[OII]λ3728 ratios. We compare the observations to MAPPINGS V photoionization models and find that the measured [NeIII]λ3870/[OII]λ3728, [Oiii]λ4364/Hγ, and [Oiii]λ5008/Hβemission-line ratios are consistent with an interstellar medium (ISM) that has very high ionization ( $\log \left(Q\right)\simeq 8-9$, units of cm s⁻¹), low metallicity (Z/Z_⊙≲ 0.2), and very high pressure ( $\log \left(P/k\right)\simeq 8-9$, units of cm⁻³). The combination of [Oiii]λ4364/Hγand [Oiii]λ(4960 + 5008)/Hβline ratios indicate very high electron temperatures of $4.1<\log \left(T_e/\mathrm{K}\right)<4.4$, further implying metallicities ofZ/Z_⊙≲ 0.2 with the application of low-redshift calibrations for “T_e-based” metallicities. These observations represent a tantalizing new view of the physical conditions of the ISM in galaxies at cosmic dawn.