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We present the construction of a deep multiwavelength point-spread-function-matched photometric catalog in the Ultra-Deep Survey (UDS) field following the final UKIDSS UDS release. The catalog includes photometry in 24 filters, from the MegaCam-uS0.38μm band to the Spitzer-IRAC 8μm band, over ∼0.9 deg²and with a 5σdepth of 25.3 AB in theK-band detection image. The catalog, containing ≈188,564 (136,235) galaxies at 0.2 <z< 8.0 with stellar mass$\log (M_{*}/M_{\odot })>8$andK-band total magnitudeK< 25.2 (24.3) AB, enables a range of extragalactic studies. We also provide photometric redshifts, corresponding redshift probability distributions, and rest-frame absolute magnitudes and colors derived using the template-fitting codeeazy-py. Photometric redshift errors are less than 3%−4% atz< 4 across the full brightness range in theKband and stellar mass range$8<\log (M_{*}/M_{\odot })<12$. Stellar population properties (e.g., stellar mass, star formation rate, dust extinction) are derived from the modeling of the spectral energy distributions using the codesFASTand Dense Basis.

 

We present a sample of 1165 extreme emission-line galaxies (EELGs) at 4 <z< 9 selected using James Webb Space Telescope (JWST) NIRCam photometry in the Cosmic Evolution Early Release Science (CEERS) program. We use a simple method to photometrically identify EELGs with Hβ+ [Oiii] (combined) or Hαemission of observed-frame equivalent width (EW) > 5000 Å. JWST/NIRSpec spectroscopic observations of a subset (34) of the photometrically selected EELGs validate our selection method: All spectroscopically observed EELGs confirm our photometric identification of extreme emission, including some cases where the spectral-energy-distribution-derived photometric redshifts are incorrect. We find that the medium-band F410M filter in CEERS is particularly efficient at identifying EELGs, both in terms of including emission lines in the filter and in correctly identifying the continuum between Hβ+ [Oiii] and Hαin the neighboring broadband filters. We present examples of EELGs that could be incorrectly classified as ultrahigh redshift (z> 12) as a result of extreme Hβ+ [Oiii] emission blended across the reddest photometric filters. We compare the EELGs to the broader (subextreme) galaxy population in the same redshift range and find that they are consistent with being the bluer, high-EW tail of a broader population of emission-line galaxies. The highest-EW EELGs tend to have more compact emission-line sizes than continuum sizes, suggesting that active galactic nuclei are responsible for at least some of the most extreme EELGs. The photometrically inferred emission-line ratios are consistent with interstellar medium conditions with high ionization and moderately low metallicity, consistent with previous spectroscopic studies.

 

We present measurements of the rest-frame UV spectral slope,β, for a sample of 36 faint star-forming galaxies atz∼ 9–16 discovered in one of the deepest JWST NIRCam surveys to date, the Next Generation Deep Extragalactic Exploratory Public Survey. We use robust photometric measurements for UV-faint galaxies (down toM_UV∼ −16), originally published in Leung et al., and measure values of the UV spectral slope via photometric power-law fitting to both the observed photometry and stellar population models obtained through spectral energy distribution (SED) fitting withBagpipes. We obtain a median and 68% confidence interval forβfrom photometric power-law fitting of${\beta }_{\mathrm{PL}}=-{2.7}_{-0.5}^{+0.5}$and from SED fitting,${\beta }_{\mathrm{SED}}=-{2.3}_{-0.1}^{+0.2}$for the full sample. We show that when only two to three photometric detections are available, SED fitting has a lower scatter and reduced biases than photometric power-law fitting. We quantify this bias and find that after correction the median${\beta }_{\mathrm{SED},\mathrm{corr}}=-{2.5}_{-0.2}^{+0.2}$. We measure physical properties for our galaxies withBagpipesand find that our faint ($M_{\mathrm{UV}}=-{18.1}_{-0.9}^{+0.7}$) sample is low in mass ($\log [M_{*}/M_{\odot }]={7.7}_{-0.5}^{+0.5}$), fairly dust-poor ($A_{\mathrm{v}}={0.1}_{-0.1}^{+0.2}$mag), and modestly young ($\log [\mathrm{age}]={7.8}_{-0.8}^{+0.2}$yr) with a median star formation rate of$\log (\mathrm{SFR})=-{0.3}_{-0.4}^{+0.4}{M}_{\odot }{\mathrm{yr}}^{-1}$. We find no strong evidence for ultrablue UV spectral slopes (β∼ −3) within our sample, as would be expected for exotically metal-poor (Z/Z_⊙< 10⁻³) stellar populations with very high Lyman continuum escape fractions. Our observations are consistent with model predictions that galaxies of these stellar masses atz∼ 9–16 should have only modestly low metallicities (Z/Z_⊙∼ 0.1–0.2).

 

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.

 

The selection of high-redshift galaxies often involves spectral energy distribution (SED) fitting to photometric data, an expectation for contamination levels, and measurement of sample completeness—all vetted through comparison to spectroscopic redshift measurements of a sub-sample. The first JWST data are now being taken over several extragalactic fields to different depths and across various areas, which will be ideal for the discovery and classification of galaxies out to distances previously uncharted. As spectroscopic redshift measurements for sources in this epoch will not be initially available to compare with the first photometric measurements ofz> 8 galaxies, robust photometric redshifts are of the utmost importance. Galaxies atz> 8 are expected to have bluer rest-frame ultraviolet (UV) colors than typically used model SED templates, which could lead to catastrophic photometric redshift failures. We use a combination of BPASS andCloudymodels to create a supporting set of templates that match the predicted rest-UV colors ofz> 8 simulated galaxies. We test these new templates by fitting simulated galaxies in a mock catalog, Yung et al., which mimic expected field depths and areas of the JWST Cosmic Evolution Early Release Science Survey (m_5σ∼ 28.6 over ∼100 arcmin²). We use EAZY to highlight the improvements in redshift recovery with the inclusion of our new template set and suggest criteria for selecting galaxies at 8 <z< 10 with the JWST, providing an important test case for observers venturing into this new era of astronomy.

 

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 present a sample of 30 massive (log( M * / M ⊙ ) > 11) z = 3–5 quiescent galaxies selected from the Spitzer-HETDEX Exploratory Large Area (SHELA) Survey and observed at 1.1 mm with Atacama Large Millimeter/submillimeter Array (ALMA) Band 6 observations. These ALMA observations would detect even modest levels of dust-obscured star formation, on the order of ∼20 M ⊙ yr −1 at z ∼ 4 at the 1 σ level, allowing us to quantify the amount of contamination from dusty star-forming sources in our quiescent sample. Starting with a parent sample of candidate massive quiescent galaxies from the Stevans et al. v1 SHELA catalog, we use the Bayesian B agpipes spectral energy distribution fitting code to derive robust stellar masses ( M * ) and star formation rates (SFRs) for these sources, and select a conservative sample of 36 candidate massive ( M * > 10 11 M ⊙ ) quiescent galaxies, with specific SFRs >2 σ below the Salmon et al. star-forming main sequence at z ∼ 4. Based on the ALMA imaging, six of these candidate quiescent galaxies show the presence of significant dust-obscured star formation, and thus were removed from our final sample. This implies a ∼17% contamination rate from dusty star-forming galaxies with our selection criteria using the v1 SHELA catalog. This conservatively selected quiescent galaxy sample at z = 3–5 will provide excellent targets for future observations to constrain better how massive galaxies can both grow and shut down their star formation in a relatively short period. 

We present a 0.3–4.5μm 16-band photometric catalog for the Spitzer/HETDEX Exploratory Large-Area (SHELA) survey. SHELA covers an ∼27 deg²field within the footprint of the Hobby–Eberly Telescope Dark Energy Experiment (HETDEX). Here we present new DECam imaging and anrizK_sband–selected catalog of four million sources extracted using a fully model-based approach. We validate our photometry by comparing with the model-based DECam Legacy Survey. We analyze the differences between model-based and aperture photometry by comparing with the previous SHELA catalog, finding that our model-based photometry can measure point sources to fainter fluxes and better capture the full emission of resolved sources. The catalog is 80% (50%) complete atriz∼ 24.7 (25.1) AB mag, and the optical photometry reaches a 5σdepth of ∼25.5 AB mag. We measure photometric redshifts and achieve a 1σscatter of Δz/(1 +z) of 0.04 with available spectroscopic redshifts at 0 ≤z≤ 1. This large-area, multiwavelength photometric catalog, combined with spectroscopic information from HETDEX, will enable a wide range of extragalactic science investigations.

 

We present a new rest-frame color–color selection method using synthetic us − gs and gs − is, (ugi)s colors to identify star-forming and quiescent galaxies. Our method is similar to the widely used U − V versus V − J (UVJ) diagram. However, UVJ suffers known systematics. Spectroscopic campaigns have shown that UVJ-selected quiescent samples at z ≳ 3 include ∼10%–30% contamination from galaxies with dust-obscured star formation and strong emission lines. Moreover, at z > 3, UVJ colors are extrapolated because the rest-frame band shifts beyond the coverage of the deepest bandpasses at <5 μm (typically Spitzer/IRAC 4.5 μm or future JWST/NIRCam observations). We demonstrate that (ugi)s offers improvements to UVJ at z > 3, and can be applied to galaxies in the JWST era. We apply (ugi)s selection to galaxies at 0.5 < z < 6 from the (observed) 3D-HST and UltraVISTA catalogs, and to the (simulated) JAGUAR catalogs. We show that extrapolation can affect (V − J)0 color by up to 1 mag, but changes ${({g}_{s}-{i}_{s})}_{0}$ color by ≤0.2 mag, even at z ≃ 6. While (ugi)s-selected quiescent samples are comparable to UVJ in completeness (both achieve ∼85%–90% at z = 3–3.5), (ugi)s reduces contamination in quiescent samples by nearly a factor of 2, from ≃35% to ≃17% at z = 3, and from ≃60% to ≃33% at z = 6. This leads to improvements in the true-to-false-positive ratio (TP/FP), where we find TP/FP ≳2.2 for (ugi)s at z ≃ 3.5 − 6, compared to TP/FP < 1 for UVJ-selected samples. This indicates that contaminants will outnumber true quiescent galaxies in UVJ at these redshifts, while (ugi)s will provide higher-fidelity samples. 

Abstract Recent studies have revealed a strong relation between the sample-averaged black hole (BH) accretion rate (BHAR) and star formation rate (SFR) among bulge-dominated galaxies—i.e., “lockstep” BH–bulge growth—in the distant universe. This relation might be closely connected to the BH–bulge mass correlation observed in the local universe. To further understand BH–bulge coevolution, we present Atacama Large Millimeter/submillimeter Array (ALMA) CO(2–1) or CO(3–2) observations of seven star-forming bulge-dominated galaxies at z = 0.5–2.5. Using the ALMA data, we detect significant (>3 σ ) CO emission from four objects. For our sample of seven galaxies, we measure (or constrain with upper limits) their CO line fluxes and estimate their molecular gas masses ( M gas ). We also estimate their stellar masses ( M star ) and SFRs, by modeling their spectral energy distributions. Using these physical properties, we derive the gas depletion timescales ( τ dep ≡ M gas /SFR) and compare them with the bulge/BH growth timescales ( τ grow ≡ M star /SFR ∼ M BH /BHAR). Our sample generally has τ dep shorter than τ grow by a median factor of ≳4, indicating that the cold gas will be depleted before significant bulge/BH growth takes place. This result suggests that BH–bulge lockstep growth is mainly responsible for maintaining the mass relation, not creating it. We note that our sample is small and limited to z < 2.5; JWST and ALMA will be able to probe to higher redshifts in the near future.