Search

Abstract Collisions between wildlife and aircraft, commonly referred to as wildlife strikes or bird strikes, are rare events that pose considerable safety and economic risks to the aviation industry. Given the potentially dramatic consequences of such events, airports scheduled for passenger service are required to conduct wildlife hazard assessments and implement wildlife hazard management plans for the purpose of mitigating wildlife strike risk. The evaluation of such management, however, is complicated by imperfect reporting that mediates the relationship between realized wildlife strike risk and wildlife strike metrics. In this paper, we shed light on such phenomena by investigating the staggered adoption of a federal wildlife hazards management program at joint-use airports across the contiguous United States. This research design allowed us to exploit variation in both management presence across airports, over time as well as variation in the quality of wildlife strike reporting within airports. As hypothesized, we found that wildlife hazards management intervention has a significant impact on the quality of reporting, as evidenced by a substantial increase in the number of civil strikes reported over the management period. Where pre-existing reporting mechanisms were more robust, however, we found that wildlife hazards management had a significant impact on realized wildlife strike risk as evidenced by a decrease in strike-induced economic damages among military aircraft. Overall, we found that the estimated economic benefits of the studied airport wildlife hazards management program were 7 times greater than the costs over the management period. Our results have important implications for the measurement of wildlife strike risk and the management of wildlife hazards at airports, as well as important insights pertaining to the use of observational data for causal inference, particularly in the context of risk management.

Abstract Introduction The disposal of regulated medical waste (RMW) in the healthcare setting can be both costly and environmentally harmful. Prior studies have found large amounts of waste disposed of in RMW containers are inappropriately placed. Few studies to date have investigated the efficacy of waste reduction practices in the dermatology setting. Methods This study aims to evaluate the effectiveness of a practice-wide intervention in reducing RMW in the outpatient dermatology setting. By performing daily waste audits and two concurrent educational interventions, the amount of RMW produced and percent of appropriately placed RMW will be measured. Further analysis will occur by comparing pre-intervention values to post-intervention values. Results The percentage of waste properly placed in RMW containers prior to any intervention was 11%. Following both educational interventions, the percentage of waste properly placed in RMW containers increased by 56.1% (CI 43.7–68.5%) and the percentage of total waste produced that was identified and disposed of as RMW decreased by 6.0% (95% CI 1.2–10.8%). Conclusion Our study provides practical data for dermatology providers to make small changes which can result in significant reductions of regulated medical waste, potentially providing benefits to the environment and cost-savings.

Abstract Introduction In patients admitted to the intensive care unit (ICU), muscle mass is inversely associated with mortality. Although muscle mass can be estimated with 24-h urinary creatinine excretion (UCE), its use for risk prediction in individual patients is limited because age-, sex-, weight- and length-specific reference values for UCE are lacking. The ratio between measured creatinine clearance (mCC) and estimated glomerular filtration rate (eGFR) might circumvent this constraint. The main goal was to assess the association of the mCC/eGFR ratio in ICU patients with all-cause hospital and long-term mortality. Methods The mCC/eGFR ratio was determined in patients admitted to our ICU between 2005 and 2021 with KDIGO acute kidney injury (AKI) stage 0–2 and an ICU stay ≥ 24 h. mCC was calculated from UCE and plasma creatinine and indexed to 1.73 m2. mCC/eGFR was analyzed by categorizing patients in mCC/eGFR quartiles and as continuous variable. Results Seven thousand five hundred nine patients (mean age 61 ± 15 years; 38% female) were included. In-hospital mortality was 27% in the lowest mCC/eGFR quartile compared to 11% in the highest quartile (P

Abstract Computational models can be at the basis of new powerful technologies for studying and classifying disorders like pre-eclampsia, where it is difficult to distinguish pre-eclamptic patients from non-pre-eclamptic based on pressure when patients have a track record of hypertension. Computational models now enable a detailed analysis of how pregnancy affects the cardiovascular system. Therefore, new non-invasive biomarkers were developed that can aid the classification of pre-eclampsia through the integration of six different measured non-invasive cardiovascular signals. Datasets of 21 pregnant women (no early onset pre-eclampsia, n = 12; early onset pre-eclampsia, n = 9) were used to create personalised cardiovascular models through computational modelling resulting in predictions of blood pressure and flow waveforms in all major and minor vessels of the utero-ovarian system. The analysis performed revealed that the new predictors PPI (pressure pulsatility index) and RI (resistance index) calculated in arcuate and radial/spiral arteries are able to differentiate between the 2 groups of women (t-test scores of p

Introduction Cigarette smoking and smoking-related lung disease are more common in rural (vs urban) areas of the United States (US). This study examined relationships between geographical location, cigarette risk perceptions, and current smoking among older adults who are at greatest risk of developing smoking-related lung disease. Methods The study was a secondary data analysis of 12126 respondents aged ≥40 years from Wave 5 of the Population Assessment of Tobacco and Health Study. Weighted descriptive statistics and Poisson regressions assessed current smoking (vs never or former) as a function of geographical location in a stepwise fashion, first unadjusted, then adjusting for sociodemographic characteristics, and finally for both sociodemographic characteristics and cigarette risk perceptions (4-item scale), in three separate models. Sensitivity analyses examined whether individual risk perceptions items had a greater impact on the association between geographical location and current smoking. Results Current smoking was more common among rural (20.6%) than urban (17.6%) residents. The risk ratio (RR) for rural (vs urban) residence on current smoking decreased from 1.17 (95% CI: 1.03–1.32) to 1.14 (95% CI: 1.01–1.29) to 1.08 (95% CI: 0.96–1.21) across the stepwise models. Lower cigarette risk perceptions confounded the rural-current smoking association and was an independent risk factor for smoking (adjusted RR, ARR=2.15; 95% CI: 1.94– 2.18). In sensitivity analyses, believing that cigarettes are very or extremely (vs somewhat, slightly, or not at all) harmful to health and agreeing (vs not agreeing) that secondhand smoke causes lung disease in people who do not smoke, confounded the rural-current smoking association whereas beliefs about smoking causing lung cancer or lung disease in people who smoke did not. Conclusions Lower cigarette risk perceptions among rural residents confounded the positive association between rural residence and current smoking. Results from sensitivity analyses highlight potential targets for communication campaigns aimed at promoting more accurate perceptions of the harmful health consequences of cigarette smoking.

Background: Dermatology journals play an essential role in the distribution and promotion of scientific and medical information. Despite this, there are little data on governance structure with respect to its editors, owners, and journal boards that oversee the day-to-day operations for these entities. Objective: This study aimed to explore the current governance structure of dermatology journals and best practice recommendations. Methods: The editors-in-chief of the major dermatology journals participated in an online survey of 29 questions to examine general statistics of each journal, open access model, governance structure, and process for editor selection or dismissal. Results: Of the 52 journal responses, 29 (55.8%) are society-owned journals with 19 (65.5%) primarily governed by a society board, while 18 (34.6%) have an advisory committee or alternative body. Most editor(s)-in-chief (56.9%) serve between 3- and 5-year terms, while 84.6% have the option of at least one renewal. Even though the selection, evaluation, and dismissal processes differed between the journals, generalized best practice recommendations were developed to help improve their overall organization and management. Conclusions: The oversight structure of dermatology journals varies, and some do not follow current best practice recommendations. Transparency regarding leadership, governance, and due process is needed to maintain editorial independence and integrity.

Abstract Management of immune thrombocytopenia (ITP) in dogs and cats is evolving, but there are no evidence‐based guidelines to assist clinicians with treatment decisions. Likewise, the overall goals for treatment of ITP have not been established. Immunosuppressive doses of glucocorticoids are the first line treatment, but optimal treatment regimens beyond glucocorticoids remain uncertain. Additional options include secondary immunosuppressive drugs such as azathioprine, modified cyclosporine, and mycophenolate mofetil, usually selected based on clinician preference. Vincristine, human IV immunoglobulin (hIVIg), and transfusion of platelet or red blood cell–containing products are often used in more severe cases. Splenectomy and thrombopoietin receptor agonists are usually reserved for refractory cases, but when and in which patient these modalities should be employed is under debate. To develop evidence‐based guidelines for individualized treatment of ITP patients, we asked 20 Population Intervention Comparison Outcome (PICO) format questions. These were addressed by 17 evidence evaluators using a literature pool of 288 articles identified by a structured search strategy. Evidence evaluators, using panel‐designed templates and data extraction tools, summarized evidence and created guideline recommendations. These were integrated by treatment domain chairs and then refined by iterative Delphi survey review to reach consensus on the final guidelines. In addition, 19 non‐PICO questions covering scenarios in which evidence was lacking or of low quality were answered by expert opinion using iterative Delphi surveys with panelist integration and refinement. Commentary was solicited from multiple relevant professional organizations before finalizing the consensus. The rigorous consensus process identified few comparative treatment studies, highlighting many areas of ITP treatment requiring additional studies. This statement is a companion manuscript to the ACVIM Consensus Statement on the Diagnosis of Immune Thrombocytopenia in Dogs and Cats.

BackgroundUnderstanding public opinions about emerging tobacco products is important to inform future interventions and regulatory decisions. Heated tobacco products (HTPs) are an emerging tobacco product category promoted by the tobacco industry as a “better alternative” to combustible cigarettes. Philip Morris International’s IQOS is leading the global HTP market and recently has been subject to important policy events, including the US Food and Drug Administration’s (FDA) modified-risk tobacco product (MRTP) authorization (July 2020) and the US import ban (November 2021). Although limited in their legal implications outside the United States, these policy events have been quoted in global news outlets and Philip Morris International’s promotional communications, showing how they may potentially impact global tobacco regulation. Given the impending return of IQOS to the US market, understanding how the policy events were received through social media discourse will provide valuable insights to inform global tobacco control policy. ObjectiveThis study aims to examine HTP-related social media discourse around important policy events. MethodsWe analyzed HTP-related posts on Twitter during the time period that included IQOS’s MRTP authorization in the United States and the US import ban, examining personal testimonial, news/information, and direct marketing/retail tweets separately. We also examined how the tweets discussed health and policy. A total of 10,454 public English tweets (posted from June 2020 to December 2021) were collected using HTP-related keywords. We randomly sampled 2796 (26.7%) tweets and conducted a content analysis. We used pairwise co-occurrence analyses to evaluate connections across themes. ResultsTweet volumes peaked around IQOS-related policy events. Among all tweets, personal testimonials were the most common (1613/2796, 57.7%), followed by news/information (862/2796, 30.8%) and direct marketing/retail (321/2796, 11%). Among personal testimonials, more tweets were positive (495/1613, 30.7%) than negative (372/1613, 23.1%), often comparing the health risks of HTPs with cigarettes (402/1613, 24.9%) or vaping products (252/1613, 15.6%). Approximately 10% (31/321) of the direct marketing/retail tweets promoted international delivery, suggesting cross-border promotion. More than a quarter of tweets (809/2796, 28.9%) discussed US and global policy, including misinterpretation about IQOS being a “safer” tobacco product after the US FDA’s MRTP authorization. Neutral testimonials mentioning the IQOS brand (634/1613, 39.3%) and discussing policy (378/1613, 23.4%) showed the largest pairwise co-occurrence. ConclusionsResults suggest the need for careful communication about the meaning of MRTP authorizations and relative risks of tobacco products. Many tweets expressed HTP-favorable opinions referring to reduced health risks, even though the US FDA has denied marketing of the HTP with reduced risk claims. The popularity of social media as an information source with global reach poses unique challenges in health communication and health policies. While many countries restrict tobacco marketing via the web, our results suggest that retailers may circumvent such regulations by operating overseas.

Abstract Smoking may increase the risk of diabetic foot disease and ulceration. It does so by impairing glycaemic control and promoting the formation of advanced glycated end-products. Additionally, smoking is known to delay surgical wound healing and accelerate peripheral arterial disease. We aimed to determine whether toe pressures differed in smokers with a foot ulcer, when compared to non-smokers and ex-smokers, as well as ulcer outcomes at 12 months, among patients attending Blacktown Hospital High Risk Foot Service (HRFS). This study is a retrospective analysis of our prospectively collected clinic database. Eligible participants were adults attending the HRFS between June 2020 and April 2022. Participants were included if they had an ulcer, at least one systolic toe pressure reading completed at their initial visit and attended at least one follow-up visit. Participants were followed until healing, loss to follow-up or a minimum of 12 months. A total of 195 participants were included; 36 smokers, 82 ex-smokers, and 77 controls who had never smoked. Smoking status was by self-report. Current smokers were significantly younger at initial presentation (p = .002) and tended towards lower socioeconomic status (p = .067). Current smokers were significantly more likely to have ischaemic grade 3 toe pressures (

Objetivo: verificar las disparidades de ingresos salariales de género en Colombia entre jefes de hogar, considerando factores como el nivel educativo, la edad, la experiencia laboral y el estado civil. Además, buscó determinar cómo persistían las diferencias salariales entre hombres y mujeres, incluso cuando tenían un nivel educativo similar. Diseño/Metodología: se desarrollaron modelos de regresión lineal múltiple que incluían interacciones entre las variables de género y nivel educativo. Además, se utilizaron microdatos recientes de la Encuesta de Calidad de Vida del Departamento Administrativo Nacional de Estadística (DANE) con el fin de proporcionar una base sólida y actualizada para el análisis. Resultados: uno de los hallazgos más significativos de este estudio fue que en Colombia existía una disparidad salarial de género que aumentaba a medida que se incrementaba el nivel educativo. Este resultado subrayó la necesidad urgente de trabajar reducir esta diferencia y así mitigar su impacto socioeconómico en general. Conclusiones: el estudio concluye que es imperativo implementar políticas y estrategias que aborden estas disparidades salariales para promover una mayor equidad de género en el ámbito laboral. Originalidad: Esta investigación proporciona una visión integral de las disparidades salariales de género en Colombia, utilizando un enfoque cuantitativo robusto y datos actualizados. Su originalidad radica en identificar la creciente disparidad salarial con el aumento del nivel educativo, lo cual no solo refuerza la importancia de políticas de equidad de género, sino que también destaca la necesidad de intervenciones específicas en el ámbito educativo y laboral.

Abstract Introduction The environmental impact of holding in-person academic conferences and continuing medical education (CME) programs can be significant. In-person conferences provide a unique social and professional platform to engage in networking and foster professional development; however, there is an opportunity for hybrid and virtual platforms to provide CME for broader audiences looking to improve their clinical skills and strengthen their knowledge base. This study seeks to describe the reduction in carbon emissions associated with a webinar hosted by an online dermatology-focused medical education platform. Methods This cross-sectional study used the location of deidentified virtual attendees of a webinar to predict the carbon emissions produced if attendees had instead traveled to the location of the most recent Integrative Dermatology Symposium (Sacramento, CA). Following collection of each virtual attendee’s location, the mode of transportation was predicted on the basis of each participant’s distance to the conference. Results The estimated carbon emissions were calculated for 576 participants. The total estimated, unadjusted carbon emissions for both attendees predicted to fly or drive was 370,100 kg CO2. The emissions produced per participant from those expected to fly to an in-person CME after adjusting for all additional passengers on every flight were 4.5 kg CO2. The emissions produced per participant from those expected to drive were 42.7 kg CO2. Conclusion The use of a virtual CME webinar led to a significant reduction in travel-related carbon dioxide emissions when compared to running the same program in-person event. When accounting for all passengers traveling via plane on any flight, driving to an event produced more emissions per participant than flying.

Abstract Background NGAL and Cystatin C (CysC) as biomarkers for the early detection of AKI are subject to both pathophysiological, as well as patient related heterogeneity. The aim of this study was to investigate the timeline of plasma levels of NGAL and CysC during the first seven days of ICU admission in a mixed ICU population and to relate these to AKI severity during ICU stay. Via these means we aimed to bring clarity to the previously reported heterogeneity of these renal biomarkers. Methods Prospective Observation Cohort. Consecutive patients admitted to adult ICU at an academic hospital in the Netherlands between 18-02-2014 and 31-03-2014 were included. Urine output, serum creatinine, plasma NGAL and CysC were recorded during the first seven days of ICU admission. Biomarker expression was analyzed based on KDIGO score and time of AKI diagnosis. Results 335 patients were included, 110 met KDIGO criteria for AKI. NGAL and CysC plasma levels were higher in AKI patients compared to non-AKI, high variability in individual values resulted in 56% of AKI patients having a false negative, and 32% of non-AKI patients having a false positive. Individual biomarker levels were variable, and no pattern based on KDIGO score was observed. Conclusions Plasma NGAL and CysC as biomarkers for the early AKI detection may be subject to pathophysiological, and patient related heterogeneity. Further understanding of individual biomarker profiles may help in their application amongst mixed ICU populations. Trial Registration The need for informed consent was waived by the Institutional Ethical Review Board of the University Medical Center Groningen (METc 2013 − 174) by Prof. dr. W.A. Kamps on May 17th 2013.

Sex-based differences in immune cell composition and function can contribute to distinct adaptive immune responses. Prior work has quantified these differences in peripheral blood, but little is known about sex differences within human lymphoid tissues. Here, we characterized the composition and phenotypes of adaptive immune cells from male and female ex vivo tonsils and evaluated their responses to influenza antigens using an immune organoid approach. In a pediatric cohort, female tonsils had more memory B cells compared to male tonsils direct ex vivo and after stimulation with live-attenuated but not inactivated vaccine, produced higher influenza-specific antibody responses. Sex biases were also observed in adult tonsils but were different from those measured in children. Analysis of peripheral blood immune cells from in vivo vaccinated adults also showed higher frequencies of tissue homing CD4 T cells in female participants. Together, our data demonstrate that distinct memory B and T cell profiles are present in male vs. female lymphoid tissues and peripheral blood respectively and suggest that these differences may in part explain sex biases in response to vaccines and viruses.

Altered apolipoprotein kinetics play a critical role in promoting dyslipidemia and atherogenesis. Human apolipoprotein kinetics have been extensively evaluated, but similar studies in mice are hampered by the lack of robust methods suitable for the small amounts of blood that can be collected at sequential time points from individual mice. We describe a targeted liquid chromatography tandem mass spectrometry method for simultaneously quantifying the stable isotope enrichment of several apolipoproteins represented by multiple peptides in serial blood samples (15 μl each) obtained after retro-orbital injection of 13C6,15N2-lysine (Lys8) in mice. We determined apolipoprotein fractional clearance rates (FCRs) and production rates (PRs) in WT mice and in two genetic models widely used for atherosclerosis research, LDL receptor–deficient (Ldlr−/−) and apolipoprotein E–deficient (Apoe−/−) mice. Injection of Lys8 produced a unique and readily detectable mass shift of labeled compared with unlabeled peptides with sensitivity allowing robust kinetics analyses. Ldlr−/− mice showed slower FCRs of APOA1, APOA4, total APOB, APOB100, APOCs, APOE and APOM, while FCRs of APOA1, APOB100, APOC2, APOC3, and APOM were not lower in Apoe−/− mice versus WT mice. APOE PR was increased in Ldlr−/− mice, and APOB100 and APOA4 PRs were reduced in Apoe−/− mice. Thus, our method reproducibly quantifies plasma apolipoprotein kinetics in different mouse models. The method can easily be expanded to include a wide range of proteins in the same biospecimen and should be useful for determining the kinetics of apolipoproteins in animal models of human disease.

Background In recent years, self‐expanding technology to treat pulmonary regurgitation in the native right ventricular outflow tract became Food and Drug Administration approved in the United States and is now routinely used. The current practice for selection of patients who are candidates for these devices includes screening for “anatomic fit,” performed by each of the manufacturing companies. Our study aims to validate the use of virtual reality (VR) as a tool for local physician‐led screening of patients. Methods and Results This retrospective study from Children's Hospital Colorado included patients who underwent pulmonary valve replacement and had screening for a Harmony TPV or Alterra Prestent performed between September 2020 and January 2022. The data from the commercial companies’ dedicated analysis for self‐expanding transcatheter pulmonary valve frames evaluation with perimeter analysis were collected. VR simulation was performed blinded by 2 congenital interventional cardiologists using Elucis VR software and an Oculus Quest 2 headset. Among the 27 evaluated cases, the use of a self‐expandable valve was recommended by companies’ dedicated analysis in 23 cases (85.2%), by VR assessment in 26 cases (96.3), and finally implanted in 25 cases (92.6%). Regarding the level of agreement, both modalities (manufacturer and VR) were good at screening‐in patients who received a self‐expanding valve (100% versus 96.1%). When it came to screening‐out the patients, VR presented good capacity to accurately classify nonsuitable patients (50% versus 100%). Conclusions Our institutional experience with VR transcatheter pulmonary valve implantation planning accurately predicted clinical outcomes. This paves the way for routine use of VR in patient selection for self‐expanding valve technologies.

The mass–metallicity relation provides crucial insights into the baryon cycle in galaxies and strong constraints on galaxy formation models. We use JWST NIRSpec observations from the UNCOVER program to measure the gas-phase metallicity in a sample of eight galaxies during the epoch of reionization at z = 6–8. Thanks to the strong lensing of the galaxy cluster Abell 2744, we are able to probe extremely low stellar masses between 10 ^6 and 10 ^8 M _⊙ . Using strong-line diagnostics and the most recent JWST calibrations, we derive extremely low oxygen abundances in the range of 12 + log(O/H) = 6.7–7.8. By combining this sample with more massive galaxies at similar redshifts, we derive a best-fit relation of 12 + log(O/H) = $-{0.076}_{-0.03}^{+0.03}\times {(\mathrm{log}({M}_{\star }))}^{2}+{1.61}_{-0.52}^{+0.52}$ × $\mathrm{log}({M}_{\star })-{0.26}_{-0.10}^{+0.10}$ , which becomes steeper than determinations at z ∼ 3–6 toward low-mass galaxies. Our results show a clear redshift evolution in the overall normalization of the relation, galaxies at higher redshift having significantly lower metallicities at a given mass. A comparison with theoretical models provides important constraints on which physical processes, such as metal mixing, star formation or feedback recipes, are important in reproducing the observations. Additionally, these galaxies exhibit star formation rates that are higher by a factor of a few to tens compared to extrapolated relations at similar redshifts or theoretical predictions of main-sequence galaxies, pointing to a recent burst of star formation. All these observations are indicative of the highly stochastic star formation and interstellar medium enrichment expected in these low-mass systems, suggesting that feedback mechanisms in high- z dwarf galaxies might be different from those in place at higher masses.

It is well known that almost all isolated dwarf galaxies are actively forming stars. We report the discovery of dw1322m2053 (nicknamed Hedgehog), an isolated quiescent dwarf galaxy at a distance of 2.40 ± 0.15 Mpc with a stellar mass of M _⋆ ≈ 10 ^5.8 M _⊙ . The distance is measured using surface brightness fluctuations with both Legacy Surveys and deep Magellan/IMACS imaging data. Hedgehog is 1.7 Mpc from the nearest galaxy group, Centaurus A, and has no neighboring galaxies within 1 Mpc, making it one of the most isolated quiescent dwarf galaxies at this stellar mass. It has a red optical color and early-type morphology and shows no UV emission. This indicates that Hedgehog has an old stellar population and no ongoing star formation. Compared with other quiescent dwarfs in the Local Group and Local Volume, Hedgehog appears smaller in size for its luminosity but is consistent with the mass–size relations. Hedgehog might be a backsplash galaxy from the Centaurus A group, but it could also have been quenched in the field by ram pressure stripping in the cosmic web, reionization, or internal processes such as supernova and stellar feedback. Future observations are needed to fully unveil its formation, history, and quenching mechanisms.

The identification of red, apparently massive galaxies at z > 7 in early James Webb Space Telescope (JWST) photometry suggests a strongly accelerated time line compared to standard models of galaxy growth. A major uncertainty in the interpretation is whether the red colors are caused by evolved stellar populations, dust, or other effects such as emission lines or active galactic nuclei (AGNs). Here we show that three of the massive galaxy candidates at z = 6.7–8.4 have prominent Balmer breaks in JWST/NIRSpec spectroscopy from the RUBIES program. The Balmer breaks demonstrate unambiguously that stellar emission dominates at λ _rest = 0.4 μ m and require formation histories extending hundreds of millions of years into the past in galaxies only 600–800 Myr after the big bang. Two of the three galaxies also show broad Balmer lines, with H β FWHM > 2500 km s ^−1 , suggesting that dust-reddened AGNs contribute to, or even dominate, the spectral energy distributions of these galaxies at λ _rest ≳ 0.6 μ m. All three galaxies have relatively narrow [O iii ] lines, seemingly ruling out a high-mass interpretation if the lines arise in dynamically relaxed, inclined disks. Yet the inferred masses also remain highly uncertain. We model the high-quality spectra using Prospector to decompose the continuum into stellar and AGN components and explore limiting cases in stellar/AGN contribution. This produces a wide range of possible stellar masses, spanning M _⋆ ∼ 10 ^9 −10 ^11 M _⊙ . Nevertheless, all fits suggest a very early and rapid formation, most of which follow with a truncation in star formation. Potential origins and evolutionary tracks for these objects are discussed, from the cores of massive galaxies to low-mass galaxies with overmassive black holes. Intriguingly, we find all of these explanations to be incomplete; deeper and redder data are needed to understand the physics of these systems.

We present a measurement of the low-mass quiescent size–mass relation at cosmic noon (1 < z < 3) from the JWST PRIMER and UNCOVER treasury surveys, which highlights two distinct classes of quiescent galaxies. While the massive population is well studied at these redshifts, the low-mass end has been previously underexplored due to a lack of observing facilities with sufficient sensitivity and spatial resolution. We select a conservative sample of low-mass quiescent galaxy candidates using rest-frame UVJ colors and specific star formation rate criteria and measure galaxy morphology in both rest-frame UV/optical wavelengths (F150W) and rest-frame near-infrared (F444W). We confirm an unambiguous flattening of the low-mass quiescent size–mass relation, which results from the separation of the quiescent galaxy sample into two distinct populations at $\mathrm{log}({M}_{\star }/{M}_{\odot })\sim 10.3$ : low-mass quiescent galaxies that are notably younger and have disky structures, and massive galaxies consistent with spheroidal morphologies and older median stellar ages. These separate populations imply mass quenching dominates at the massive end while other mechanisms, such as environmental or feedback-driven quenching, form the low-mass end. This stellar mass-dependent slope of the quiescent size–mass relation could also indicate a shift from size growth due to star formation (low masses) to growth via mergers (massive galaxies). The transition mass between these two populations also corresponds with other dramatic changes and characteristic masses in several galaxy evolution scaling relations (e.g., star formation efficiency, dust obscuration, and stellar-to-halo mass ratios), further highlighting the stark dichotomy between low-mass and massive galaxy formation.

Active galactic nuclei (AGN) light curves observed with different wave bands show that the variability in longer wavelength bands lags the variability in shorter wavelength bands. Measuring these lags, or reverberation mapping, is used to measure the radial temperature profile and extent of AGN disks, typically with a reprocessing model that assumes X-rays are the main driver of the variability in other wavelength bands. To demonstrate how this reprocessing works with realistic accretion disk structures, we use 3D local shearing box multifrequency radiation magnetohydrodynamic simulations to model the UV-emitting region of an AGN disk, which is unstable to the magnetorotational instability and convection. At the same time, we inject hard X-rays (>1 keV) into the simulation box to study the effects of X-ray irradiation on the local properties of the turbulence and the resulting variability of the emitted UV light curve. We find that disk turbulence is sufficient to drive intrinsic variability in emitted UV light curves and that a damped random walk model is a good fit to this UV light curve for timescales >5 days. Meanwhile, X-ray irradiation has negligible impact on the power spectrum of the emitted UV light curve. Furthermore, the injected X-ray and emitted UV light curves are only correlated if there is X-ray variability on timescales >1 day, in which case we find a correlation coefficient r = 0.34. These results suggest that if the opacity for hard X-rays is scattering dominated as in the standard disk model, hard X-rays are not the main driver of reverberation signals.

Active galactic nuclei (AGN) are the signposts of black hole growth, and likely play an important role in galaxy evolution. An outstanding question is whether AGN of different spectral types indicate different evolutionary stages in the coevolution of black holes and galaxies. We present the angular correlation function between an AGN sample selected from Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) optical photometry and Wide-field Infrared Survey Explorer mid-IR photometry and a luminous red galaxy (LRG) sample from HSC-SSP. We investigate AGN clustering strength as a function of luminosity and spectral features across three independent HSC fields totaling ∼600 deg ^2 , for z ∈ 0.6 −1.2 and AGN with L _6 _ μ _m > 3 × 10 ^44 erg s ^−1 . There are ∼28,500 AGN and ∼1.5 million LRGs in our primary analysis. We determine the average halo mass for the full AGN sample ( M _h ≈ 10 ^12.9 h ^−1 M _⊙ ), and note that it does not evolve significantly as a function of redshift (over this narrow range) or luminosity. We find that, on average, unobscured AGN ( M _h ≈ 10 ^13.3 h ^−1 M _⊙ ) occupy ∼4.5× more massive halos than obscured AGN ( M _h ≈ 10 ^12.6 h ^−1 M _⊙ ), at 5 σ statistical significance using 1D uncertainties, and at 3 σ using the full covariance matrix, suggesting a physical difference between unobscured and obscured AGN, beyond the line-of-sight viewing angle. Furthermore, we find evidence for a halo mass dependence on reddening level within the Type I AGN population, which could support the existence of a dust-obscured phase. However, we also find that quite small systematic shifts in the redshift distributions of the AGN sample could explain current and previously observed differences in M _h .

The shallow potential wells of star-forming dwarf galaxies make their surrounding circumgalactic and intergalactic medium (CGM/IGM) sensitive laboratories for studying the inflows and outflows thought to regulate galaxy evolution. We present new absorption-line measurements in quasar sight lines, probing within projected distances of

In this paper, we describe the “Medium Bands, Mega Science” JWST Cycle 2 survey (JWST-GO-4111) and demonstrate the power of these data to reveal both the spatially integrated and spatially resolved properties of galaxies from the local Universe to the era of cosmic dawn. Executed in 2023 November, MegaScience obtained ∼30 arcmin ^2 of deep multiband NIRCam imaging centered on the z ∼ 0.3 A2744 cluster, including 11 medium-band filters and the two shortest-wavelength broadband filters, F070W and F090W. Together, MegaScience and the UNCOVER Cycle 1 treasury program provide a complete set of deep (∼28–30 mag _AB ) images in all NIRCam medium- and broadband filters. This unique data set allows us to precisely constrain photometric redshifts, map stellar populations and dust attenuation for large samples of distant galaxies, and examine the connection between galaxy structures and formation histories. MegaScience also includes ∼17 arcmin ^2 of NIRISS parallel imaging in two broadband and four medium-band filters from 0.9 to 4.8 μ m, expanding the footprint where robust spectral energy distribution (SED) fitting is possible. We provide example SEDs and multiband cutouts at a variety of redshifts, and use a catalog of JWST spectroscopic redshifts to show that MegaScience improves both the scatter and catastrophic outlier rate of photometric redshifts by factors of 2–3. Additionally, we demonstrate the spatially resolved science enabled by MegaScience by presenting maps of the [O iii ] line emission and continuum emission in three spectroscopically confirmed z > 6 galaxies. We show that line emission in reionization-era galaxies can be clumpy, extended, and spatially offset from continuum emission, implying that galaxy assembly histories are complex even at these early epochs. We publicly release fully reduced mosaics and photometric catalogs for both the NIRCam primary and NIRISS parallel fields ( http://jwst-uncover.github.io/megascience ).

Poststarburst galaxies (PSBs) are young quiescent galaxies that have recently experienced a rapid decrease in star formation, allowing us to probe the fast-quenching period of galaxy evolution. In this work, we obtained Hubble Space Telescope (HST)/WFC3 F110W imaging to measure the sizes of 171 massive ( $\mathrm{log}({M}_{* }/{M}_{\odot })\sim \,11)$ spectroscopically identified PSBs at 1 < z 1.3 selected from the DESI Survey Validation luminous red galaxy sample. This statistical sample constitutes an order of magnitude increase from the ∼20 PSBs with space-based imaging and deep spectroscopy. We perform structural fitting of the target galaxies with pysersic and compare them to quiescent and star-forming galaxies in the 3D-HST survey. We find that these PSBs are more compact than the general population of quiescent galaxies, lying systematically ∼0.1 dex below the established size–mass relation. However, their central surface mass densities are similar to those of their quiescent counterparts ( $\,{\rm{log}}({{\rm{\Sigma }}}_{1{\rm{kpc}}}/({M}_{\odot }\,{{\rm{kpc}}}^{-2}))\sim 10.1$ ). These findings are easily reconciled by later ex situ growth via minor mergers or a slight progenitor bias. These PSBs are round in projection ( b / a _median ∼ 0.8), suggesting that they are primarily spheroids, not disks, in 3D. We find no correlation between the time since quenching and light-weighted PSB sizes or central densities. This disfavors apparent structural growth due to the fading of centralized starbursts in this galaxy population. Instead, we posit that the fast quenching of massive galaxies at this epoch occurs preferentially in galaxies with preexisting compact structures.

The James Webb Space Telescope (JWST) has uncovered a ubiquitous population of dust-obscured compact sources at z ≳ 4. Many of these objects exhibit signs of active galactic nucleus (AGN) activity, making their study crucial for understanding the formation of supermassive black holes (SMBHs) and their growth with host galaxies. In this work, we examine low and medium-resolution JWST/NIRSpec spectra from the JADES GTO public data release in the GOODS-N field of a red, luminous ( M _B ∼ −22.2 mag) and compact ( 4000 Å) continuum of this source is strongly dominated by a massive (log _10 [ M _* / M _⊙ ] ∼ 10.6), quenched (log _10 [sSFR/yr ^−1 ] < −11) galaxy, as indicated by the clear presence of a Balmer break and stellar absorption lines. Star formation history modeling reveals a starburst episode followed by rapid quenching about 200 Myr ago. The spectrum shows extremely broad (FWHM ∼2500 km s ^−1 ) H α emission and elevated optical line ratios, indicating an actively accreting SMBH. Moreover, our work has potentially revealed clear AGN signatures in the rest-UV in little red dots for the first time via the detection of a strong Ly α emission and a broad Mg ii doublet. The derived black hole mass of log _10 ( M _BH / M _⊙ ) ∼ 7.3 results in M _BH / M _* ∼ 0.04%, consistent with the local relations, unlike the elevated ratios in other high- z reddened AGN. Finally, we use JWST data from AGN at z = 4–10 to explore an evolutionary link between high- z reddened AGN, early quiescent galaxies, and local ellipticals.

Using medium-band imaging from the newly released Merian Survey, we conduct a nonparametric morphological analysis of H α emission maps and stellar continua for a sample of galaxies with $8\lesssim \mathrm{log}({M}_{\star }/{M}_{\odot })\lt 10.3$ at 0.064 < z < 0.1. We present a novel method for estimating the stellar continuum emission through the Merian Survey’s N708 medium-band filter, which we use to measure H α emission and produce H α maps for our sample of galaxies with seven-band Merian photometry and available spectroscopy. We measure nonparametric morphological statistics for the H α and stellar continuum images, explore how the morphology of the H α differs from the continuum, and investigate how the parameters evolve with the galaxies’ physical properties. In agreement with previous results for more massive galaxies, we find that the asymmetry of the stellar continuum increases with specific star formation rate (sSFR), and we extend the trend to lower masses, also showing that it holds for the asymmetry of the H α emission. We find that the lowest-mass galaxies with the highest sSFR have H α emission that is consistently heterogeneous and compact, while the less active galaxies in this mass range have H α emission that appears diffuse. At higher masses, our data do not span a sufficient range in sSFR to evaluate whether similar trends apply. We conclude that high sSFRs in low-mass galaxies likely result from dynamical instabilities that compress a galaxy’s molecular gas to a dense region near the center.

Quasar feedback is a key ingredient in shaping galaxy evolution. A rare population of extremely red quasars (ERQs) at z = 2−3 are often associated with high-velocity [O iii ] λ 5008 outflows and may represent sites of strong feedback. In this paper, we present an X-ray study of 50 ERQs to investigate the link between the X-ray and outflow properties of these intriguing objects. Using hardness ratio analysis, we confirm that the ERQs are heavily obscured systems with gas column density reaching N _H = 10 ^23−24 cm ^−2 . We identify 20 X-ray-nondetected ERQs at high mid-infrared (MIR) luminosities of ν L _ν _,6 _ μ _m ≳ 3 × 10 ^46 erg s ^−1 . By stacking the X-ray observations, we find that the nondetected ERQs are on average underluminous in X-rays by a factor of ∼10 for their MIR luminosities. We consider such X-ray weakness to be due to both heavy gas absorption and intrinsic factors. Moreover, we find that the X-ray-weak sources also display higher-velocity outflows. One option to explain this trend is that weaker X-rays facilitate more vigorous line-driven winds, which then accelerate the [O iii ]-emitting gas to kiloparsec scales. Alternatively, super-Eddington accretion could also lead to intrinsic X-ray weakness and more powerful continuum-driven outflow.

We report the spectroscopic confirmation of a massive ( $\mathrm{log}({M}_{\star }/{M}_{\odot })=10.34{\pm }_{0.07}^{0.06}$ ), Hubble Space Telescope–dark ( m _F150W − m _F444W = 3.6) quiescent galaxy at z _spec = 3.97 in the UNCOVER survey. NIRSpec/PRISM spectroscopy and a nondetection in deep Atacama Large Millimeter/submillimeter Array imaging surprisingly reveals that the galaxy is consistent with a low (

In this paper we describe the survey design for the Ultradeep NIRSpec and NIRCam Observations before the Epoch of Reionization (UNCOVER) Cycle 1 JWST Treasury program, which executed its early imaging component in 2022 November. The UNCOVER survey includes ultradeep (∼29–30AB) imaging of ∼45 arcmin ^2 on and around the well-studied A2744 galaxy cluster at z = 0.308 and will follow up ∼500 galaxies with extremely deep low-resolution spectroscopy with the NIRSpec/PRISM during the summer of 2023, with repeat visits in summer 2024. We describe the science goals, survey design, target selection, and planned data releases. We also present and characterize the depths of the first NIRCam imaging mosaic, highlighting previously unparalleled resolved and ultradeep 2–4 μ m imaging of known objects in the field. The UNCOVER primary NIRCam mosaic spans 28.8 arcmin ^2 in seven filters (F115W, F150W, F200W, F277W, F356W, F410M, and F444W) and 16.8 arcmin ^2 in our NIRISS parallel (F115W, F150W, F200W, F356W, and F444W). To maximize early community use of the Treasury data set, we publicly release the full reduced mosaics of public JWST imaging including 45 arcmin ^2 NIRCam and 17 arcmin ^2 NIRISS mosaics on and around the A2744 cluster, including the Hubble Frontier Field primary and parallel footprints.

The supermassive black holes ( M _BH ∼ 10 ^6 –10 ^10 M _⊙ ) that power luminous active galactic nuclei (AGNs), i.e., quasars, generally show a correlation between thermal disk emission in the ultraviolet (UV) and coronal emission in hard X-rays. In contrast, some “massive” black holes (mBHs; M _BH ∼ 10 ^5 –10 ^6 M _⊙ ) in low-mass galaxies present curious X-ray properties with coronal radiative output up to 100× weaker than expected. To examine this issue, we present a pilot study incorporating Very Large Array radio observations of a sample of 18 high-accretion-rate (Eddington ratios L _bol / L _Edd > 0.1), mBH-powered AGNs ( M _BH ∼ 10 ^6 M _⊙ ) with Chandra X-ray coverage. Empirical correlations previously revealed in samples of radio-quiet, high-Eddington AGNs indicate that the radio–X-ray luminosity ratio, L _R / L _X , is approximately constant. Through multiwavelength analysis, we instead find that the X-ray-weaker mBHs in our sample tend toward larger values of L _R / L _X even though they remain radio-quiet per their optical–UV properties. This trend results in a tentative but highly intriguing correlation between L _R / L _X and X-ray weakness, which we argue is consistent with a scenario in which X-rays may be preferentially obscured from our line of sight by a “slim” accretion disk. We compare this observation to weak emission-line quasars (AGNs with exceptionally weak broad-line emission and a significant X-ray-weak fraction) and conclude by suggesting that our results may offer a new observational signature for finding high-accretion-rate AGNs.

We study the black hole mass–host galaxy stellar mass relation, M _BH – M _* , of a sample of z < 4 optically variable active galactic nuclei (AGNs) in the COSMOS field. The parent sample of 491 COSMOS AGNs were identified by optical variability from the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) program. Using publicly available catalogs and spectra, we consolidate their spectroscopic redshifts and estimate virial black hole masses using broad-line widths and luminosities. We show that variability searches with deep, high-precision photometry like the HSC-SSP can identity AGNs in low-mass galaxies up to z ∼ 1. However, their black holes are more massive given their host galaxy stellar masses than predicted by the local relation for active galaxies. We report that z ∼ 0.5–4 variability-selected AGNs are meanwhile more consistent with the M _BH – M _* relation for local inactive early-type galaxies. This result is in agreement with most previous studies of the M _BH – M _* relation at similar redshifts and indicates that AGNs selected from variability are not intrinsically different from the broad-line Type 1 AGN population at similar luminosities. Our results demonstrate the need for robust black hole and stellar mass estimates for intermediate-mass black hole candidates in low-mass galaxies at similar redshifts to anchor this scaling relation. Assuming that these results do not reflect a selection bias, they appear to be consistent with self-regulated feedback models wherein the central black hole and stars in galaxies grow in tandem.

Observations with the James Webb Space Telescope (JWST) have uncovered numerous faint active galactic nuclei (AGN) at z ∼ 5 and beyond. These objects are key to our understanding of the formation of supermassive black holes (SMBHs), their coevolution with host galaxies, as well as the role of AGN in cosmic reionization. Using photometric colors and size measurements, we perform a search for compact red objects in an array of blank deep JWST/NIRCam fields totaling ∼640 arcmin ^2 . Our careful selection yields 260 reddened AGN candidates at 4 < z _phot < 9, dominated by a point-source-like central component (〈 r _eff 〉 < 130 pc) and displaying a dichotomy in their rest-frame colors (blue UV and red optical slopes). Quasar model fitting reveals our objects to be moderately dust-extincted ( A _V ∼ 1.6), which is reflected in their inferred bolometric luminosities of L _bol = 10 ^44–47 erg s ^−1 and fainter UV magnitudes M _UV ≃ −17 to −22. Thanks to the large areas explored, we extend the existing dusty AGN luminosity functions to both fainter and brighter magnitudes, estimating their number densities to be ×100 higher than for UV-selected quasars of similar magnitudes. At the same time, they constitute only a small fraction of all UV-selected galaxies at similar redshifts, but this percentage rises to ∼10% for M _UV ∼ − 22 at z ∼ 7. Finally, assuming a conservative case of accretion at the Eddington rate, we place a lower limit on the SMBH mass function at z ∼ 5, finding it to be consistent with both theory and previous JWST observations.

We present the final data from the Sloan Digital Sky Survey (SDSS) Reverberation Mapping (RM) project, a precursor to the SDSS-V Black Hole Mapper RM program. This data set includes 11 yr photometric and 7 yr spectroscopic light curves for 849 broad-line quasars over a redshift range of 0.1 < z < 4.5 and a luminosity range of L _bol = 10 ^44−47.5 erg s ^−1 , along with spectral and variability measurements. We report 23, 81, 125, and 110 RM lags (relative to optical continuum variability) for broad H α , H β , Mg ii , and C iv using the SDSS-RM sample, spanning much of the luminosity and redshift ranges of the sample. Using 30 low-redshift RM active galactic nuclei with dynamical-modeling black hole masses, we derive a new estimate of the average virial factor of $\left\langle \mathrm{log}f\right\rangle =0.62\pm 0.07$ for the line dispersion measured from the rms spectrum. The intrinsic scatter of individual virial factors is 0.31 ± 0.07 dex, indicating a factor of 2 systematic uncertainty in RM black hole masses. Our lag measurements reveal significant R – L relations for H β and Mg ii at high redshift, consistent with the latest measurements based on heterogeneous samples. While we are unable to robustly constrain the slope of the R – L relation for C iv given the limited dynamic range in luminosity, we found substantially larger scatter in C iv lags at fixed L _1350 . Using the SDSS-RM lag sample, we derive improved single-epoch (SE) mass recipes for H β , Mg ii , and C iv , which are consistent with their respective RM masses as well as between the SE recipes from two different lines, over the luminosity range probed by our sample. The new H β and Mg ii recipes are approximately unbiased estimators at given RM masses, but there are systematic biases in the C iv recipe. The intrinsic scatter of SE masses around RM masses is ∼0.45 dex for H β and Mg ii , increasing to ∼0.58 dex for C iv .

We report the discovery of large, ionized, [O ii ]-emitting circumgalactic nebulae around the majority of 30 UV-luminous quasars at z = 0.4–1.4 observed with deep, wide-field integral field spectroscopy with the Multi-Unit Spectroscopy Explorer (MUSE) by the Cosmic Ultraviolet Baryon Survey and MUSE Quasar Blind Emitters Survey. Among the 30 quasars, seven (23%) exhibit [O ii ]-emitting nebulae with major axis sizes greater than 100 kpc, 20 greater than 50 kpc (67%), and 27 (90%) greater than 20 kpc. Such large, optically emitting nebulae indicate that cool, dense, and metal-enriched circumgalactic gas is common in the halos of luminous quasars at intermediate redshift. Several of the largest nebulae exhibit morphologies that suggest interaction-related origins. We detect no correlation between the sizes and cosmological-dimming-corrected surface brightnesses of the nebulae and quasar redshift, luminosity, black hole mass, or radio-loudness, but find a tentative correlation between the nebulae and rest-frame [O ii ] equivalent width in the quasar spectra. This potential trend suggests a relationship between interstellar medium content and gas reservoirs on CGM scales. The [O ii ]-emitting nebulae around the z ≈ 1 quasars are smaller and less common than Ly α nebulae around z ≈ 3 quasars. These smaller sizes can be explained if the outer regions of the Ly α halos arise from scattering in more neutral gas, by evolution in the cool circumgalactic medium content of quasar-host halos, by lower-than-expected metallicities on ≳50 kpc scales around z ≈ 1 quasars, or by changes in quasar episodic lifetimes between z = 3 and 1.

We present the first results from the Revealing Low-Luminosity Active Galactic Nuclei (ReveaLLAGN) survey, a JWST survey of seven nearby LLAGNs. We focus on two observations with the Mid-Infrared Instrument (MIRI)’s Medium-Resolution Spectrometer of the nuclei of NGC 1052 and Sombrero (NGC 4594/M104). We also compare these data to public JWST data of higher-luminosity AGNs, NGC 7319 and NGC 7469. JWST clearly separates the AGN spectrum from the galaxy light even in Sombrero, the faintest target in our survey; the AGN components have very red spectra. We find that the emission-line widths in both NGC 1052 and Sombrero increase with increasing ionization potential, with FWHM > 1000 km s ^−1 for lines with ionization potential ≳ 50 eV. These lines are also significantly blueshifted in both LLAGNs. The high-ionization-potential lines in NGC 7319 show neither broad widths nor significant blueshifts. Many of the lower-ionization-potential emission lines in Sombrero show significant blue wings extending >1000 km s ^−1 . These features and the emission-line maps in both galaxies are consistent with outflows along the jet direction. Sombrero has the lowest-luminosity high-ionization-potential lines ([Ne v ] and [O iv ]) ever measured in the mid-infrared, but the relative strengths of these lines are consistent with higher-luminosity AGNs. On the other hand, the [Ne v ] emission is much weaker relative to the [Ne iii ] and [Ne ii ] lines of higher-luminosity AGNs. These initial results show the great promise that JWST holds for identifying and studying the physical nature of LLAGNs.

Drawing from the Chandra archive and using a carefully selected set of nearby dwarf galaxies, we present a calibrated high-mass X-ray binary (HMXB) luminosity function in the low-mass galaxy regime and search for an already hinted at dependence on metallicity. Our study introduces a new sample of local dwarf galaxies ( D < 12.5 Mpc and M _* < 5 × 10 ^9 M _⊙ ), expanding the specific star formation rates (sSFR) and gas-phase metallicities probed in previous investigations. Our analysis of the observed X-ray luminosity function indicates a shallower power-law slope for the dwarf galaxy HMXB population. In our study, we focus on dwarf galaxies that are more representative in terms of sSFR compared to prior work. In this regime, the HMXB luminosity function exhibits significant stochastic sampling at high luminosities. This likely accounts for the pronounced scatter observed in the galaxy-integrated HMXB population’s L _X /SFR versus metallicity for our galaxy sample. Our calibration is necessary to understand the active galactic nuclei content of low-mass galaxies identified in current and future X-ray survey fields and has implications for binary population synthesis models, as well as X-ray-driven cosmic heating in the early Universe.

We present the result of a spectroscopic campaign targeting active galactic nucleus (AGN) candidates selected using a novel unsupervised machine-learning (ML) algorithm trained on optical and mid-infrared photometry. AGN candidates are chosen without incorporating prior AGN selection criteria and are fainter, redder, and more numerous, ∼340 AGN deg ^−2 , than comparable photometric and spectroscopic samples. In this work, we obtain 178 rest-optical spectra from two candidate ML-identified AGN classes with the Hectospec spectrograph on the MMT Observatory. We find that our first ML-identified group is dominated by Type I AGNs (85%) with a

The James Webb Space Telescope is revealing a new population of dust-reddened broad-line active galactic nuclei (AGN) at redshifts z ≳ 5. Here we present deep NIRSpec/Prism spectroscopy from the Cycle 1 Treasury program Ultradeep NIRSpec and NIRCam ObserVations before the Epoch of Reionization (UNCOVER) of 15 AGN candidates selected to be compact, with red continua in the rest-frame optical but with blue slopes in the UV. From NIRCam photometry alone, they could have been dominated by dusty star formation or an AGN. Here we show that the majority of the compact red sources in UNCOVER are dust-reddened AGN: 60% show definitive evidence for broad-line H α with a FWHM > 2000 km s ^−1 , 20% of the current data are inconclusive, and 20% are brown dwarf stars. We propose an updated photometric criterion to select red z > 5 AGN that excludes brown dwarfs and is expected to yield >80% AGN. Remarkably, among all z _phot > 5 galaxies with F277W – F444W > 1 in UNCOVER at least 33% are AGN regardless of compactness, climbing to at least 80% AGN for sources with F277W – F444W > 1.6. The confirmed AGN have black hole masses of 10 ^7 –10 ^9 M _⊙ . While their UV luminosities (−16 > M _UV > −20 AB mag) are low compared to UV-selected AGN at these epochs, consistent with percent-level scattered AGN light or low levels of unobscured star formation, the inferred bolometric luminosities are typical of 10 ^7 –10 ^9 M _⊙ black holes radiating at ∼10%–40% the Eddington limit. The number densities are surprisingly high at ∼10 ^−5 Mpc ^−3 mag ^−1 , 100 times more common than the faintest UV-selected quasars, while accounting for ∼1% of the UV-selected galaxies. While their UV faintness suggests they may not contribute strongly to reionization, their ubiquity poses challenges to models of black hole growth.

The era of the James Webb Space Telescope ushers stellar population models into uncharted territories, particularly at the high-redshift frontier. In a companion paper, we apply the Prospector Bayesian framework to jointly infer galaxy redshifts and stellar population properties from broadband photometry as part of the UNCOVER survey. Here we present a comprehensive error budget in spectral energy distribution (SED) modeling. Using a sample selected to have photometric redshifts higher than 9, we quantify the systematic shifts stemming from various model choices in inferred stellar mass, star formation rate (SFR), and age. These choices encompass different timescales for changes in the star formation history (SFH), nonuniversal stellar initial mass functions (IMF), and the inclusion of variable nebular abundances, gas density, and ionizing photon budget. We find that the IMF exerts the strongest influence on the inferred properties: the systematic uncertainties can be as much as 1 dex, 2–5 times larger than the formal reported uncertainties in mass and SFR, and importantly, exceed the scatter seen when using different SED fitting codes. Although the assumptions on the lower end of the IMF induce degeneracy, our findings suggest that a common practice in the literature of assessing uncertainties in SED-fitting processes by comparing multiple codes is substantively underestimating the true systematic uncertainty. Highly stochastic SFHs change the inferred SFH by much larger than the formal uncertainties, and introduce ∼0.8 dex systematics in SFR averaged over a short timescale and ∼0.3 dex systematics in average age. Finally, employing a flexible nebular emission model causes ∼0.2 dex systematic increase in mass and SFR, comparable to the formal uncertainty. This paper constitutes an initial step toward a complete uncertainty estimate in SED modeling.

It is exceedingly rare to find quiescent low-mass galaxies in the field at low redshift. UGC 5205 is an example of such a quenched field dwarf ( M _⋆ ∼ 3 × 10 ^8 M _⊙ ). Despite a wealth of cold gas ( M _HI ∼ 3.5 × 10 ^8 M _⊙ ) and UV emission that indicates significant star formation in the past few hundred megayears, there is no detection of H α emission—star formation in the last ∼10 Myr—across the face of the galaxy. Meanwhile, the near equal-mass companion of UGC 5205, PGC 027864, is starbursting (which has an H α equivalent width > 1000 Å). In this work, we present new Karl G. Jansky Very Large Array 21 cm line observations of UGC 5205, showing that the lack of star formation is caused by an absence of H i in the main body of the galaxy. The H i of UGC 5205 is highly disturbed; the bulk of the H i resides in several-kiloparsec–long tails, while the H i of PGC 027864 is dominated by ordered rotation. We model the stellar populations of UGC 5205 to show that, as indicated by the UV and H α emission, the galaxy underwent a coordinated quenching event ∼100–300 Myr ago. The asymmetry of outcomes for UGC 5205 and PGC 027864 demonstrate that major mergers can both quench and trigger star formation in dwarfs. However, because the gas remains bound to the system, we suggest that such mergers only temporarily quench star formation. We estimate a total quenched time of ∼560 Myr for UGC 5205, consistent with established upper limits on the quenched fraction of a few percent for dwarfs in the field.

We report JWST/NIRSpec spectra of three distant T-type brown dwarfs identified in the Ultradeep NIRSpec and NIRCam ObserVations before the Epoch of Reionization (UNCOVER) survey of the Abell 2744 lensing field. One source was previously reported as a candidate T dwarf on the basis of NIRCam photometry, while two sources were initially identified as candidate active galactic nuclei. Low-resolution 1–5 μ m spectra confirm the presence of molecular features consistent with T dwarf atmospheres, and comparison to spectral standards infers classifications of sdT1, T6, and T8–T9. The warmest source, UNCOVER-BD-1, shows evidence of subsolar metallicity, and atmosphere model fits indicate T _eff = 1300 K and [M/H] ∼ −1.0, making this one of the few spectroscopically confirmed T subdwarfs known. The coldest source, UNCOVER-BD-3, is near the T/Y dwarf boundary with T _eff = 550 K, and our analysis indicates the presence of PH _3 in the 3–5 μ m region, favored over CO _2 and a possible indicator of subsolar metallicity. We estimate distances of 0.9–4.5 kpc from the Galactic midplane, making these the most distant brown dwarfs with spectroscopic confirmation. Population simulations indicate high probabilities of membership in the Galactic thick disk for two of these brown dwarfs, and potential halo membership for UNCOVER-BD-1. Our simulations indicate that there are approximately 5 T dwarfs and 1–2 L dwarfs in the Abell 2744 field down to F444W = 30 AB mag, roughly one-third of which are thick disk members. These results highlight the utility of deep JWST/NIRSpec spectroscopy for identifying and characterizing the oldest metal-poor brown dwarfs in the Milky Way.

Quasar-driven galactic outflows are a major driver of the evolution of massive galaxies. We report observations of a powerful galactic-scale outflow in a z = 3 extremely red and intrinsically luminous ( L _bol ≃ 5 × 10 ^47 erg s ^−1 ) quasar SDSSJ1652 + 1728 with the Near-infrared Spectrograph on board JWST. We analyze the kinematics of rest-frame optical emission lines and identify the quasar-driven outflow extending out to ∼10 kpc from the quasar with a velocity offset of ( v _r = ± 500 km s ^−1 ) and high velocity dispersion (FWHM = 700–2400 km s ^−1 ). Due to JWST’s unprecedented surface brightness sensitivity in the near-infrared, we unambiguously show that the powerful high velocity outflow in an extremely red quasar encompasses a large swath of the host galaxy’s interstellar medium. Using the kinematics and dynamics of optical emission lines, we estimate the mass outflow rate—in the warm ionized phase alone—to be at least 2300 ± 1400 M _⊙ yr ^−1 . We measure a momentum flux ratio between the outflow and the quasar accretion disk of ∼1 on a kpc scale, indicating that the outflow was likely driven in a relatively high (>10 ^23 cm ^−2 ) column density environment through radiation pressure on dust grains. We find a coupling efficiency between the bolometric luminosity of the quasar and the outflow of 0.1%, matching the theoretical prediction of the minimum coupling efficiency necessary for negative quasar feedback. The outflow has sufficient energetics to drive the observed turbulence seen in shocked regions of the quasar host galaxy, which are likely directly responsible for prolonging the time that it takes for gas to cool efficiently.