339 research outputs found

    Early JWST imaging reveals strong optical and NIR color gradients in galaxies at z2z\sim2 driven mostly by dust

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    Recent studies have shown that galaxies at cosmic noon are redder in the center and bluer in the outskirts, mirroring results in the local universe. These color gradients could be caused by either gradients in the stellar age or dust opacity; however, distinguishing between these two causes is impossible with rest-frame optical photometry alone. Here we investigate the underlying causes of the gradients from spatially-resolved rest-frame UVU-V vs. VJV-J color-color diagrams, measured from early observations with the James Webb Space Telescope. We use 1μm4μm1\, \mu m - 4\, \mu m NIRCam photometry from the CEERS survey of a sample of 54 galaxies with M/M>10M_* / M_\odot>10 at redshifts 1.7<z<2.31.7<z<2.3 selected from the 3D-HST catalog. We model the light profiles in the F115W, F200W and F356W NIRCam bands using \texttt{imcascade}, a Bayesian implementation of the Multi-Gaussian expansion (MGE) technique which flexibly represents galaxy profiles using a series of Gaussians. We construct resolved rest-frame UVU-V and VJV-J color profiles. The majority of star-forming galaxies have negative gradients (i.e. redder in the center, bluer in the outskirts) in both UVU-V and VJV-J colors consistent with radially decreasing dust attenuation. A smaller population (roughly 15\%) of star-forming galaxies have positive UVU-V but negative VJV-J gradients implying centrally concentrated star-formation. For quiescent galaxies we find a diversity of UVJ color profiles, with roughly one-third showing star-formation in their center. This study showcases the potential of JWST to study the resolved stellar populations of galaxies at cosmic noon.Comment: Updated to match published version, new Figure 5 and some text change

    Rest-frame near-infrared sizes of galaxies at cosmic noon: objects in JWST's mirror are smaller than they appeared

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    Galaxy sizes and their evolution over cosmic time have been studied for decades and serve as key tests of galaxy formation models. However, at z1z\gtrsim1 these studies have been limited by a lack of deep, high-resolution rest-frame infrared imaging that accurately traces galaxy stellar mass distributions. Here, we leverage the new capabilities of the James Webb Space Telescope to measure the 4.4μ\mum sizes of 1000{\sim}1000 galaxies with logM/M9\log{\rm{M}_*/\rm{M}_\odot}\ge9 and 1.0z2.51.0\le z \le 2.5 from public CEERS imaging in the EGS deep field. We compare the sizes of galaxies measured from NIRCam imaging at 4.4μ\mum (λrest1.6μ\lambda_{\mathrm{rest}}\sim1.6\mu m) with sizes measured at 1.5μ1.5\mum (λrest5500\lambda_{\mathrm{rest}}\sim5500A). We find that, on average, galaxy half-light radii are 8\sim8% smaller at 4.4μ\mum than 1.5μ\mum in this sample. This size difference is markedly stronger at higher stellar masses and redder rest-frame VJV-J colors: galaxies with M1011M{\rm M}_* \sim 10^{11}\,{\rm M}_\odot have 4.4μ\mum sizes that are 25\sim 25% smaller than their 1.5μ\mum sizes. Our results indicate that galaxy mass profiles are significantly more compact than their rest-frame optical light profiles at cosmic noon, and demonstrate that spatial variations in age and attenuation are important, particularly for massive galaxies. The trend that we find here impacts our understanding of the size growth and evolution of galaxies, and suggests that previous studies based on rest-frame optical light may not have captured the mass-weighted structural evolution of galaxies. This paper represents a first step towards a new understanding of the morphologies of early massive galaxies enabled by JWST's infrared window into the distant universe.Comment: Accepted to ApJL. 10 pages, 4 figures, 1 table with full size catalog in F150W and F444

    Dual Action of miR-125b As a Tumor Suppressor and OncomiR-22 Promotes Prostate Cancer Tumorigenesis

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    MicroRNAs (miRs) are a novel class of small RNA molecules, the dysregulation of which can contribute to cancer. A combinatorial approach was used to identify miRs that promote prostate cancer progression in a unique set of prostate cancer cell lines, which originate from the parental p69 cell line and extend to a highly tumorigenic/metastatic M12 subline. Together, these cell lines are thought to mimic prostate cancer progression in vivo. Previous network analysis and miR arrays suggested that the loss of hsa-miR-125b together with the overexpression of hsa-miR-22 could contribute to prostate tumorigenesis. The dysregulation of these two miRs was confirmed in human prostate tumor samples as compared to adjacent benign glandular epithelium collected through laser capture microdissection from radical prostatectomies. In fact, alterations in hsa-miR-125b expression appeared to be an early event in tumorigenesis. Reverse phase microarray proteomic analysis revealed ErbB2/3 and downstream members of the PI3K/AKT and MAPK/ERK pathways as well as PTEN to be protein targets differentially expressed in the M12 tumor cell compared to its parental p69 cell. Relevant luciferase+3’-UTR expression studies confirmed a direct interaction between hsa-miR-125b and ErbB2 and between hsa-miR-22 and PTEN. Restoration of hsa-miR-125b or inhibition of hsa-miR-22 expression via an antagomiR resulted in an alteration of M12 tumor cell behavior in vitro. Thus, the dual action of hsa-miR-125b as a tumor suppressor and hsa-miR-22 as an oncomiR contributed to prostate tumorigenesis by modulations in PI3K/AKT and MAPK/ERK signaling pathways, key pathways known to influence prostate cancer progression

    Quantifying the Effects of Known Unknowns on Inferred High-redshift Galaxy Properties: Burstiness, the IMF, and Nebular Physics

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    The era of the James Webb Space Telescope ushers stellar populations models into uncharted territories, particularly at the high-redshift frontier. In a companion paper, we apply the \texttt{Prospector} Bayesian framework to jointly infer galaxy redshifts and stellar populations properties from broad-band photometry as part of the UNCOVER survey. Here we present a comprehensive error budget in spectral energy distribution (SED) modeling. Using a zphot>9z_{\rm phot}>9 sample, 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), non-universal 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. This means 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\sim 0.8 dex systematics in SFR and 0.3\sim 0.3 dex systematics in average age. Finally, employing a flexible nebular emission model causes 0.2\sim 0.2 dex systematic increase in mass, comparable to the formal uncertainty. This paper constitutes one of the initial steps toward a complete uncertainty estimate in SED modeling.Comment: Submitted to ApJ. 18 pages, 8 figures, 2 table

    "Now he walks and walks, as if he didn't have a home where he could eat": food, healing, and hunger in Quechua narratives of madness

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    In the Quechua-speaking peasant communities of southern Peru, mental disorder is understood less as individualized pathology and more as a disturbance in family and social relationships. For many Andeans, food and feeding are ontologically fundamental to such relationships. This paper uses data from interviews and participant observation in a rural province of Cuzco to explore the significance of food and hunger in local discussions of madness. Carers’ narratives, explanatory models, and theories of healing all draw heavily from idioms of food sharing and consumption in making sense of affliction, and these concepts structure understandings of madness that differ significantly from those assumed by formal mental health services. Greater awareness of the salience of these themes could strengthen the input of psychiatric and psychological care with this population and enhance knowledge of the alternative treatments that they use. Moreover, this case provides lessons for the global mental health movement on the importance of openness to the ways in which indigenous cultures may construct health, madness, and sociality. Such local meanings should be considered by mental health workers delivering services in order to provide care that can adjust to the alternative ontologies of sufferers and carers

    Two Remarkably Luminous Galaxy Candidates at z1113z\approx11-13 Revealed by JWST

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    The first few hundred Myrs at z>10z>10 mark the last major uncharted epoch in the history of the Universe, where only a single galaxy (GNz11 at z11z\approx11) is currently spectroscopically confirmed. Here we present a search for luminous z>10z>10 galaxies with JWSTJWST/NIRCam photometry spanning 15μ\approx1-5\mum and covering 49 arcmin2^{2} from the public JWSTJWST Early Release Science programs (CEERS and GLASS). Our most secure candidates are two MUV21M_{\rm{UV}}\approx-21 systems: GLASS-z13 and GLASS-z11. These galaxies display abrupt 2.5\gtrsim2.5 mag breaks in their spectral energy distributions, consistent with complete absorption of flux bluewards of Lyman-α\alpha that is redshifted to z13z\approx13 and z11z\approx11. Lower redshift interlopers such as dusty quiescent galaxies with strong Balmer breaks would be comfortably detected at >5σ>5\sigma in multiple bands where instead we find no flux. From SED modeling we infer that these galaxies have already built up 109\sim 10^9 solar masses in stars over the 300400\lesssim300-400 Myrs after the Big Bang. The brightness of these sources enable morphological constraints. Tantalizingly, GLASS-z11 shows a clearly extended exponential light profile, potentially consistent with a disk galaxy of r500.7r_{\rm{50}}\approx0.7 kpc. These sources, if confirmed, join GNz11 in defying number density forecasts for luminous galaxies based on Schechter UV luminosity functions, which require a survey area >10×>10\times larger than we have studied here to find such luminous sources at such high redshifts. They extend evidence from lower redshifts for little or no evolution in the bright end of the UV luminosity function into the cosmic dawn epoch, with implications for just how early these galaxies began forming. This, in turn, suggests that future deep JWSTJWST observations may identify relatively bright galaxies to much earlier epochs than might have been anticipated.Comment: Submitted to ApJL. Figs. 1 and 2 summarize the candidates, Fig. 3 places the brightness of these systems in context, Fig. 4 shows the morphology, Fig. 5 explores implications for the UVLF. Comments warmly welcome

    JWST reveals a population of ultra-red, flattened disk galaxies at 2<z<6 previously missed by HST

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    With just a month of data, JWST is already transforming our view of the Universe, revealing and resolving starlight in unprecedented populations of galaxies. Although ``HST-dark" galaxies have previously been detected at long wavelengths, these observations generally suffer from a lack of spatial resolution which limits our ability to characterize their sizes and morphologies. Here we report on a first view of starlight from a subset of the HST-dark population that are bright with JWST/NIRCam (4.4μ\mum<24.5mag) and very faint or even invisible with HST (<<1.6μ\mum). In this Letter we focus on a dramatic and unanticipated population of physically extended galaxies (\gtrsim0.17''). These 12 galaxies have photometric redshifts 2<z<62<z<6, high stellar masses M1010 MM_{\star}\gtrsim 10^{10}~M_{\odot}, and significant dust-attenuated star formation. Surprisingly, the galaxies have elongated projected axis ratios at 4.4μ\mum, suggesting that the population is disk-dominated or prolate. Most of the galaxies appear red at all radii, suggesting significant dust attenuation throughout. We refer to these red, disky, HST-dark galaxies as Ultra-red Flattened Objects (UFOs). With rer_e(F444W)12\sim1-2~kpc, the galaxies are similar in size to compact massive galaxies at z2z\sim2 and the cores of massive galaxies and S0s at z0z\sim0. The stellar masses, sizes, and morphologies of the sample suggest that some could be progenitors of lenticular or fast-rotating galaxies in the local Universe. The existence of this population suggests that our previous censuses of the universe may have missed massive, dusty edge-on disks, in addition to dust-obscured starbursts

    The Benefits and Burdens of Pediatric Palliative Care and End-of-Life Research: A Systematic Review

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    Objective: The aim of this study is to report the benefits and burdens of palliative research participation on children, siblings, parents, clinicians, and researchers. Background: Pediatric palliative care requires research to mature the science and improve interventions. A tension exists between the desire to enhance palliative and end-of-life care for children and their families and the need to protect these potentially vulnerable populations from untoward burdens. Methods: Systematic review followed PRISMA guidelines with prepared protocol registered as PROSPERO #CRD42018087304. MEDLINE, CINAHL, PsycINFO, EMBASE, Scopus, and The Cochrane Library were searched (2000–2017). English-language studies depicting the benefits or burdens of palliative care or end-of-life research participation on either pediatric patients and/or their family members, clinicians, or study teams were eligible for inclusion. Study quality was appraised using the Mixed Methods Appraisal Tool (MMAT). Results: Twenty-four studies met final inclusion criteria. The benefit or burden of palliative care research participation was reported for the child in 6 papers; siblings in 2; parents in 19; clinicians in 3; and researchers in 5 papers. Benefits were more heavily emphasized by patients and family members, whereas burdens were more prominently emphasized by researchers and clinicians. No paper utilized a validated benefit/burden scale. Discussion: The lack of published exploration into the benefits and burdens of those asked to take part in pediatric palliative care research and those conducting the research is striking. There is a need for implementation of a validated benefit/burden instrument or interview measure as part of pediatric palliative and end-of-life research design and reporting
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