Missing Giants: Predictions on Dust-Obscured Galaxy Stellar Mass Assembly Throughout Cosmic Time

Due to their extremely dust-obscured nature, much uncertainty still exists surrounding the stellar mass growth and content in dusty, star-forming galaxies (DSFGs) at $z>1$. In this work, we present a numerical model built using empirical data on DSFGs to estimate their stellar mass contributions across the first $\sim$10 Gyr of cosmic time. We generate a dust-obscured stellar mass function that extends beyond the mass limit of star-forming stellar mass functions in the literature, and predict that massive DSFGs constitute as much as $50-100\%$ of all star-forming galaxies with M $\ge10^{11}$M$_\odot$ at $z>1$. We predict the number density of massive DSFGs and find general agreement with observations, although more data is needed to narrow wide observational uncertainties. We forward model mock massive DSFGs to their quiescent descendants and find remarkable agreement with observations from the literature demonstrating that, to first order, massive DSFGs are a sufficient ancestral population to describe the prevalence of massive quiescent galaxies at $z>1$. We predict that massive DSFGs and their descendants contribute as much as $25-60\%$ to the cosmic stellar mass density during the peak of cosmic star formation, and predict an intense epoch of population growth during the $\sim1$ Gyr from $z=6$ to 3 during which the majority of the most massive galaxies at high-$z$ grow and then quench. Future studies seeking to understand massive galaxy growth and evolution in the early Universe should strategize synergies with data from the latest observatories (e.g. JWST and ALMA) to better include the heavily dust-obscured galaxy population.Comment: 22 pages, 9 figures, submitted to Ap

Clinical Skills Development in the Virtual Learning Environment: Adapting to a New World

The rapid transition to distance learning in response to the unexpected SARS-CoV-2/COVID-19 pandemic led to disruption of clinical skills development, which are typically conducted face-to-face. Consequently, faculty adapted their courses, using a multitude of active learning modalities, to meet student learning objectives in the didactic and experiential settings. Strategies and considerations to implement innovative delivery methods and address potential challenges are elucidated. Furthermore, integration of a layered learning approach may allow for more broad perspectives and allow additional interactions and feedback, which is especially necessary in the virtual environment.https://digitalcommons.chapman.edu/pharmacy_books/1025/thumbnail.jp

JWST and ALMA discern the assembly of structural and obscured components in a high-redshift starburst galaxy

We present observations and analysis of the starburst, PACS-819, at z=1.45 ($M_*=10^{10.7}$ M$_{ \odot}$), using high-resolution ($0^{\prime \prime}.1$; 0.8 kpc) ALMA and multi-wavelength JWST images from the COSMOS-Web program. Dissimilar to HST/ACS images in the rest-frame UV, the redder NIRCam and MIRI images reveal a smooth central mass concentration and spiral-like features, atypical for such an intense starburst. Through dynamical modeling of the CO J=5--4 emission with ALMA, PACS-819 is rotation-dominated thus has a disk-like nature. However, kinematic anomalies in CO and asymmetric features in the bluer JWST bands (e.g., F150W) support a more disturbed nature likely due to interactions. The JWST imaging further enables us to map the distribution of stellar mass and dust attenuation, thus clarifying the relationships between different structural components, not discernable in the previous HST images. The CO J = 5 -- 4 and FIR dust continuum emission are co-spatial with a heavily-obscured starbursting core (<1 kpc) which is partially surrounded by much less obscured star-forming structures including a prominent arc, possibly a tidally-distorted dwarf galaxy, and a clump, either a sign of an ongoing violent disk instability or a recently accreted low-mass satellite. With spatially-resolved maps, we find a high molecular gas fraction in the central area reaching $\sim3$ ($M_{\text{gas}}$/$M_*$) and short depletion times ($M_{\text{gas}}/SFR\sim$ 120 Myrs) across the entire system. These observations provide insights into the complex nature of starbursts in the distant universe and underscore the wealth of complementary information from high-resolution observations with both ALMA and JWST.Comment: 18 pages, 12 figures, Submitted to Ap

Uncovering a Massive z~7.65 Galaxy Hosting a Heavily Obscured Radio-Loud QSO Candidate in COSMOS-Web

In this letter, we report the discovery of the highest redshift, heavily obscured, radio-loud QSO candidate selected using JWST NIRCam/MIRI, mid-IR, sub-mm, and radio imaging in the COSMOS-Web field. Using multi-frequency radio observations and mid-IR photometry, we identify a powerful, radio-loud (RL), growing supermassive black hole (SMBH) with significant spectral steepening of the radio SED ($f_{1.32 \mathrm{GHz}} \sim 2$ mJy, $q_{24\mu m} = -1.1$, $\alpha_{1.32-3\mathrm{GHz}}=-1.2$, $\Delta \alpha = -0.4$). In conjunction with ALMA, deep ground-based observations, ancillary space-based data, and the unprecedented resolution and sensitivity of JWST, we find no evidence of QSO contribution to the UV/optical/NIR data and thus infer heavy amounts of obscuration (N$_{\mathrm{H}} > 10^{23}$ cm$^{-2}$). Using the wealth of deep UV to sub-mm photometric data, we report a singular solution photo-z of $z_\mathrm{phot}$ = 7.65$^{+0.4}_{-0.3}$ and estimate an extremely massive host-galaxy ($\log M_{\star} = 11.92 \pm 0.06\,\mathrm{M}_{\odot}$). This source represents the furthest known obscured RL QSO candidate, and its level of obscuration aligns with the most representative but observationally scarce population of QSOs at these epochs.Comment: Submitted to ApJL, Comments welcom

Comparison between dynamic [18F]Fluoroethyltyrosine PET/CT and advanced MRI in cerebral high and low grade gliomas.\ua0 ;\ua0

Comparison between dynamic [18F]Fluoroethyltyrosine PET/CT and advanced MRI in cerebral high and low grade gliomas L. Picori, U. Rozzanigo, D. Donner, M. Erini, P. Feraco, M. Recla, F. Chierichetti; Santa Chiara Hospital, Trento, ITALY. Aim/Introduction: To investigate if dynamic [18F]fluoroethyl- L-tyrosine [18F]FET PET/CT improves the diagnosis in patients with suspected new or recurrent cerebral gliomas, respect to advanced MRI techniques. Materials and Methods: We retrospectively evaluated 20 patients who performed [18F] FET by a PET/CT tomograph: 15 had an indeterminate brain lesion, 5 a suspect glioma recurrence. All patients underwent a 40 minutes dynamic [18F]FET PET/CT acquisition and two different sequences, between 5-15 minutes and 20-30 minutes. For dynamic studies time-activity and time to peak curves were extracted using different region-of-interest (ROIs) and volume of interest (VOIs) definitions. MRI was performed with a 1.5T scanner just before [18F]FET-PET/CT using perfusion (PWI) and diffusion (DWI) weighted imaging: afterwards rCBV and ADC values were calculated placing the VOIs on the solid components of the lesion. In case of doubt (13 cases) single-voxel MR spectroscopy was performed. Multimodality imaging by fusion of PET/CT and different MRI sequences was performed for a joint assessment (radiologist and nuclear physician). Results: Final diagnosis was based on histology in 8 patients who underwent neurosurgery (5 HGG, 3 LGG) and on follow-up imaging in 12 patients (8 tumor progression, 4 stable benign lesion). On the basis of [18F]FET- PET, 7 cases were classified as high uptake (2 glioma recurrence and 5 new diagnosis of HGG tumor), 8 as low uptake (4 glioma recurrence, 2 new diagnosis of LGG tumor, 1 tumor progression, 1 tumefactive demielinating lesion) and 5 as no uptake (1 new diagnosis of LGG tumor, 4 stable benign lesion). Sensibility for dynamic [18F]FET-PET was 93% and specificity was 80%. Multiparametric MRI was in agreement with [18F]FET-PET in all 7 cases of high uptake and in 5 cases of low uptake. [18F]FET- PET helped to classify 6 MRI indeterminate lesions (2 suspect radionecrosis with pathologic uptake, 4 benign lesions without uptake). In 2 cases there was a discrepancy between MRI and PET: 1 tumefactive demielinating lesion was classified by [18F] FET as low uptake lesion, 1 LGG confirmed at histology showed no uptake. Conclusion: In our experience, adding quantitative data, such as dynamic acquisition in PET/CT by aminoacid tracer like [18F]FET, to rCBV and ADC maps in advanced MRI is crucial for a better comprehension of tumor lesions and to assess grading. Dynamic [18F]FET-PET/CT and multiparametric MR imaging have a very high sensibility to detect new tumoral lesions or suspect glioma recurrence. Agreement between PET and MRI is essential to improve diagnostic specificity. References: None