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X-Ray Imaging and Spectroscopy Mission
No full textThe X-Ray Imaging and Spectroscopy Mission (XRISM) is a joint mission between the Japan Aerospace Exploration Agency (JAXA) and the National Aeronautics and Space Administration (NASA) in collaboration with the European Space Agency (ESA). In addition to the three space agencies, universities and research institutes from Japan, North America, and Europe have joined to contribute to developing satellite and onboard instruments, data-processing software, and the scientific observation program. XRISM is the successor to the ASTRO-H (Hitomi) mission, which ended prematurely in 2016. Its primary science goal is to examine astrophysical problems with precise, high-resolution X-ray spectroscopy. XRISM promises to discover new horizons in X-ray astronomy. It carries a 6 × 6 pixelized X-ray microcalorimeter on the focal plane of an X-ray mirror assembly (Resolve) and a co-aligned X-ray CCD camera (Xtend) that covers the same energy band over a large field of view. XRISM utilizes the Hitomi heritage, but all designs were reviewed. The attitude and orbit control system was improved in hardware and software. The spacecraft was launched from the JAXA Tanegashima Space Center on 2023 September 6 (UTC). During the in-orbit commissioning phase, the onboard components were activated. Although the gate valve protecting the Resolve sensor with a thin beryllium X-ray entrance window was not yet opened, scientific observation started in 2024 February with the planned performance verification observation program. The nominal observation program commenced with the following guest observation program beginning in 2024 September.Our science activity was partly supported by the JSPS Core-to-Core Program (grant number:
JPJSCCA20220002).https://academic.oup.com/pasj/advance-article/doi/10.1093/pasj/psaf023/811146
How to Do Accompaniment
No full textThis essay examines the integration of accompaniment methodology with public humanities and policy work through case studies from activist research in New Orleans. The concept of accompaniment involves providing active, supportive engagement alongside marginalized communities to address systemic barriers and foster mutual understandings. This essay highlights how accompaniment can provide support in navigating bureaucratic challenges and inform immigration policy. It also explores how accompaniment can inform public humanities work, like the development of a digital timeline and physical exhibition documenting Black labor history in New Orleans. This approach underscores the transformative potential of combining accompaniment with public humanities to enhance community empowerment, inform policy, and challenge systemic inequities. By engaging with community experiences and integrating insights from both historical and contemporary struggles, this essay chronicles the development of accompaniment methodology and shows how this approach can enrich public humanities scholarship and policy work, creating more inclusive and responsive solutions to social challenges. Accompaniment serves as a vital tool for bridging academic inquiry with social justice, making public humanities research more relevant, ethical, equitable, and impactful.https://www.cambridge.org/core/journals/public-humanities/article/how-to-do-accompaniment/5F3107EEDEFB81A860789F241B2AEEF
The Pandora SmallSat: A Low-Cost, High Impact Mission to Study Exoplanets and Their Host Stars
No full textIEEE Aerospace Conference 2025The Pandora SmallSat is a NASA flight project aimed at studying the atmospheres of exoplanets -- planets orbiting stars outside our Solar System. Pandora will provide the first dataset of simultaneous, multiband (visible and NIR), long-baseline observations of exoplanets and their host stars. Pandora is an ambitious project that will fly a 0.44 m telescope in a small form factor. To achieve the scientific goals, the mission requires a departure from the traditional cost-schedule paradigm of half-meter-class observatories. Pandora achieves this by leveraging existing capabilities that necessitate minimal engineering development, disruptive and agile management, trusted partnerships with vendors, and strong support from the lead institutions. The Pandora team has developed a suite of high-fidelity parameterized simulation and modeling tools to estimate the performance of both imaging channels. This has enabled a unique bottom-up approach to deriving trades and system requirements. Pandora is a partnership between NASA and Lawrence Livermore National Laboratory. The project completed its Critical Design Review in October 2023 and is slated for launch into Sun-synchronous, low-Earth orbit in Fall 2025.Pandora is supported by NASA’s Astrophysics Pioneers Program. The Pandora team is grateful to the Small Satellite and Special Projects Office at Wallops Flight Facility/Goddard Space Flight Center and the Small Spacecraft Systems Virtual Institute (S3VI) for providing support and resources that have been critical to Pandora’s success. The authors also thank Bruce Yost, Roland Vanderspek, Bernard Rauscher, and many others who contributed to Pandora reviews that improved many facets of the mission.http://arxiv.org/abs/2502.0973
Pathogenicity and phylogeny of Labyrinthula spp. isolated in Washington and Oregon, USA
No full textThe class Labyrinthulomycetes constitutes a multitude of species found ubiquitously in the environment, and includes pathogens of corals, hard clams, turfgrasses, and seagrasses. Labyrinthula zosterae, the causative agent of seagrass wasting disease, has been associated with declines in seagrass coverage since the 1930s. However, pathogenic and nonpathogenic Labyrinthula spp. have been isolated from seagrass tissue. These isolates are difficult to distinguish morphologically, and the diversity of isolates where seagrass wasting disease is present is often unknown. This study aimed to increase knowledge on the pathogenicity and phylogeny of Labyrinthula spp. in Washington and Oregon, USA where a high prevalence of seagrass wasting disease has been associated with eelgrass, Zostera marina, declines. We tested the pathogenicity of 14 Labyrinthula isolates and compared partial 18S rRNA gene sequences of 12 isolates to sequences from around the world through the NCBI database. We found that pathogenic isolates could be identified as Labyrinthula zosterae, while nonpathogenic isolates did not form a clade with any previously identified SSU ribotypes. These results add to the growing data on Labyrinthula and seagrass wasting disease and can improve our understanding of pathogen evolution and spread in the future.Washington Sea Grant, University ofWashington, Grant/Award Number:NA18OAR4170095https://onlinelibrary.wiley.com/doi/abs/10.1111/jeu.1307
I Hate the News Mar 18
No full textThe weekly news analysis from I Hate Politics: Maryland, Virginia, and DC find themselves in different places with their budget and economic woes. Developers ask for deregulation to bring construction activity back to the city. Montgomery County releases 2026 budget proposal that includes property tax and fee hikes. In New Market, MD, the town council passes mayoral term limits in an explosive meeting where opponents say the council violated charter amendment process. Music by Washington DC area composer Anna Rubin.https://open.spotify.com/episode/31s2U94QqkmOSO4QvSxd6
A Measurement of the Largest-Scale CMB E-mode Polarization with CLASS
No full textWe present measurements of large-scale cosmic microwave background (CMB) E-mode polarization from the Cosmology Large Angular Scale Surveyor (CLASS) 90 GHz data. Using 115 det-yr of observations collected through 2024 with a variable-delay polarization modulator, we achieved a polarization sensitivity of 78 µK arcmin, comparable to Planck at similar frequencies (100 and 143 GHz). The analysis demonstrates effective mitigation of systematic errors and addresses challenges to large-angular-scale power recovery posed by time-domain filtering in maximum-likelihood map-making. A novel implementation of the pixel-space transfer matrix is introduced, which enables efficient filtering simulations and bias correction in the power spectrum using the quadratic cross-spectrum estimator. Overall, we achieved an unbiased time-domain filtering correction to recover the largest angular scale polarization, with the only power deficit, arising from map-making non-linearity, being characterized as less than 3%. Through cross-correlation with Planck, we detected the cosmic reionization at 99.4% significance and measured the reionization optical depth τ = 0.053⁺⁰˙⁰¹⁸₋₀.₀₁₉, marking the first ground-based attempt at such a measurement. At intermediate angular scales (ℓ>30), our results, both independently and in cross-correlation with Planck, remain fully consistent with Planck's measurements.Y.L. is supported by the Kavli Institute for Cosmological Physics at the University of Chicago through an endowment from the Kavli Foundation. R. Dünner thanks ANID for grants BASAL CATA FB210003, FONDEF ID21I10236, and QUIMAL240004. Z.X. was supported by the Gordon and Betty Moore Foundation through grant GBMF5215 to the Massachusetts Institute of Technology. We acknowledge the National Science Foundation Division of Astronomical Sciences for their support of CLASS under grant Nos. 0959349, 1429236, 1636634, 1654494, 2034400, and 2109311. We thank Johns Hopkins University President R. Daniels and Dean C. Celenza for their steadfast support of CLASS. We further acknowledge the very generous support of Jim Murren and Heather Miller (JHU A&S ’88), Matthew Polk (JHU A&S Physics BS ’71), David Nicholson, and Michael Bloomberg (JHU Engineering ’64). The CLASS project employs detector technology developed in collaboration between JHU and Goddard Space Flight Center under several previous and ongoing NASA grants. Detector development work at JHU was funded by NASA cooperative agreement 80NSSC19M0005.http://arxiv.org/abs/2501.1190
Looking at Infrared Background Radiation Anisotropies with Spitzer: Large-scale Anisotropies and Their Implications
No full textWe use Spitzer/IRAC deep-exposure data covering two significantly larger than before sky areas to construct maps suitable for evaluating source-subtracted fluctuations in the cosmic infrared background (CIB). The maps are constructed using the self-calibration methodology eliminating artifacts to sufficient accuracy, and subset maps are selected in each area containing approximately uniform exposures. These maps are clipped and removed of known sources and then Fourier transformed to probe the CIB anisotropies to new larger scales. The power spectrum of the resultant CIB anisotropies is measured from the data to >1°, revealing the component well above that from remaining known galaxies on scales >1'. The fluctuations are demonstrated to be free of Galactic and solar system foreground contributions out to the largest scales measured. We discuss the proposed theories for the origin of the excess CIB anisotropies in light of the new data. Out of these, the model where the CIB fluctuation excess originates from the granulation power due to LIGO-observed primordial black holes as dark matter appears most successful in accounting for all observations related to the measured CIB power amplitude and spatial structure, including the measured coherence between the CIB and unresolved cosmic X-ray background (CXB). Finally we point out the use of the data to probe the CIB-CXB cross power to new scales and higher accuracy. We also discuss the synergy of these data with future CIB programs at shorter near-IR wavelengths with deep wide surveys and subarcsecond angular resolution as provided by Euclid and Roman space missions.Work by A.K. and R.G.A. was supported by NASA under award number 80GSFC24M0006. The authors acknowledge support from NASA award 80NSSC22K0621 "Precision measurement of source-subtracted cosmic infrared background from new Spitzer data." This work is based on observations made with the Spitzer Space Telescope, which was operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. We thank Kari Helgason for the software for the LIBRAE project (https://euclid.caltech. edu/page/kashlinsky-team) to reproduce CIB anisotropies from known galaxy populations.https://iopscience.iop.org/article/10.3847/2041-8213/adad5
Invariance-embedded Machine Learning Sub-grid-scale Stress Models for Meso-scale Hurricane Boundary Layer Flow Simulation I: Model Development and a priori Studies
No full textThis study develops invariance-embedded machine learning sub-grid-scale (SGS) stress models admitting turbulence kinetic energy (TKE) backscatter towards more accurate large eddy simulation (LES) of meso-scale turbulent hurricane boundary layer flows. The new machine learning SGS model consists of two parts: a classification model used to distinguish regions with either strong energy cascade or energy backscatter from those with mild TKE transfer and a regression model used to calculate SGS stresses in regions with strong TKE transfer. To ease model implementation in computational fluid dynamics (CFD) solvers, the Smagorinsky model with a signed coefficient Cₛ, where a positive value indicates energy cascade while a negative one indicates energy backscatter, is employed as the carrier of the machine learning model. To improve its robustness and generality, both physical invariance and geometric invariance features of turbulent flows are embedded into the model input for classification and regression, and the signed Smagorinsky model coefficient is used as the output of the regression model. Different machine-learning methods and input setups have been used to test the classification model's performance. The F1-scores, which measure balanced precision and recall of a model, of the classification models with physical and geometric invariance embedded can be improved by about 17% over those without considering geometric invariance. Regression models based on ensemble neural networks have demonstrated superior performance in predicting the signed Smagorinsky model coefficient, exceeding that of the dynamic Smagorinsky model in tests.http://arxiv.org/abs/2504.1447
The bulk motion of gas in the core of the Centaurus galaxy cluster
No full textGalaxy clusters contain vast amounts of hot ionized gas known as the intracluster medium (ICM). In relaxed cluster cores, the radiative cooling time of the ICM is shorter than the age of the cluster. However, the absence of line emission associated with cooling suggests heating mechanisms that offset the cooling, with feedback from active galactic nuclei (AGNs) being the most likely source1,2. Turbulence and bulk motions, such as the oscillating (‘sloshing’) motion of the core gas in the cluster potential well, have also been proposed as mechanisms for heat distribution from the outside of the core3,4. Here we present X-ray spectroscopic observations of the Centaurus galaxy cluster with the X-Ray Imaging and Spectroscopy Mission satellite. We find that the hot gas flows along the line of sight relative to the central galaxy, with velocities from 130 km s⁻¹ to 310 km s⁻¹ within about 30 kpc of the centre. This indicates bulk flow consistent with core gas sloshing. Although the bulk flow may prevent excessive accumulation of cooled gas at the centre, it could distribute the heat injected by the AGN and bring in thermal energy from the surrounding ICM. The velocity dispersion of the gas is found to be only ≲120 km s⁻¹ in the core, even within about 10 kpc of the AGN. This suggests that the influence of the AGN on the surrounding ICM motion is limited in the cluster.This work was supported by JSPS KAKENHI (grant nos JP22H00158, JP22H01268, JP22K03624, JP23H04899, JP21K13963, JP24K00638, JP24K17105, JP21K13958, JP21H01095, JP23K20850, JP24H00253, JP21K03615, JP24K00677, JP20K14491, JP23H00151, JP19K21884, JP20H01947, JP20KK0071, JP23K20239, JP24K00672, JP24K17104, JP24K17093, JP20K04009, JP21H04493, JP20H01946, JP23K13154, JP19K14762, JP20H05857 and JP23K03459) and NASA (grant nos 80NSSC23K0650, 80NSSC20K0733, 80NSSC18K0978, 80NSSC20K0883, 80NSSC20K0737, 80NSSC24K0678, 80NSSC18K1684 and 80NNSC22K1922). L.C. acknowledges support from NSF award 2205918. C.D. acknowledges support from STFC through grant ST/T000244/1 and a Leverhulme International Fellowship IF-2024-020. L. Gallo acknowledges financial support from the Canadian Space Agency grant 18XARMSTMA. A.T. and the present research are in part supported by the Kagoshima University postdoctoral research program (KU-DREAM). S. Yamada acknowledges support from the RIKEN SPDR Program. I.Z. acknowledges partial support from the Alfred P. Sloan Foundation through the Sloan Research Fellowship. M. Sawada acknowledges the support from the RIKEN Pioneering Project Evolution of Matter in the Universe (r-EMU) and the Rikkyo University Special Fund for Research (Rikkyo SFR). N.W. and T.P. acknowledge the financial support of the GAČR EXPRO (grant no. 21-13491X). Part of this work was performed under the auspices of the US Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344. The material is based on the work supported by NASA under award no. 80GSFC21M0002. This work was supported by the JSPS Core-to-Core Program (JPJSCCA20220002). The material is based on the work supported by the Strategic Research Center of Saitama University.https://www.nature.com/articles/s41586-024-08561-
Evaluating spectral cloud effective radius retrievals from the Enhanced MODIS Airborne Simulator (eMAS) during ORACLES
No full textSatellite remote sensing retrievals of cloud effective radius (CER) are widely used for studies of aerosol–cloud interactions. Such retrievals, however, rely on forward radiative transfer (RT) calculations using simplified assumptions that can lead to retrieval errors when the real atmosphere deviates from the forward model. Here, coincident airborne remote sensing and in situ observations obtained during NASA's ObseRvations of Aerosols above CLouds and their intEractionS (ORACLES) field campaign are used to evaluate retrievals of CER for marine boundary layer stratocumulus clouds and to explore impacts of forward RT model assumptions and other confounding factors. Specifically, spectral CER retrievals from the Enhanced MODIS Airborne Simulator (eMAS) and the Research Scanning Polarimeter (RSP) are compared with polarimetric retrievals from RSP and with CER derived from droplet size distributions (DSDs) observed by the Phase Doppler Interferometer (PDI) and a combination of the Cloud and Aerosol Spectrometer (CAS) and the Two-Dimensional Stereo Probe (2D-S). The sensitivities of the eMAS and RSP spectral retrievals to assumptions about the DSD effective variance (CEV) and liquid water complex index of refraction are explored. CER and CEV inferred from eMAS spectral reflectance observations of the backscatter glory provide additional context for the spectral CER retrievals. The spectral and polarimetric CER retrieval agreement is case dependent, and updating the retrieval RT assumptions, including using RSP polarimetric CEV retrievals as a constraint, yields mixed results that are tied to differing sensitivities to vertical heterogeneity. Moreover, the in situ cloud probes, often used as the benchmark for remote sensing CER retrieval assessments, themselves do not agree, with PDI DSDs yielding CER values 1.3–1.6 µm larger than CAS and with CEV roughly 50 %–60 % smaller than CAS. Implications for the interpretation of spectral and polarimetric CER retrievals and their agreement are discussed.This research has been supported by the National Aeronautics and Space Administration Earth Venture Suborbital program (grant no. NNH13ZDA001N-EVS2) and the Radiation Sciences Programhttps://amt.copernicus.org/articles/18/981/2025