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Artificial Intelligence (AI) advancement is heavily dependent on access to large-scale, high-quality training data. However, in specialized domains such as healthcare, data acquisition faces significant constraints due to privacy regulations, ethical considerations, and limited availability. While synthetic data generation offers a promising solution, conventional approaches typically require substantial real data for training generative models. The emergence of large-scale prompt-based models presents new opportunities for synthetic data generation without direct access to protected data. However, crafting effective prompts for domain-specific data generation remains challenging, and manual prompt engineering proves insufficient for achieving output with sufficient precision and authenticity. We review recent developments in automatic prompt optimization, following PRISMA guidelines. We analyze six peer-reviewed studies published between 2020 and 2024 that focus on automatic data-free prompt optimization methods. Our analysis reveals three approaches: feedback-driven, error-based, and control-theoretic. Although all approaches demonstrate promising capabilities in prompt refinement and adaptation, our findings suggest the need for an integrated framework that combines complementary optimization techniques to enhance synthetic data generation while minimizing manual intervention. We propose future research directions toward developing robust, iterative prompt optimization frameworks capable of improving the quality of synthetic data. This advancement can be particularly crucial for sensitive fields and in specialized domains where data access is restricted, potentially transforming how we approach synthetic data generation for AI development., Comment: Accepted for publication in the Proceedings of the 2025 HCI International Conference

The destruction of metallicity due to the mutual Coulomb interaction of quasiparticles gives rise to fascinating phenomena of solid state physics such as the Mott metal-insulator transition and the pseudogap. A key observable characterizing their occurrences is the single-particle spectral function, determined by the fermionic self-energy. In this paper we investigate in detail how real space fluctuations are responsible for a self-energy that drives the Mott-Hubbard metal-insulator transition. To this aim we first introduce a real space fluctuation diagnostics approach to the Hedin equation, which connects the fermion-boson coupling vertex $\lambda$ to the self-energy $\Sigma$. Second, by using cellular dynamical mean-field theory calculations for $\lambda$ we identify the leading physical processes responsible for the destruction of metallicity across the transition., Comment: 21 pages, 17 figures

Previous Hubble Space Telescope (HST) observations of the star-forming cluster NGC 346 in the Small Magellanic Cloud (SMC) had revealed a large population of pre-main sequence (PMS) candidates, characterised by Halpha excess emission in their photometry. However, without access to spectroscopy, the nature of these objects remained unclear. Using the NIRSpec instrument on board JWST, we studied a sample of these stars, with masses in the range ~0.9-1.8 Msun, effective temperatures in the range 4,500-8,000 K, and PMS ages between ~0.1 and 30 Myr. Here we present the first spectra of solar-mass PMS stars in the metal-poor SMC (Z=1/8 Zsun) and discuss the physical properties of ten representative sources with good signal-to-noise ratio. The observations indicate that even the oldest of these PMS candidates are still accreting gas with typical rates of ~10^{-8} Msun/yr for stars older than ~10 Myr, confirming their PMS nature. The spectra also reveal near-infrared excess and molecular hydrogen excitation lines consistent with the presence of discs around these stars. These findings suggest that in a low-metallicity environment circumstellar discs can live longer than previously thought., Comment: 17 pages, 7 figures, to be published in The Astrophysical Journal, Vol 977, Article 214

Gallenene is a promising low-dimensional material with a structure down to the thickness of a single atom, similar to graphene. However, van der Waals stacking of two-dimensional (2D) gallenene under confinement remain poorly understood. In this study, we present evidence of the formation of parallel-stacked hexagonal gallenene (a100) structures in liquid gallium. The present study demonstrates the AB stacking of 2D gallenene a100 crystals in liquid gallium sandwiched between two graphene layers, as observed through transmission electron microscopy. A nonlinear optical response of the confined hexagonal gallenene was investigated through second harmonic generation (SHG) microscopy. The SHG signal exhibits periodic peak intensity shifts upon angular rotation up to 90 degrees and intensity dampening at elevated temperatures. These findings offer insights on device applications of 2D gallenene., Comment: 14 pages and 5 figures

We present an innovative optical imaging system for measuring parameters of a small particle such as a macromolecule or nanoparticle at the quantum limit of sensitivity. In comparison to the conventional confocal interferometric scattering (iSCAT) approach, our setup adds a second arm to form a Michelson interferometer that allows us to tune a relative phase. We evaluate the quantum Cram\'er-Rao bound (QCRB) for different quantum states, including single-mode coherent states, multi-frequency coherent states, and phase-averaged coherent states. Our results show that the proposed setup can achieve the QCRB of sensitivity and outperform iSCAT for all considered quantum states for mass and phase estimation of a particle.

In this paper, we present a novel approach for learning bimanual manipulation actions from human demonstration by extracting spatial constraints between affordance regions, termed affordance constraints, of the objects involved. Affordance regions are defined as object parts that provide interaction possibilities to an agent. For example, the bottom of a bottle affords the object to be placed on a surface, while its spout affords the contained liquid to be poured. We propose a novel approach to learn changes of affordance constraints in human demonstration to construct spatial bimanual action models representing object interactions. To exploit the information encoded in these spatial bimanual action models, we formulate an optimization problem to determine optimal object configurations across multiple execution keypoints while taking into account the initial scene, the learned affordance constraints, and the robot's kinematics. We evaluate the approach in simulation with two example tasks (pouring drinks and rolling dough) and compare three different definitions of affordance constraints: (i) component-wise distances between affordance regions in Cartesian space, (ii) component-wise distances between affordance regions in cylindrical space, and (iii) degrees of satisfaction of manually defined symbolic spatial affordance constraints., Comment: 8 pages, accepted for publication at Humanoids 2024 - Copyright IEEE

Testing and validating Cyber-Physical Systems (CPSs) in the aerospace domain, such as field testing of drone rescue missions, poses challenges due to volatile mission environments, such as weather conditions. While testing processes and methodologies are well established, structured guidance and execution support for field tests are still weak. This paper identifies requirements for field testing of drone missions, and introduces the Field Testing Scenario Management (FiTS) approach for adaptive field testing guidance. FiTS aims to provide sufficient guidance for field testers as a foundation for efficient data collection to facilitate quality assurance and iterative improvement of field tests and CPSs. FiTS shall leverage concepts from scenario-based requirements engineering and Behavior-Driven Development to define structured and reusable test scenarios, with dedicated tasks and responsibilities for role-specific guidance. We evaluate FiTS by (i) applying it to three use cases for a search-and-rescue drone application to demonstrate feasibility and (ii) interviews with experienced drone developers to assess its usefulness and collect further requirements. The study results indicate FiTS to be feasible and useful to facilitate drone field testing and data analysis, Comment: Accepted for publication at the 50th Euromicro Conference on Software Engineering and Advanced Applications (SEAA)

The blue compact dwarf galaxy I Zw 18 is one of the most metal-poor ($Z \sim 3% Z_{\sun}$) star-forming galaxies in the local Universe. Its evolutionary status has sparked debate within the astronomical community. We aim to investigate the stellar populations of I Zw 18 in the near-IR using JWST/NIRCam's high spatial resolution and sensitivity. Additionally, we aim to derive the galaxy's spatially resolved star formation history (SFH) over the last 1 Gyr and provide constraints for older epochs. We used DOLPHOT to measure positions and fluxes of point sources in the F115W and F200W filters' images of I Zw 18. To derive I Zw 18's SFH, we applied the color-magnitude diagram (CMD) fitting technique SFERA 2.0, using two independent sets of stellar models. Our analysis reveals three main stellar populations: one younger than $\sim30$ Myr, mainly in the northwest star-forming (SF) region; an intermediate-age population ($\sim 100 - 800$ Myr) in the southeast SF region; and a red and faint population linked to the underlying halo, older than 1 Gyr and possibly as old as 13.8 Gyr. The main body of the galaxy shows a very low star formation rate (SFR) of $\sim 10^{-4} M_{\odot} \text{yr}^{-1}$ between 1 and 13.8 Gyr ago. In the last billion years, I Zw 18 shows increasing SF, with strong bursts around $\sim10$ and $\sim100$ Myr ago. Component C mirrors the main body's evolution but with lower SFRs. Our findings confirm that I Zw 18 contains stars of all ages, indicating it is not a young galaxy but has an old stellar halo, similar to other BCDs. The low SF activity over the past billion years supports the "slow cooking" dwarf scenario, explaining its low metal content. Currently, the galaxy is undergoing its strongest SF episode ($\sim 0.6 M_{\odot} \text{yr}^{-1}$) mainly in the northwest region, likely due to a recent gravitational interaction with Component C., Comment: 14 pages, 11 figures, accepted for publications in Astronomy & Astrophysics (section "4. Extragalactic astronomy")

We present a JWST imaging survey with NIRCam and MIRI of NGC 346, the brightest star-forming region in the Small Magellanic Cloud (SMC). By combining aperture and point spread function (PSF) photometry of eleven wavelength bands across these two instruments, we have detected more than 200,000 unique sources. Using near-infrared (IR) color analysis, we observe various evolved and young populations, including 196 young stellar objects (YSOs) and pre-main sequence stars suitable for forthcoming spectroscopic studies. We expand upon this work, creating mid-IR color-magnitude diagrams and determining color cuts to identify 833 reddened sources which are YSO candidates. We observe that these candidate sources are spatially associated with regions of dusty, filamentary nebulosity. Furthermore, we fit model YSO spectral energy distributions (SEDs) to a selection of sources with detections across all of our MIRI bands. We classify with a high degree of confidence 23 YSOs in this sample and estimate their radii, bolometric temperatures, luminosities, and masses. We detect YSOs approaching 1 solar mass, the lowest-mass extragalactic YSOs confirmed to date.

JWST/NIRCam obtained high angular-resolution (0.05-0.1''), deep near-infrared 1--5 micron imaging of Supernova (SN) 1987A taken 35 years after the explosion. In the NIRCam images, we identify: 1) faint H2 crescents, which are emissions located between the ejecta and the equatorial ring, 2) a bar, which is a substructure of the ejecta, and 3) the bright 3-5 micron continuum emission exterior to the equatorial ring. The emission of the remnant in the NIRCam 1-2.3 micron images is mostly due to line emission, which is mostly emitted in the ejecta and in the hot spots within the equatorial ring. In contrast, the NIRCam 3-5 micron images are dominated by continuum emission. In the ejecta, the continuum is due to dust, obscuring the centre of the ejecta. In contrast, in the ring and exterior to the ring, synchrotron emission contributes a substantial fraction to the continuum. Dust emission contributes to the continuum at outer spots and diffuse emission exterior to the ring, but little within the ring. This shows that dust cooling and destruction time scales are shorter than the synchrotron cooling time scale, and the time scale of hydrogen recombination in the ring is even longer than the synchrotron cooling time scale. With the advent of high sensitivity and high angular resolution images provided by JWST/NIRCam, our observations of SN 1987A demonstrate that NIRCam opens up a window to study particle-acceleration and shock physics in unprecedented details, probed by near-infrared synchrotron emission, building a precise picture of how a SN evolves., Comment: Accepted for publication in MNRAS; 18 pages

We present a JWST imaging survey of I Zw 18, the archetypal extremely metal-poor, star-forming (SF), blue compact dwarf galaxy. With an oxygen abundance of only $\sim$3% $Z_{\odot}$, it is among the lowest-metallicity systems known in the local Universe, and is, therefore, an excellent accessible analog for the galactic building blocks which existed at early epochs of ionization and star formation. These JWST data provide a comprehensive infrared (IR) view of I Zw 18 with eight filters utilizing both Near Infrared Camera (F115W, F200W, F356W, and F444W) and Mid-Infrared Instrument (F770W, F1000W, F1500W, and F1800W) photometry, which we have used to identify key stellar populations that are bright in the near- and mid-IR. These data allow for a better understanding of the origins of dust and dust-production mechanisms in metal-poor environments by characterizing the population of massive, evolved stars in the red supergiant (RSG) and asymptotic giant branch (AGB) phases. In addition, it enables the identification of the brightest dust-enshrouded young stellar objects (YSOs), which provide insight into the formation of massive stars at extremely low metallicities typical of the very early Universe. This paper provides an overview of the observational strategy and data processing, and presents first science results, including identifications of dusty AGB, RSG, and bright YSO candidates. These first results assess the scientific quality of JWST data and provide a guide for obtaining and interpreting future observations of the dusty and evolved stars inhabiting compact dwarf SF galaxies in the local Universe., Comment: Accepted for publication in The Astronomical Journal; 25 pages, 14 figures, 4 tables

The nearby Supernova 1987A was accompanied by a burst of neutrino emission, which indicates that a compact object (a neutron star or black hole) was formed in the explosion. There has been no direct observation of this compact object. In this work, we observe the supernova remnant with JWST spectroscopy finding narrow infrared emission lines of argon and sulphur. The line emission is spatially unresolved and blueshifted in velocity relative to the supernova rest frame. We interpret the lines as gas illuminated by a source of ionizing photons located close to the center of the expanding ejecta. Photoionization models show that the line ratios are consistent with ionization by a cooling neutron star or pulsar wind nebula. The velocity shift could be evidence for a neutron star natal kick., Comment: Authors version of manuscript published in Science on 22 Feb 2024

There exist very few mid-infrared (IR) observations of supernovae (SNe) in general. Therefore, SN 1987A, the closest visible SN in 400 years, gives us the opportunity to explore the mid-IR properties of SNe, the dust in their ejecta and surrounding medium, and to witness the birth of a SN remnant (SNR). The James Webb Space Telescope (JWST), with its high spatial resolution and extreme sensitivity, gives a new view on these issues. We report on the first imaging observations obtained with the Mid-InfraRed Instrument (MIRI). We build temperature maps and discuss the morphology of the nascent SNR. Our results show that the temperatures in the equatorial ring (ER) are quite non-uniform. This could be due to dust destruction in some parts of the ring, as had been assumed in some previous works. We show that the IR emission extends beyond the ER, illustrating the fact that the shock wave has now passed through this ring to affect the circumstellar medium on a larger scale. Finally, while sub-mm Atacama Large Millimeter Array (ALMA) observations have hinted at the location of the compact remnant of SN 1987A, we note that our MIRI data have found no such evidence., Comment: 19 pages, 19 figures, 2 tables; Accepted for publication in the Astrophysical Journal (February 2, 2024)

Cyber-Physical Production Systems (CPPSs), such as automated car manufacturing plants, execute a configurable sequence of production steps to manufacture products from a product portfolio. In CPPS engineering, domain experts start with manually determining feasible production step sequences and resources based on implicit knowledge. This process is hard to reproduce and highly inefficient. In this paper, we present the Extended Iterative Process Sequence Exploration (eIPSE) approach to derive variability models for products, processes, and resources from a domain-specific description. To automate the integrated exploration and configuration process for a CPPS, we provide a toolchain which automatically reduces the configuration space and allows to generate CPPS artifacts, such as control code for resources. We evaluate the approach with four real-world use cases, including the generation of control code artifacts, and an observational user study to collect feedback from engineers with different backgrounds. The results confirm the usefulness of the eIPSE approach and accompanying prototype to straightforwardly configure a desired CPPS., Comment: 26 pages, 10 figures

Movement primitives (MPs) are compact representations of robot skills that can be learned from demonstrations and combined into complex behaviors. However, merely equipping robots with a fixed set of innate MPs is insufficient to deploy them in dynamic and unpredictable environments. Instead, the full potential of MPs remains to be attained via adaptable, large-scale MP libraries. In this paper, we propose a set of seven fundamental operations to incrementally learn, improve, and re-organize MP libraries. To showcase their applicability, we provide explicit formulations of the spatial operations for libraries composed of Via-Point Movement Primitives (VMPs). By building on Riemannian manifold theory, our approach enables the incremental learning of all parameters of position and orientation VMPs within a library. Moreover, our approach stores a fixed number of parameters, thus complying with the essential principles of incremental learning. We evaluate our approach to incrementally learn a VMP library from motion capture data provided sequentially., Comment: This work has been submitted to the IEEE for possible publication. 7 pages, 7 figures and 2 tables

PRIMA (The PRobe for-Infrared Mission for Astrophysics) is a concept for a far-infrared (IR) observatory. PRIMA features a cryogenically cooled 1.8 m diameter telescope and is designed to carry two science instruments enabling ultra-high sensitivity imaging and spectroscopic studies in the 24 to 235 microns wavelength range. The resulting observatory is a powerful survey and discovery machine, with mapping speeds better by 2 - 4 orders of magnitude with respect to its far-IR predecessors. The bulk of the observing time on PRIMA should be made available to the community through a General Observer (GO) program offering 75% of the mission time over 5 years. In March 2023, the international astronomy community was encouraged to prepare authored contributions articulating scientific cases that are enabled by the telescope massive sensitivity advance and broad spectral coverage, and that could be performed within the context of GO program. This document, the PRIMA General Observer Science Book, is the edited collection of the 76 received contributions., Comment: A. Moullet, T. Kataria, D. Lis, S. Unwin, Y. Hasegawa, E. Mills, C. Battersby, A. Roc, M. Meixner are the editors of the PRIMA General Observer Science Book. The book compiles 76 authored contributions. 399 pages

The recently proposed center-focused post-processing procedure [Phys. Rev. Research 2, 033476 (2020)] of cellular dynamical mean-field theory suggests that central sites of large impurity clusters are closer to the exact solution of the Hubbard model than the edge sites. In this paper, we systematically investigate results in the spirit of this center-focused scheme for several cluster sizes up to $8\times 8$ in and out of particle-hole symmetry. First we analyze the metal-insulator crossovers and transitions of the half-filled Hubbard model on a simple square lattice. We find that the critical interaction of the crossover is reduced with increasing cluster sizes and the critical temperature abruptly drops for the $4\times 4$ cluster. Second, for this cluster size, we apply the center-focused scheme to a system with more realistic tight-binding parameters, investigating its pseudogap regime as a function of temperature and doping, where we find doping dependent metal-insulator crossovers, Lifshitz transitions and a strongly renormalized Fermi-liquid regime. Additionally to diagnosing the real space origin of the suppressed antinodal spectral weight in the pseudogap regime, we can infer hints towards underlying charge ordering tendencies., Comment: 31 pages, 16 figures

During hurricanes, coupled wave-circulation models are critical tools for public safety. The standard approach is to use a high fidelity circulation model coupled with a wave model which uses the most advanced source terms. As a result, the models can be highly computationally expensive and so this study investigates the potential consequences of using highly simplified (reduced order) source terms within the wave model component of the coupled wave-circulation model. The trade-off between run time and accuracy with respect to observations is quantified for a set of two storms that impacted the Gulf of Mexico, Hurricane Ike and Hurricane Ida. Water surface elevations as well as wave statistics (significant wave height, peak period, and mean wave direction) are compared to observations. The usage of the reduced order source terms yielded significant savings in computational cost. Additionally, relatively low amounts of additional error with respect to observations during the simulations with reduced order source terms. However, large changes in global model outputs of the wave statistics were observed based on the choice of source terms particularly near the track of each hurricane.

NGC 6822 is a nearby (~490 kpc) non-interacting low-metallicity (0.2 Zsolar) dwarf galaxy which hosts several prominent H ii regions, including sites of highly embedded active star formation. In this work, we present an imaging survey of NGC 6822 conducted with the NIRCam and MIRI instruments onboard JWST. We describe the data reduction, source extraction, and stellar population identifications from combined near- and mid-infrared (IR) photometry. Our NIRCam observations reach seven magnitudes deeper than previous JHKs surveys of this galaxy, which were sensitive to just below the tip of the red giant branch (TRGB). These JWST observations thus reveal for the first time in the near-IR the red clump stellar population and extend nearly three magnitudes deeper. In the mid-IR, we observe roughly two magnitudes below the TRGB with the MIRI F770W and F1000W filters. With these improvements in sensitivity, we produce a catalogue of ~900,000 point sources over an area of ~ 6.0 x 4.3 arcmin2. We present several NIRCam and MIRI colour-magnitude diagrams and discuss which colour combinations provide useful separations of various stellar populations to aid in future JWST observation planning. Finally, we find populations of carbon- and oxygen-rich asymptotic giant branch stars which will assist in improving our understanding of dust production in low-metallicity, early Universe analogue galaxies, Comment: 17 pages, 8 figures, 7 tables, accepted MNRAS

The prediction of the wind wave spectrum of the ocean using numerical models are an important tool for researchers, engineers, and communities living in coastal areas. The governing equation of the wind wave models, the Wave Action Balance Equation, presents unique challenges for implementing reliable numerical models because it is highly advective, highly nonlinear and high dimensional. Historically, most operational models have utilized finite difference methods, others have used finite volume methods but relatively few attempts at using finite element methods. In this work, we seek to fill this gap by investigating several different finite element discretizations of the Wave Action Balance Equation. The methods, which include streamline upwind Petrov-Galerkin (SUPG), least squares, and discontinuous Galerkin, are implemented and convergence properties are examined for some simplified 2-D test cases. Then, a new spectral wind wave model, WAVEx, is formulated and implemented for the full problem setting. WAVEx uses continuous finite elements along with SUPG stabilization in geographic/spectral space that allows for fully unstructured triangular meshes in both geographic and spectral space. For propagation in time, a second order fully implicit finite difference method is used. When source terms are active, a second order operator splitting scheme is used to linearize the problem. In the splitting scheme, propagation is solved using the implicit method and the nonlinear source terms are treated explicitly. Several test cases, including analytic tests and laboratory experiments, are demonstrated and results are compared to analytic solutions, observations, as well as output from another model that is used operationally.

We present an imaging survey of the Spitzer I star-forming region in NGC 6822 conducted with the NIRCam and MIRI instruments onboard JWST. Located at a distance of 490 kpc, NGC 6822 is the nearest non-interacting low-metallicity ($\sim$0.2 $Z_{\odot}$) dwarf galaxy. It hosts some of the brightest known HII regions in the local universe, including recently discovered sites of highly-embedded active star formation. Of these, Spitzer I is the youngest and most active, and houses 90 color-selected candidate young stellar objects (YSOs) identified from Spitzer Space Telescope observations. We revisit the YSO population of Spitzer I with these new JWST observations. By analyzing color-magnitude diagrams (CMDs) constructed with NIRCam and MIRI data, we establish color selection criteria and construct spectral energy distributions (SEDs) to identify candidate YSOs and characterize the full population of young stars, from the most embedded phase to the more evolved stages. In this way, we have identified 140 YSOs in Spitzer I. Comparing to previous Spitzer studies of the NGC 6822 YSO population, we find that the YSOs we identify are fainter and less massive, indicating that the improved resolution of JWST allows us to resolve previously blended sources into multiple objects., Comment: 17 pages, 9 figures, 2 tables, ApJ accepted

The generation of energy-efficient and dynamic-aware robot motions that satisfy constraints such as joint limits, self-collisions, and collisions with the environment remains a challenge. In this context, Riemannian geometry offers promising solutions by identifying robot motions with geodesics on the so-called configuration space manifold. While this manifold naturally considers the intrinsic robot dynamics, constraints such as joint limits, self-collisions, and collisions with the environment remain overlooked. In this paper, we propose a modification of the Riemannian metric of the configuration space manifold allowing for the generation of robot motions as geodesics that efficiently avoid given regions. We introduce a class of Riemannian metrics based on barrier functions that guarantee strict region avoidance by systematically generating accelerations away from no-go regions in joint and task space. We evaluate the proposed Riemannian metric to generate energy-efficient, dynamic-aware, and collision-free motions of a humanoid robot as geodesics and sequences thereof., Comment: Accepted for publication in IEEE/RSJ Intl. Conf. on Intelligent Robots and Systems (IROS) 2023. 8 pages, 7 figures, accompanying video at https://youtu.be/qT43XgYOlU0

The aim of this work is to investigate the structural and magnetic characteristics of Fe thin films with a triangular (hexagonal) lattice surfaces (fcc (111) and bcc (111)). The properties of these structures have been calculated using density functional theory (DFT) implemented in the full-potential local-orbital(FPLO) code. The results indicate a structural phase transition from fcc to bcc structure when the film thickness exceeds 23 Fe atomic monolayers. The considered fcc films prefer the low-spin ferromagnetic state with an average magnetic moment of about 1.0 $\mu_{B}$ per atom. This moment decreases with increasing film thickness until the critical thickness, where, after the structural transition to the bcc phase, it reaches a value close to that of bulk bcc Fe. Moreover, the values of the magnetic anisotropy energy are positive (perpendicular magnetic anisotropy) for the entire thickness range of films with fcc structure (in ferromagnetic low-spin state) and systematically decrease with increasing film thickness. The presented computational results explain the experimentally observed structural transition and may help to select appropriate substrates with suitable lattice parameters for the deposition of ultrathin Fe(111) films., Comment: submitted to Journal of Magnetism and Magnetic Materials

Supernova (SN) 1987A is the nearest supernova in $\sim$400 years. Using the {\em JWST} MIRI Medium Resolution Spectrograph, we spatially resolved the ejecta, equatorial ring (ER) and outer rings in the mid-infrared 12,927 days after the explosion. The spectra are rich in line and dust continuum emission, both in the ejecta and the ring. Broad emission lines (280-380~km~s$^{-1}$ FWHM) seen from all singly-ionized species originate from the expanding ER, with properties consistent with dense post-shock cooling gas. Narrower emission lines (100-170~km~s$^{-1}$ FWHM) are seen from species originating from a more extended lower-density component whose high ionization may have been produced by shocks progressing through the ER, or by the UV radiation pulse associated with the original supernova event. The asymmetric east-west dust emission in the ER has continued to fade, with constant temperature, signifying a reduction in dust mass. Small grains in the ER are preferentially destroyed, with larger grains from the progenitor surviving the transition from SN into SNR. The ER is fit with a single set of optical constants, eliminating the need for a secondary featureless hot dust component. We find several broad ejecta emission lines from [Ne~{\sc ii}], [Ar~{\sc ii}], [Fe~{\sc ii}], and [Ni~{\sc ii}]. With the exception of [Fe~{\sc ii}]~25.99$\mu$m, these all originate from the ejecta close to the ring and are likely being excited by X-rays from the interaction. The [Fe~{\sc ii}]~5.34$\mu$m to 25.99$\mu$m line ratio indicates a temperature of only a few hundred K in the inner core, consistent with being powered by ${}^{44}$Ti decay., Comment: 27 pages, 16 figures, 4 tables. Accepted ApJ

"Divisive concepts" legislation, which seeks to restrict teaching about topics like race, gender, and sexuality, for example, has proliferated across the United States, creating confusion and challenges for students, teachers, and teacher educators who want to include discussion of complex topics in their classrooms (Ervin & Gannon, 2024; PEN America, 2023; Schoorman & Gatens, 2024; Woo et al., 2023). In March of 2024, National Council of Teachers of English (NCTE) leadership sent a survey to NCTE members to solicit needs for facilitating discussion of complex topics in ELA classrooms. In response, NCTE members emphasized teachers' responsibility to teach whole histories and full narratives, and they requested support on how to do this well when discussing complex topics. In this survey and beyond, members have requested support in discussing race and racism, political and civil unrest, LGBTQIA+ peoples' experiences and struggles, the upcoming presidential election, pandemic vaccination policies, reproductive rights, and other current and complex topics. Aligned with the NCTE mission and vision, the NCTE Executive Committee reiterates NCTE's commitments to fighting against censorship, uplifting diverse voices and perspectives, and supporting critical literacy instruction. To fully participate in society, students need to be able to grapple with the very topics that are being pushed out of the classroom by divisive concepts legislation and other methods of censorship. As educators consider the integration of complex topics into learning spaces, it also becomes essential to provide a variety of experiences and texts that highlight the nuances of these topics. Inquiry frameworks, discussion protocols, community experts, and transparent communication and engagement with families can all contribute to positive teaching and learning experiences.

Defect engineering is promising to tailor the physical properties of two-dimensional (2D) semiconductors for function-oriented electronics and optoelectronics. Compared with the extensively studied 2D binary materials, the origin of defects and their influence on physical properties of 2D ternary semiconductors have not been clarified. In this work, we thoroughly studied the effect of defects on the electronic structure and optical properties of few-layer hexagonal Znln2S4 via versatile spectroscopic tools in combination with theoretical calculations. It has been demonstrated that the Zn-In anti-structural defects induce the formation of a series of donor and acceptor levels inside the bandgap, leading to rich recombination paths for defect emission and extrinsic absorption. Impressively, the emission of donor-acceptor pair (DAP) in Znln2S4 can be significantly tailored by electrostatic gating due to efficient tunability of Fermi level (Ef). Furthermore, the layer-dependent dipole orientation of defect emission in Znln2S4 was directly revealed by back focal plane (BFP) imagining, where it presents obviously in-plane dipole orientation within a dozen layers thickness of Znln2S4. These unique features of defects in Znln2S4 including extrinsic absorption, rich recombination paths, gate tunability and in-plane dipole orientation will definitely benefit to the advanced orientation-functional optoelectronic applications.

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit., Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figures

We present initial results from JWST NIRSpec integral field unit observations of the nearby Supernova (SN) 1987A. The observations provide the first spatially-resolved spectroscopy of the ejecta and equatorial ring (ER) over the 1-5 \mu m range. We construct 3D emissivity maps of the [Fe I] 1.443 \mu m line from the inner ejecta and the He I 1.083 \mu m line from the reverse shock (RS), where the former probes the explosion geometry and the latter traces the structure of the circumstellar medium. We also present a model for the integrated spectrum of the ejecta. The [Fe I] 3D map reveals a highly-asymmetric morphology resembling a broken dipole, dominated by two large clumps with velocities of ~2300 km/s. We also find evidence that the Fe-rich inner ejecta have started to interact with the RS. The RS surface traced by the He I line extends from just inside the ER to higher latitudes on both sides of the ER with a half-opening angle ~45 degrees, forming a bubble-like structure. The spectral model for the ejecta allows us to identify the many emission lines, including numerous H_2 lines. We find that the H_2 is most likely excited by far-UV emission, while the metal lines ratios are consistent with a combination of collisional excitation and recombination in the low-temperature ejecta. We also find several high-ionization coronal lines from the ER, requiring a temperature > 2 \times 10^6 K., Comment: Accepted for publication in ApJL

We present new Hubble Space Telescope WFC3/IR medium-band photometry of the compact elliptical galaxy M32, chemically resolving its thermally pulsating asymptotic giant branch stars. We find 2829 M-type stars and 57 C stars. The carbon stars are likely contaminants from M31. If carbon stars are present in M32 they are so in very low numbers. The uncorrected C/M ratio is 0.020 $\pm$ 0.003; this drops to less than 0.007 after taking into account contamination from M31. As the mean metallicity of M32 is just below solar, this low ratio of C to M stars is unlikely due to a metallicity ceiling for the formation of carbon stars. Instead, the age of the AGB population is likely to be the primary factor. The ratio of AGB to RGB stars in M32 is similar to that of the inner disc of M31 which contain stars that formed 1.5-4 Gyr ago. If the M32 population is at the older end of this age then its lack of C-stars may be consistent with a narrow mass range for carbon star formation predicted by some stellar evolution models. Applying our chemical classifications to the dusty variable stars identified with {\em Spitzer}, we find that the x-AGB candidates identified with Spitzer are predominately M-type stars. This substantially increases the lower limit to the cumulative dust-production rate in M32 to $>$ 1.20 $\times 10^{-5}$ ${\rm M}_{\odot} \, {\rm yr}^{-1}$., Comment: 10 pages, 7 figures, accepted MNRAS

A tremendous amount of radiation is emitted by the Interstellar Medium in the mid- and far-infrared (3-500 {\mu}m) that represents the majority of the light emitted by a galaxy. In this article we motivate ISM studies in the infrared and the construction of large specialized observatories like the Stratospheric Observatory For Infrared Astronomy (SOFIA), which just concluded its mission on a scientific high note, and the newly launched James Webb Space Telescope (JWST) that just begun its exciting scientific mission. We introduce their capabilities, present a few examples of their scientific discoveries and discuss how they complemented each other. We then consider the impact of the conclusion of SOFIA for the field in a historic context and look at new opportunities specifically for far-infrared observatories in space and in the stratosphere.