We report the detection of six new galaxy candidates with photometric redshifts z > 11 within the James Webb Space Telescope (JWST) Advanced Deep Extragalactic Survey (JADES) Great Observatories Origins Deep Survey-South (GOODS-S) and GOODS-North (GOODS-N) fields. These new candidates are detected through meticulous analysis of NIRCam (Near-Infrared Camera) photometry in eight filters spanning a wavelength range of 0.8-5.0 mu m. Photometric redshifts of these galaxy candidates are independently measured utilizing spectral energy distribution fitting techniques using eazy and bagpipes codes, followed by visual scrutiny. One of these galaxy candidates is located in the GOODS-S field, while the remaining five galaxies are located in GOODS-N field. Our analysis reveals that the stellar masses of these galaxies typically range from log M-*/M-circle dot = 7.75 to 8.75. Furthermore, these galaxies are typically young with their mass-weighted ages spanning from 80 to 240 Myr. Their specific star formation rates, quantified as log(sSFR/Gyr), are measured to vary between similar to 0.95and 1.46. These new galaxy candidates offer a robust sample for probing the physical properties of galaxies within the first few hundred Myr of the history of the Universe. We also analyse the relationship between star formation rate and stellar mass (M-*) within our sample. Continued investigation through spectroscopic analysis using JWST/Near-Infrared Spectrograph (NIRSpec) is needed to spectroscopically confirm these high-redshift galaxy candidates and investigate further into their physical properties. We plan to follow-up on these candidates with future NIRSpec observations.

We propose to add instruments to any potential future X-ray mission with focussing optics that is considered in NASA's ASTRA framework. Such an instrument is a necessity to study AGN wind outflows and feedback, find the missing baryons, study the intergalactic medium, and analyze abundances and chemical bonds in dust grains throughout the Milky Way. We conclude that those science goals can be achieved with a spectral resolving power > 3000 in the soft X-ray band (about 10-40 Ang) and an effective area a few times larger than current instruments. We describe a possible mission implementation for a soft X-ray grating spectrometer that can be folded in and out or be mounted permanently in the beam. Such an instrument can reach the requirements for a wide variety of host mission properties. A small UV imager and a UV spectrograph can be mounted on the same platform with independent optics. These added instruments vastly enhance the science capabilities of the host mission for a modest cost (100-200 million $) and with weight and power needs that can be easily accommodated in any major mission.

The X-ray Imaging Spectroscopy Mission (XRISM) provides the best spectral resolution with which to study sulfur (S) K-shell photoabsorption features from the interstellar medium (ISM). For the first time, we demonstrate the high-signal detection of interstellar atomic S ii K-beta absorption in the spectrum of X-ray binaries (XRBs) 4U 1630-472 and GX 340$+$0. The persistence of this feature across multiple instruments, targets, and flux states implies that it is interstellar in nature. We measure the S ii K$\beta$ line centroid at $2470.8 \pm 1.1$ eV after including systematic uncertainties. We also find that the most recently published high-resolution S ii absorption template requires a systematic energy scale shift of $+7\!-\!8$ eV, which is comparable to the level of disagreement among various atomic modeling procedures. The XRISM 300 ks observation of GX 340$+$0 provides unprecedented signal-to-noise in the S K region, and we find evidence of residual absorption from solid S in the spectra of GX 340$+$0. Absorption templates from three Fe-S compounds, troilite (FeS), pyrrhotite (Fe$_7$S$_8$) and pyrite (FeS$_2$), provide equally good fits to the residuals. Even though we are not able to distinguish among these three compounds, they provide equal estimates for the abundance of S locked in dust grains. Having accounted for both the gaseous and solid S in the GX 340$+$0 sightline provides us with a direct measurement of S depletion, which is $40{\%} \pm 15\%$. Our depletion measurement provides an upper limit to the fraction of interstellar Fe bound in Fe-S compounds of ${<}25\%$, which is consistent with prior studies of Fe-S compounds via Fe L-shell absorption. Both XRBs in this study are at a distance of approximately 11 kpc and on the opposite side of the Galactic disk, suggesting that this value could represent the average S depletion of the Milky Way when integrated across all phases of the ISM.

Dark matter-dominated cores have long been claimed for the well-studied local group dwarf galaxies. More recently, extended stellar halos have been uncovered around several of these dwarfs through deeper imaging and spectroscopy. Such core-halo structures are not a feature of conventional cold dark matter (CDM), based on collisionless particles where smooth, scale-free profiles are predicted. In contrast, smooth and prominent dark matter cores are predicted for Warm and Fuzzy/Wave Dark Matter (WDM/$\psi$DM) respectively. The question arises to what extent the visible stellar profiles should reflect this dark matter core structure. Here we compare cosmological hydrodynamical simulations of CDM, WDM $\&$ $\psi$DM, aiming to predict the stellar profiles for these three DM scenarios. We show that cores surrounded by extended halos are distinguishable for WDM and $\psi$DM, with the most prominent cores in the case of $\psi$DM, where the stellar density is enhanced in the core due to the presence of the relatively dense soliton. Our analysis demonstrates that such behavior does not appear in CDM, implying that the small-scale cut-off in the power spectrum present for WDM and $\psi$DM provides a core-halo transition. Consequently, we estimate the mass of the $\psi$DM particle at this core-halo transition point. Furthermore, we observe the anticipated asymmetry for $\psi$DM due to the soliton's random walk, a distinctive characteristic not found in the symmetric distributions of stars in Warm and CDM models.

Electron beam ion traps (EBITs) are compact devices optimized for producing ions in high charge states for spectroscopic studies or as extracted beams. Key characteristics, such as current density and electron-ion overlap, govern ionization and excitation rates. Using visible and X-ray imaging of emissions from highly charged ions, the spatial distributions of the electron beam and ion cloud in the Smithsonian Astrophysical Observatory (SAO) EBIT were measured, enabling the determination of the effective electron density. The nominal electron beam full width at half maximum (FWHM) was determined to be 92.0 ± 9.7 μm, while the ion cloud FWHM was 410.5 ± 16.5 μm, indicating an effective electron density roughly an order of magnitude lower than determined geometrically. The effects of magnetic fields on the electron beam size were also investigated, demonstrating sensitivity to the focusing magnet and bucking coil currents. These findings emphasize the need for simultaneous measurement of the effective electron density to improve the accuracy of density-sensitive studies in EBIT systems.

Arcus is a high-resolution soft X-ray and far-ultraviolet spectroscopy mission submitted to the National Aeronautics and Space Administration's inaugural Astrophysics Probe solicitation. Arcus makes simultaneous observations in these two critical wavelength regimes to address a broad range of science questions highlighted by the 2020 Astronomy and Astrophysics Decadal Survey, from the temperature and composition of the missing baryons in the intergalactic medium to the evolution of stars and their influence on orbiting planets. We present the science motivation for and performance of the Arcus ultraviolet spectrograph (UVS). UVS comprises a 60-cm, off-axis Cassegrain telescope feeding an imaging spectrograph operating over the 970- to 1580-angstrom bandpass. The instrument employs two interchangeable diffraction gratings to provide medium-resolution spectroscopy (R>20,000 in two grating modes centered at similar to 1110 and 1390 angstrom). The spectra are recorded on an open-face, photon-counting microchannel plate detector. The instrument design achieves an end-to-end sensitivity >10 times that of the Far-Ultraviolet Spectroscopic Explorer over the key 1020- to 1150-angstrom range and offers arcsecond-level angular resolution spectral imaging over a 6-arcminute-long slit for observations of extended sources. We describe the example science investigations for far-ultraviolet spectroscopy on Arcus, the resultant instrument design and predicted performance, and simulated data from potential General Observer programs with Arcus.

We undertake a comprehensive investigation into the distribution of in situ stars within Milky Way-like galaxies, leveraging TNG50 simulations and comparing their predictions with data from the H3 survey. Our analysis reveals that 28% of galaxies demonstrate reasonable agreement with H3, while only 12% exhibit excellent alignment in their profiles, regardless of the specific spatial cut employed to define in situ stars. To uncover the underlying factors contributing to deviations between TNG50 and H3 distributions, we scrutinise correlation coefficients among internal drivers (e.g. virial radius, star formation rate [SFR]) and merger-related parameters (such as the effective mass-ratio, mean distance, average redshift, total number of mergers, average spin-ratio, and maximum spin alignment between merging galaxies). Notably, we identify significant correlations between deviations from observational data and key parameters such as the median slope of virial radius, mean SFR values, and the rate of SFR change across different redshift scans. Furthermore, positive correlations emerge between deviations from observational data and parameters related to galaxy mergers. We validate these correlations using the Random Forest Regression method. Our findings underscore the invaluable insights provided by the H3 survey in unravelling the cosmic history of galaxies akin to the Milky Way, thereby advancing our understanding of galactic evolution and shedding light on the formation and evolution of Milky Way-like galaxies in cosmological simulations.

In this report we describe the design and operation of the electron beam ion trap (EBIT) at the Smithsonian Astrophysical Observatory (SAO). We also provide an overview of recent upgrades that have led to improved system stability and greater user control, increasing the scope of possible experiments. Observations of X-ray emission from background elements were made after the system upgrades. The evolution of the spectrum, produced at beam energies ranging from 1285 eV to 3095 eV, allowed us to identify emission from multiple charge states and from key processes, such as dielectronic recombination, in Ba and Si ions. Emission from these background elements was easily removed by periodically dumping the trap every 2 s or less.

Charge-exchange recombination with neutral atoms significantly influences the ionization balance in electron beam ion traps (EBIT) because its cross section is relatively large compared to cross sections of electron collision induced processes. Modeling the highly charged ion cloud requires the estimate of operating parameters, such as electron beam energy and density, the density of neutral atoms, and the relative velocities of collision partners. Uncertainty in the charge-exchange cross section can dominate the overall uncertainty in EBIT experiments, especially when it compounds with the uncertainties of experimental parameters that are difficult to determine. We present measured and simulated spectra of few-electron Fe ions, where we used a single charge-exchange factor to reduce the number of free parameters in the model. The deduction of the charge-exchange factor from the ratio of Li-like and He-like features allows for predicting the intensity of H-like lines in the spectra.

We present an analysis of the first two XRISM/Resolve spectra of the well-known Seyfert-1.5 active galactic nucleus (AGN) in NGC 4151, obtained in 2023 December. Our work focuses on the nature of the narrow Fe K-alpha emission line at 6.4 keV, the strongest and most common X-ray line observed in AGN. The total line is found to consist of three components. Even the narrowest component of the line is resolved with evident Fe K-alpha,K-1 (6.404 keV) and K-alpha,K-2 (6.391 keV) contributions in a 2:1 flux ratio, fully consistent with neutral gas with negligible bulk velocity. Subject to the limitations of our models, the narrowest and intermediate-width components are consistent with emission from optically thin gas, suggesting that they arise in a disk atmosphere and/or wind. Modeling the three line components in terms of Keplerian broadening, they are readily associated with (1) the inner wall of the "torus," (2) the innermost optical "broad-line region" (or "X-ray BLR"), and (3) a region with a radius of r similar or equal to 100 GM/c(2) that may signal a warp in the accretion disk. Viable alternative explanations of the broadest component include a fast-wind component and/or scattering; however, we find evidence of variability in the narrow Fe K-alpha line complex on timescales consistent with small radii. The best-fit models are statistically superior to simple Voigt functions, but when fit with Voigt profiles the time-averaged lines are consistent with a projected velocity broadening of FWHM = 1600(-200)(+400) km s(-1). Overall, the resolution and sensitivity of XRISM show that the narrow Fe K line in AGN is an effective probe of all key parts of the accretion flow, as it is currently understood. We discuss the implications of these findings for our understanding of AGN accretion, future studies with XRISM, and X-ray-based black hole mass measurements.

Sagittarius A East is a supernova remnant with a unique surrounding environment, as it is located in the immediate vicinity of the supermassive black hole at the Galactic center, Sagittarius A*. The X-ray emission of the remnant is suspected to show features of overionized plasma, which would require peculiar evolutionary paths. We report on the first observation of Sagittarius A East with the X-Ray Imaging and Spectroscopy Mission(XRISM). Equipped with a combination of a high-resolution microcalorimeter spectrometer and a large field-of-view CCD imager, we for the first time resolved the Fe XXV K-shell lines into fine structure lines and measured the forbidden-to-resonance intensity ratio to be 1.39 +/- 0.12, which strongly suggests the presence of overionized plasma. We obtained a reliable constraint on the ionization temperature just before the transition into the overionization state, of > 4 keV. The recombination timescale was constrained to be < 8 x10(11) cm(-3) s. The small velocity dispersion of 109 +/- 6 km s(-1) indicates a low Fe ion temperature < 8 keV and a small expansion velocity < 200 km s(-1). The high initial ionization temperature and small recombination timescale suggest that either rapid cooling of the plasma via adiabatic expansion from dense circumstellar material or intense photoionization by Sagittarius A* in the past may have triggered the overionization.

We present an in-depth analysis of gas morphologies for a sample of 25 Milky Way-like galaxies from the IllustrisTNG TNG50 simulation. We constrain the morphology of cold, warm, hot gas, and gas particles as a whole using a Local Shell Iterative Method (LSIM) and explore its observational implications by computing the hard-to-soft X-ray ratio, which ranges between $10^{-3}$-$10^{-2}$ in the inner $\sim 50 \rm kpc$ of the distribution and $10^{-5}$-$10^{-4}$ at the outer portion of the hot gas distribution. We group galaxies into three main categories: simple, stretched, and twisted. These categories are based on the radial reorientation of the principal axes of the reduced inertia tensor. We find that a vast majority ($77\%$) of the galaxies in our sample exhibit twisting patterns in their radial profiles. Additionally, we present detailed comparisons between 1) the gaseous distributions belonging to individual temperature regimes, 2) the cold gas distributions and stellar distributions, and 3) the gaseous distributions and dark matter (DM) halos. We find a strong correlation between the morphological properties of the cold gas and stellar distributions. Furthermore, we find a correlation between gaseous distributions with DM halo that increases with gas temperature, implying that we may use the warm-hot gaseous morphology as a tracer to probe the DM morphology. Finally, we show gaseous distributions exhibit significantly more prolate morphologies than the stellar distributions and DM halos, which we hypothesize is due to stellar and AGN feedback.

High resolving power soft x-ray spectroscopy has been confirmed by the Astro2020 Decadal Survey as a highpriority strategic measurement technique with resolving power R = lambda/Delta lambda up to 7500 for some science cases. Examples are the characterization of highly ionized gases in galaxy halos and within and around galaxy clusters, accretion onto supermassive black holes, stellar coronal mass ejections and coronal heating. Arcus, a recently proposed high-resolution x-ray and FUV grating spectrometer Probe class mission, exceeds current capabilities by far, with a minimum R of 2500 (similar to 3500 expected) and effective area up to 500 cm(2) in the 10-50 degrees A band, covered by the X-ray Spectrometer (XRS) instrument. The XRS relies on light-weight, high-efficiency, blazed and alignment-insensitive critical-angle transmission (CAT) gratings for dispersion and calls for hundreds of similar to 30 x 30 mm(2) gratings. Recent gratings have been fabricated from 200-mm silicon-on-insulator (SOI) wafers using commercial tools from the semiconductor and MEMS industries compatible with volume production. Previously we reported x-ray results from quasi-fully illuminated co-aligned CAT gratings showing record-high R up to 1.3x10(4) in 18th and 21st diffraction orders at Al-K (similar to 1.5 keV), and diffraction efficiency in agreement with synchrotron measurements and model predictions at O-K. We were recently able to chemically reduce the width of the freestanding, 200 nm-period, ultra-high aspect ratio CAT grating bars post-fabrication, and we report on the resulting increase in diffraction efficiency.

Recent X-ray studies of starburst galaxies have found that Charge eXchange (CX) commonly occurs between the outflowing hot plasma and cold gas, possibly from swept-up clouds. However, the total CX flux and the regions where CX occurs have been poorly understood. We present an analysis of the {\it XMM-Newton} observations of M82, a prototype starburst galaxy, aiming to investigate these key properties of the CX emisssion. We have used a blind source separation method in the image analysis with the CCD data which identified a component with the enhanced O-K lines expected from the CX process. Analyzing the RGS spectra from the region identified by the image analysis, we have detected a high forbidden-to-resonance ratio in the \ion{O}{7} He$\alpha$ triplet as well as several emission lines from K-shell transitions of C, N, and O enhanced in the CX process. The CX is less responsible for the emission line of Ne and Mg and the accurate estimation of the CX contribution is confirmed to be crucial in measuring chemical abundances. The temperature of the plasma as electron receiver in the CX process is significantly lower compared to that of the plasma components responsible for most of the X-rays. From the low temperature and an estimation of the CX emitting volume, we find that the CX primarily occurs in a limited region at the interface of the plasma and gas whose temperature rapidly decreases due to thermal conduction.

We make an in-depth analysis of different active galactic nuclei (AGN) jet models' signatures, inducing quiescence in galaxies with a halo mass of 1012 M circle dot. Three jet models, including cosmic-ray-dominant, hot thermal, and precessing kinetic jets, are studied at two energy flux levels each, compared to a jet-free, stellar feedback-only simulation. Each of our simulations is idealized isolated galaxy simulations with AGN jet powers that are constant in time and generated using GIZMO and with FIRE stellar feedback. We examine the distribution of Mg ii, O vi, and O viii ions, alongside gas temperature and density profiles. Low-energy ions, like Mg ii, concentrate in the interstellar medium (ISM), while higher energy ions, e.g., O viii, prevail at the AGN jet cocoon's edge. High-energy flux jets display an isotropic ion distribution with lower overall density. High-energy thermal or cosmic-ray jets pressurize at smaller radii, significantly suppressing core density. The cosmic-ray jet provides extra pressure support, extending cool and warm gas distribution. A break in the ion-to-mass ratio slope in O vi and O viii is demonstrated in the ISM-to-circumgalactic medium (CGM) transition (between 10 and 30 kpc), growing smoothly toward the CGM at greater distances.

Accurate atomic data and plasma models are essential for interpreting the upcoming high-quality spectra from missions like XRISM and Athena. Estimating physical quantities, like temperature, abundance, turbulence, and the resonance scattering factor, is highly dependent on the underlying atomic data. We use the AtomDB tool variableapec to estimate the impact of atomic data uncertainties in Einstein A coefficients, collisional rate coefficients, and the ionization and recombination rates of H-, He-, and Li-like iron in modeling the spectrum of Perseus observed by Hitomi. The best-fit temperatures, abundances, resonance scattering factors, and turbulence parameters including atomic data uncertainties vary by approximately 17%, 35%, 30%, and 3%, respectively, from the best-fit temperatures, abundances, RS factors, and turbulence parameters estimated without atomic data uncertainties. These indicate that approximately 32%, 35%, and 25% of the best-fit temperatures, abundances, and resonance scattering factors when including uncertainties lie outside the 3 σ error regions of their corresponding best-fit values computed with zero atomic data errors. Expanding the energy range to 1.8–20.0 keV shows less variability, with 26% of the abundances and 22% of the resonance scattering factors lying outside the 3 σ errors of the best-fit values. We also studied correlations between physical parameters and atomic rate uncertainties to identify key atomic quantities requiring precise lab measurements. We report negative correlations between the best-fit temperatures and the z (1s2s ^3 S _1 → 1s ^2 ) collisional rate coefficients, abundances and y (1s2p ^3 P _1 → 1s ^2 ) collisional rate coefficients, and abundances and z collisional rate coefficients, and a positive correlation between the resonance scattering factors and the w (1s2p ^1 P _1 → 1s ^2 ) collisional rate coefficients.

We present an in-depth analysis of the newly proposed correlation function in visibility space, between the E and B modes of linear polarization, hereafter the EB correlation, for a set of time-averaged general relativistic magnetohydrodynamical simulations compared with the phase map from different semianalytic models and the Event Horizon Telescope (EHT) 2017 data for M87*. We demonstrate that the phase map of time-averaged EB correlation contains novel information that might be linked to black hole (BH) spin, accretion state, and electron temperature. A detailed comparison with a semianalytic approach with different azimuthal expansion modes shows that to recover the morphology of real/imaginary part of the correlation function and its phase, we require higher orders of azimuthal modes. To extract the phase features, we use Zernike polynomial reconstruction developing an empirical metric to break degeneracies between models with different BH spins that are qualitatively similar. We use a set of geometrical ring models with various magnetic and velocity field morphologies, showing that both the image space and visibility-based EB -correlation morphologies in magnetically arrested disk simulations can be explained with simple fluid and magnetic field geometries as used in ring models. Standard and normal evolutions by contrast are harder to model, demonstrating that the simple fluid and magnetic field geometries of ring models are not sufficient to describe them owing to higher Faraday rotation depths. A qualitative comparison with the EHT data demonstrates that some of the features in the phase of EB correlation might be well explained by the current models for BH spins and electron temperatures, while others require larger theoretical surveys.

In an effort to measure electron-impact ionization (EII) cross-sections of He-like Fe24+ at the electron beam ion trap (EBIT) facility of the National Institute of Standards and Technology (NIST), we have experimentally determined the corrections to the nominal beam energy determined by the voltages applied to the EBIT. High-resolution X-ray spectra were recorded at nominal electron beam energies between 6660 eV and 6750 eV using X-ray microcalorimetry based upon an array of 192 transition-edge sensors (TES). A large-scale collisional-radiative simulation of the non-Maxwellian EBIT plasma using relevant atomic data calculated with Flexible Atomic Code allowed us to determine the space-charge correction due to the electron beam including the neutralization factor by the ion cloud of the EBIT.