Miracle-dz/UniFAR-FTUs huggingface dataset:
Galactic Archeology with 4MOST

Abstract 4MOST is a new wide-field, high-multiplex spectroscopic survey facility for the VISTA telescope of ESO. Starting in 2022, 4MOST will deploy 2400 fibres in a 4.1 square degree field-of-view using a positioner based on the tilting spine principle. In this contribution we give an outline of the major science goals we wish to achieve with 4MOST in the area of Galactic Archeology. The 4MOST Galactic Archeology surveys have been designed to address long-standing and far-reaching problems in Galactic science. They are focused on four major themes: 1) Near-field cosmology tests, 2) Chemo-dynamical characterisation of the major Milky Way stellar components, 3) The Galactic Halo and beyond, and 4) Discovery and characterisation of extremely metal-poor stars. In addition to a top-level description of the Galactic surveys we provide information about how the community will be able to join 4MOST via a call for Public Spectroscopic Surveys that ESO will launch.
DETECTING ILLUMINATION CHANGES IN THREE-DIMENSIONAL SCENES

Craven & Foster (1992) found that observers could readily distinguish illuminant chromaticity changes from surface color changes in Mondrian scenes. Changes in illuminant did not affect the photoreceptor excitation ratios across edges; they concluded that the visual system detected surface changes as ratio constancy violations. In 3D scenes, with multiple illuminants and matte surfaces at many orientations, changes in the positions or chromaticities of light sources need not leave edge ratios invariant. We examine how well observers can distinguish changes in the direction of a collimated light source in rendered 3D scenes viewed binocularly. Observers were asked to distinguish illumination changes from matched changes in achromatic surface colors. We find that, in 3D scenes with non- homogeneous illumination, observers can discriminate very small changes (at 2-4 degrees, d’ exceeds 1) in the spatial distribution of light from matched surface changes despite the lack of ratio constancy between adjacent surfaces.
Redshift Evolution of the Black Hole Merger Rate from Globular Clusters

As the sensitivity of current and future gravitational-wave detectors improves, it will become possible to measure the evolution of the binary black hole merger rate with redshift. Here, we combine detailed fits to state-of-the-art dynamical models of binary black hole formation in dense star clusters with a cosmological model of cluster formation across cosmic time. We find a typical merger rate of 14 Gpc−3 yr−1 in the local universe, with a reasonable range of 4–18 Gpc−3 yr−1, depending on the rate of cluster disruption and the cluster initial mass function. This rate increases by a factor of 6 to redshift z = 2.7 before declining at higher redshifts. We compare the merger rate from binaries produced in clusters to similar estimates from isolated binaries and triples in galactic fields, and discuss various ways that these different formation channels could add up to the current merger rate observed by the Laser Interferometer Gravitational-Wave Observatory/Virgo.
On the Evolution of a Plain Zero Net Mass Flux Jet Injected in a Quiescent Medium

A plain zero net mass flux (ZNMF) jet injected in a quiescent medium is presently investigated numerically employing the unsteady Reynolds averaged Navier Stokes simulation approach. The flow features encompassing centerline mean velocity evolution, self-similar mean velocity distribution, jet momentum flux and stagnation point location are studied at different jet Strouhal and Reynolds numbers. The present investigation shows that the far field behavior of a plain ZNMF jet somewhat resembles the steady plain turbulent jets. Accordingly, the centerline mean velocity varies on the basis of a power law decaying profile and the cross stream mean velocity distribution illustrates an approximately self-similarity condition. However, it is demonstrated that the present ZNMF jet momentum flux is not constant with the streamwise coordinate contrary to a steady turbulent jet. Also, the stagnation point location is shown to reach its maximum at around t/T = 0.8 and the maximum location strongly depends on the jet Strouhal number.
J0023+0307: A Mega Metal-poor Dwarf Star from SDSS/BOSS

Only a handful of stars have been identified with an iron abundance [Fe/H] < −5, and only one at [Fe/H] < −7. These stars have very large carbon-to-iron ratios, with ∼ 7.0, most likely due to fallback in core-collapse supernovae, which makes their total metallicity Z much higher than their iron abundances. The failure to find population III stars, those with no metals, has been interpreted, with support from theoretical modeling, as the result of a top-heavy initial mass function. With zero or very low metal abundance limiting radiative cooling, the formation of low-mass stars could be inhibited. Currently, the star SDSS J1029+1729 sets the potential metallicity threshold for the formation of low-mass stars at . In our quest to push down the metallicity threshold we have identified SDSS J0023+0307, a primitive star with Teff = 6188 ± 84 K, and , an upper limit [Fe/H] < −6.6, and a carbon abundance A(C) < 6.3. We find J0023+0307 to be one of the two most iron-poor stars known, and it exhibits less carbon that most of the stars at [Fe/H] < −5.
Relative-observer definition of the Simon tensor

The definition of the Simon tensor, originally given only in Kerr spacetime and associated with the static family of observers, is generalized to any spacetime and to any possible observer family. Such generalization is obtained by a standard ‘3 + 1’ splitting of the Bianchi identities, which are rewritten here as a ‘balance equation’ between various spatial fields, associated with the kinematical properties of the observer congruence and representing the spacetime curvature.
The ROSAT North Ecliptic Pole Survey: The X-Ray Catalog

The sky around the north ecliptic pole (NEP), at α(J2000.0) = 18h00m00s, δ(J2000.0) = +66°33′39′′, has the deepest exposure of the entire ROSAT All-Sky Survey (RASS). The NEP is an undistinguished region of moderate Galactic latitude, b = 29. °8, and hence suitable for compiling statistical samples of both Galactic and extragalactic objects. We have made such a compilation in the 80.6 deg2 region surrounding the NEP. Our sample fully exploits the properties of the RASS, since the only criteria for inclusion are source position and significance, and it yields the deepest large solid angle contiguous sample of X-ray sources to date. We find 442 unique sources above a flux limit ~2 × 10-14 ergs cm-2 s-1 in the 0.5-2.0 keV band. In this paper we present the X-ray properties of these sources as determined from the RASS. These include positions, fluxes, spectral information in the form of hardness ratios, and angular sizes. Since we have performed a comprehensive optical identification program we also present the average X-ray properties of classes of objects typical of the X-ray sky at these flux levels. We discuss the use of the RASS to find clusters of galaxies based on their X-ray properties alone.
Albedos, Equilibrium Temperatures, and Surface Temperatures of Habitable Planets

The potential habitability of known exoplanets is often categorized by a nominal equilibrium temperature assuming a Bond albedo of either ∼0.3, similar to Earth, or 0. As an indicator of habitability, this leaves much to be desired, because albedos of other planets can be very different, and because surface temperature exceeds equilibrium temperature due to the atmospheric greenhouse effect. We use an ensemble of general circulation model simulations to show that for a range of habitable planets, much of the variability of Bond albedo, equilibrium temperature and even surface temperature can be predicted with useful accuracy from incident stellar flux and stellar temperature, two known parameters for every confirmed exoplanet. Earth’s Bond albedo is near the minimum possible for habitable planets orbiting G stars, because of increasing contributions from clouds and sea ice/snow at higher and lower instellations, respectively. For habitable M star planets, Bond albedo is usually lower than Earth’s because of near-IR H2O absorption, except at high instellation where clouds are important. We apply relationships derived from this behavior to several known exoplanets to derive zeroth-order estimates of their potential habitability. More expansive multivariate statistical models that include currently non-observable parameters show that greenhouse gas variations produce significant variance in albedo and surface temperature, while increasing length of day and land fraction decrease surface temperature; insights for other parameters are limited by our sampling. We discuss how emerging information from global climate models might resolve some degeneracies and help focus scarce observing resources on the most promising planets.
Nonlocality free wirings and the distinguishability between Bell boxes

Bell nonlocality can be formulated in terms of a resource theory with local-hidden variable models as resourceless objects. Two such theories are known, one built upon local operations assisted by shared randomness (LOSRs) and the other one allowing, in addition, for prior-to-input classical communication. We show that prior communication, although unable to create nonlocality, leads to wirings not only beyond LOSRs but also not contained in a much broader class of (nonlocality-generating) global wirings. Technically, this is shown by proving that it can improve the statistical distinguishability between Bell correlations optimised over all fixed measurement choices. This has implications in nonlocality quantification, and leads us to a natural universal definition of Bell nonlocality measures. To end up with, we also consider the statistical strength of nonlocality proofs. We point out some issues of its standard definition in the resource-theoretic operational framework, and suggest simple fixes for them. Our findings reveal non-trivial features of the geometry of the set of wirings and may have implications in the operational distinguishability of nonlocal behaviors.
Exterior spacetime of relativistic stars in scalar-Gauss-Bonnet gravity

The spacetime around compact objects is an excellent place to study gravity in the strong, nonlinear, dynamical regime where solar system tests cannot account for the effects of large curvature. Understanding the dynamics of this spacetime is important for testing theories of gravity and probing a regime which has not yet been studied with observations. In this paper, we construct an analytical solution for the exterior spacetime of a neutron star in scalar-Gauss-Bonnet gravity that is independent of the equation of state chosen. The aim is to provide a metric that can be used to probe the strong-field regime near a neutron star and create predictions that can be compared with future observations to place possible constraints on the theory. In addition to constructing the metric, we examine a number of physical systems in order to see what deviations exist between our spacetime and that of general relativity. We find these deviations to be small and of higher post-Newtonian order than previous results using black hole solutions. The metric derived here can be used to further the study of scalar-Gauss-Bonnet gravity in the strong field, and allow for constraints on corrections to general relativity with future observations.
Structural, magnetic, and electrical properties of single-crystalline La 1 − x Sr x MnO 3 ( 0.4 x 0.85 )

We report on structural, magnetic, and electrical properties of Sr-doped ${\mathrm{LaMnO}}_{3}$ single crystals for doping levels $0.4l~xl~0.85. $ The complex structural and magnetic phase diagram can only be explained assuming significant contributions from the orbital degrees of freedom. Close to $x=0.6$ a ferromagnetic metal is followed by an antiferromagnetic metallic phase below 200 K. This antiferromagnetic metallic phase exists in a monoclinic crystallographic structure. Following theoretical predictions this metallic antiferromagnet is expected to reveal an ${(x}^{2}\ensuremath{-}{y}^{2})$-type orbital order. For higher Sr concentrations an antiferromagnetic insulator is established below room temperature.
A study of the fine‐scale motions of incompressible time‐developing mixing layers

The geometry of dissipating motions in direct numerical simulations (DNS) of the incompressible mixing layer is examined. All nine partial derivatives of the velocity field are determined at every grid point in the flow, and various invariants and related quantities are computed from the velocity gradient tensor. Motions characterized by high rates of kinetic energy dissipation and high enstrophy density are of particular interest. Scatter plots of the invariants are mapped out and interesting and unexpected patterns are seen. Depending on initial conditions, each type of shear layer produces its own characteristic scatter plot. In order to provide more detailed information on the distribution of invariants at intermediate and large scales, scatter plots are replaced with more useful number density contour plots. These essentially represent the unnormalized joint probability density function of the two invariants being cross‐plotted. Plane mixing layers at the same Reynolds number, but with laminar and tu.
Clinical simulation in nursing in the light of experiential learning: systematic review

Objective: to identify the effectiveness of clinical simulations based on experiential learning as a theoretical-methodological framework in comparison with different pedagogical strategies in nursing education. Method: systematic review carried out using the sources: Medical Literature Analysis and Retrieval System Online; Scopus, Web of Science, Latin American and Caribbean Literature in Health Sciences, Cumulative Index to Nursing and Allied Health Literature, and Educational Resources Information Center. Instruments were used to evaluate the methodological path. Results: 268 studies were identified and four made up the sample. Experiential learning in the simulation was compared to case study; expository class; problem solving and simulation without framework. The studies obtained good quality by the JBI instrument and moderate by the Medical Education Research Study Quality Instrument. Conclusion: experiential learning is effective for simulation-based nursing education. abstract conceptualization (conceptualizing); and active experimentation (applying) (3) .
Nonaxisymmetric Neutral Modes in Rotating Relativistic Stars

We study nonaxisymmetric perturbations of rotating relativistic stars modeled as perfect-fluid equilibria. Instability to a mode with angular dependence exp (imϕ) sets in when the frequency of the mode vanishes. The locations of these zero-frequency modes along sequences of rotating stars are computed for the first time in the framework of general relativity. We consider models of uniformly rotating stars with polytropic equations of state, finding that the relativistic models are unstable to nonaxisymmetric modes at significantly smaller values of rotation than in the Newtonian limit. Most strikingly, the m = 2 bar mode can become unstable even for soft polytropes of index N ≤ 1.3, while in Newtonian theory it becomes unstable only for stiff polytropes of index N ≤ 0.808. If rapidly rotating neutron stars are formed by the accretion-induced collapse of white dwarfs, instability associated with these nonaxisymmetric, gravitational-wave driven modes may set an upper limit on neutron-star rotation. Consideration is restricted to perturbations that correspond to polar perturbations of a spherical star. A study of axial perturbations is in progress.
The Interplay between Radiation Pressure and the Photoelectric Instability in Optically Thin Disks of Gas and Dust

In optically thin disks, dust grains are photoelectrically stripped of electrons by starlight, heating nearby gas and possibly creating a dust clumping instability—the photoelectric instability (PeI)—that significantly alters global disk structure. In the current work, we use the Pencil Code to perform the first numerical models of the PeI that include stellar radiation pressure on dust grains in order to explore the parameter regime in which the instability operates. In some models with low gas and dust surface densities, we see a variety of dust structures, including sharp concentric rings. In the most gas- and dust-rich models, nonaxisymmetric clumps, arcs, and spiral arms emerge that represent dust surface density enhancements of factors of ∼5–20. In one high gas surface density model, we include a large, low-order gas viscosity and find that it observably smooths the structures that form in the gas and dust, suggesting that resolved images of a given disk may be useful for deriving constraints on the effective viscosity of its gas. Our models show that radiation pressure does not preclude the formation of complex structure from the PeI, but the qualitative manifestation of the PeI depends strongly on the parameters of the system. The PeI may provide an explanation for unusual disk morphologies, such as the moving blobs of the AU Mic disk, the asymmetric dust distribution of the 49 Ceti disk, and the rings and arcs found in the HD 141569A disk.
Quantitative principles for precise engineering of sensitivity in carbon-based electrochemical sensors

A major practical barrier for implementing carbon-based electrode arrays with high device-packing density is to ensure large, predictable, and homogeneous sensitivities across the array. Overcoming this barrier depends on quantitative models to predict electrode sensitivity from its material structure. However, such models are currently lacking. Here, we show that the sensitivity of multilayer graphene electrodes increases linearly with the average point defect density, whereas it is unaffected by line defects or oxygen-containing groups. These quantitative relationships persist until the electrode material transitions to a fully disordered sp2 carbon, where sensitivity declines sharply. We show that our results generalize to a variety of graphene production methods and use them to derive a predictive model that guides nano-engineering graphene structure for optimum sensitivity. Our approach achieves reproducible fabrication of miniaturized sensors with extraordinarily higher sensitivity than conventional material. These results lay the foundation for new integrated electrochemical sensor arrays based on nano-engineered graphene.
Reinforcement of interfacial superconductivity in a Bi2Te3/Fe1+yTe heterostructure under hydrostatic pressure

We investigate the hydrostatic pressure dependence of interfacial superconductivity occurring at the atomically sharp interface between two non-superconducting materials: the topological insulator (TI) Bi2Te3 and the parent compound Fe1+yTe of the chalcogenide iron based superconductors. Under pressure, a significant increase in the superconducting transition temperature Tc is observed. We trace the pressure dependence of a superconducting twin gap structure by Andreev reflection point contact spectroscopy (PCARS), which shows that a large superconducting gap associated with the interfacial superconductivity increases along with Tc. A second smaller gap, which is attributed to proximity-induced superconductivity in the TI layer, increases first, but then reaches a maximum and appears to be gradually suppressed at higher pressure. We interpret our data in the context of a pressure-induced doping effect of the interface, in which charge is transferred from the TI layer to the interface and the interfacial superconductivity is enhanced. This demonstrates the important role of the TI in the interfacial superconductivity mechanism.
Density Wave Probes Cuprate Quantum Phase Transition

In cuprate materials, the strong correlations in proximity to the antiferromagnetic Mott insulating state give rise to an array of unconventional phenomena beyond high temperature superconductivity. Developing a complete description of the ground state evolution is crucial to decoding the complex phase diagram. Here we use the structure of broken translational symmetry, namely $d$-form factor charge modulations in (Bi,Pb)$_2$(Sr,La)$_2$CuO$_{6+\delta}$, as a probe of the ground state reorganization which occurs at the transition from truncated Fermi arcs to a large Fermi surface. We use real space imaging of local electronic inhomogeneity as a tool to access a range of dopings within each sample, and we firmly establish the spectral gap $\Delta$ as a proxy for local hole doping. From the $\Delta$-dependence of the charge modulation wavevector, we discover a commensurate to incommensurate transition that is coincident with the Fermi surface transition from arcs to large hole pocket, demonstrating the qualitatively distinct nature of the electronic correlations governing the two sides of this quantum phase transition. Furthermore, the doping dependence of the incommensurate wavevector on the overdoped side is at odds with a simple Fermi surface driven instability.
An investigation of four chemically peculiar stars with photometric periods below 12 h

We present an investigation of three chemically peculiar (CP) stars and one CP star candidate that exhibit photometric periods below 12 h. New spectroscopic observations have been acquired that confirm the peculiar nature of all objects. HD 77013 and HD 81076 are classical CP1 (Am) stars, HD 67983 is a marginal CP1 (Am:) star and HD 98000 is a CP2 (Ap) star. We have procured observations from the ASAS-3 and SuperWASP archives and obtained additional photometry in order to verify the results from the sky survey data. We have derived astrophysical parameters and investigated the positions of our target stars in the MBol versus log Teff diagram, from which information on evolutionary status has been derived. We present period analyses and discuss each object in detail. From the available data, we propose pulsational variability as the underlying mechanism for the variability in HD 67983, HD 77013 and HD 81076, which offer the opportunity to study the interaction of atomic diffusion and pulsation. HD 67983 and HD 77013 exhibit multiperiodic variability in the. Doradus frequency realm; HD 81076 is a d Scuti star. The CP2 star HD 98000 exhibits monoperiodic variability with a frequency of f approximate to 2.148 cycles d(-1) (P approximate to 0.466 d), which we interpret as the rotational period. If this assumption is correct, HD 98000 is the alpha(2) Canum Venaticorum variable with the shortest period hitherto observed and thus a very interesting object that might help to investigate the influence of rotational mixing on chemical peculiarities.
Identifiability, Improper Priors, and Gibbs Sampling for Generalized Linear Models

Markov chain Monte Carlo algorithms are widely used in the fitting of generalized linear models (GLMs). Such model fitting is somewhat of an art form, requiring suitable trickery and tuning to obtain results in which one can have confidence. A wide range of practical issues arise. The focus here is on parameter identifiability and posterior propriety. In particular, we clarify that nonidentifiability arises for usual GLMs and discuss its implications for simulation-based model fitting. Because often some part of the prior specification is vague, we consider whether the resulting posterior is proper, providing rather general and easily checked results for GLMs. We also show that if a Gibbs sampler is run with an improper posterior, then it may be possible to use the output to obtain meaningful inference for certain model unknowns.