Miracle-dz/UniFAR-FTUs huggingface dataset:
FREE–FREE EMISSION AND RADIO RECOMBINATION LINES FROM PHOTOEVAPORATING DISKS

Recent infrared observations have demonstrated that photoevaporation driven by high-energy photons from the central star contributes to the dispersal of protoplanetary disks. Here, we show that photoevaporative winds should produce a detectable free–free continuum emission given the range of stellar ionizing photons and X-ray luminosities inferred for young Sun-like stars. We point out that Very Large Array observations of the nearby disk around TW Hya might have already detected this emission at centimeter wavelengths and calculate the wind electron density and mass flow rate. We also estimate the intensities of H radio recombination lines tracing the wind and discuss which ones could be detected with current instrumentation. The detection and profiles of these recombination lines would unambiguously prove our inference of free–free emission from photoevaporating disks like TW Hya. In addition, radio/millimeter data can help constraining wind parameters such as temperature and electron density that are fundamental in measuring mass flow rates.
BaFe1.8Co0.2As2 thin film hybrid Josephson junctions

Josephson junctions with iron pnictides open the way for fundamental experiments on superconductivity in these materials and their application in superconducting devices. Here, we present hybrid Josephson junctions with a BaFe1.8Co0. 2As2 thin film electrode, an Au barrier, and a PbIn counter electrode. The junction shows resistively shunted junction-like current-voltage characteristics up to the critical temperature of the counter electrode of about 7.2 K. The temperature dependence of the critical current shows nearly linear behavior near TC. Well-pronounced Shapiro steps are observed at microwave frequencies of 10–18 GHz. Assuming an excess current of 200 μA at 4.2 K the effective ICRN product calculates to 7.9 μV.
Low-metallicity massive single stars with rotation. Evolutionary models applicable to I Zwicky 18

Massive rotating single stars with an initial metal composition appropriate for the dwarf galaxy I Zw 18 ([Fe/H]=$-$1.7) are modelled during hydrogen burning for initial masses of 9-300 M$_{\odot}$ and rotational velocities of 0-900 km s$^{-1}$. Internal mixing processes in these models were calibrated based on an observed sample of OB-type stars in the Magellanic Clouds. Even moderately fast rotators, which may be abundant at this metallicity, are found to undergo efficient mixing induced by rotation resulting in quasi chemically-homogeneous evolution. These homogeneously-evolving models reach effective temperatures of up to 90 kK during core hydrogen burning. This, together with their moderate mass-loss rates, make them Transparent Wind Ultraviolet INtense stars (TWUIN star), and their expected numbers might explain the observed HeII ionizing photon flux in I Zw 18 and other low-metallicity HeII galaxies. Our slowly rotating stars above $\sim$80 M$_{\odot}$ evolve into late B- to M-type supergiants during core hydrogen burning, with visual magnitudes up to 19$^{\mathrm{m}}$ at the distance of I Zw 18. Both types of stars, TWUIN stars and luminous late-type supergiants, are only predicted at low metallicity. Massive star evolution at low metallicity is shown to differ qualitatively from that in metal-rich environments. Our grid can be used to interpret observations of local star-forming dwarf galaxies and high-redshift galaxies, as well as the metal-poor components of our Milky Way and its globular clusters.
SIMULTANEOUS OBSERVATION OF WATER AND CLASS I METHANOL MASERS TOWARD CLASS II METHANOL MASER SOURCES

We present a simultaneous single-dish survey of 22 GHz water masers and 44 and 95 GHz class I methanol masers toward 77 6.7 GHz class II methanol maser sources, which were selected from the Arecibo methanol maser Galactic plane survey catalog. Water maser emission is detected in 39 (51%) sources, 15 of which are new detections. Methanol maser emission at 44 and 95 GHz is found in 25 (32%) and 19 (25%) sources, 21 and 13 of which, respectively, are newly detected. We find four high-velocity (>30 km s−1) water maser sources, including three dominant blue- or redshifted outflows. The 95 GHz masers always appear with 44 GHz maser emission. They are strongly correlated with 44 GHz masers in velocity, flux density, and luminosity, yet they are not correlated with either water or 6.7 GHz class II methanol masers. The average peak flux density ratio of 95 GHz masers to 44 GHz masers is close to unity, which is two times higher than previous estimates. The flux densities of class I methanol masers are more closely correlated with the associated Bolocam Galactic Plane Survey core mass than those of water masers or class II methanol masers. Using the large velocity gradient model and assuming unsaturated class I methanol maser emission, we derive the fractional abundance of methanol to be in the range 4.2 × 10−8–2.3 × 10−6, with a median value of 3.3 ± 2.7 × 10−7.
Representation of singular fields without asymptotic enrichment in the extended finite element method

In this paper, we replace the asymptotic enrichments around the crack tip in the extended finite element method (XFEM) with the semi‐analytical solution obtained by the scaled boundary finite element method (SBFEM). The proposed method does not require special numerical integration technique to compute the stiffness matrix, and it improves the capability of the XFEM to model cracks in homogeneous and/or heterogeneous materials without a priori knowledge of the asymptotic solutions. A Heaviside enrichment is used to represent the jump across the discontinuity surface. We call the method as the extended SBFEM. Numerical results presented for a few benchmark problems in the context of linear elastic fracture mechanics show that the proposed method yields accurate results with improved condition number. A simple code is annexed to compute the terms in the stiffness matrix, which can easily be integrated in any existing FEM/XFEM code. Copyright © 2013 John Wiley & Sons, Ltd.
Energy Transformation and the UAE Green Economy: Trade Exchange and Relations with Three Seas Initiative Countries

In 2015, on the initiative of Poland and Croatia, the Three Seas Initiative (3SI) was adopted, combining economic and political cooperation between 12 countries of Central and Eastern Europe, located between the three seas of the Adriatic, the Baltic, and the Black Sea. Since then, there has been a dynamic relationship between these countries and the United Arab Emirates. Consequently, most 3SI states have signed economic cooperation agreements, establishing the Joint Economic Committees (JEC). Therefore, this manuscript aims to answer the research question to what extent the visits at the highest level support the trade exchange between the United Arab Emirates (UAE) and the 3SI countries. Another question is, what are the cooperation prospects related to the energy transformation and initiatives on the green economy for sustainable development? To find the answer, the author implemented quantitative methods together with case studies. The results show that regular top-level visits support trade. At the same time, the study demonstrates a strategic potential for energy transformation.
AGN feedback: galactic-scale outflows driven by radiation pressure on dust

Galaxy-scale outows, which are thought to provide the link connecting the central black hole to its host galaxy, are now starting to be observed. However, the physical origin of the mechanism driving the observed outows, whether due to energy-driving or radiation-driving, is still debated; and in some cases, it is not clear whether the central source is an active galactic nucleus (AGN) or a nuclear starburst. Here we study the role of radiation pressure on dust in driving galactic-scale AGN outows, and analyse the dynamics of the outowing shell as a function of the underlying physical parameters. We show that high-velocity outows ( &1000 km/s) with large momentum ux ( & 10L=c) can be obtained, by taking into account the eects of radiation trapping. In particular, the high observed values of the momentum boosts can be reproduced, provided that the shell is initially optically thick to the reprocessed infrared radiation. Alternatively, the inferred measurements of the momentum ux may be signicantly biased by AGN variability. In this context, the observations of powerful outows on kiloparsec scales, with no or weak signs of ongoing nuclear activity at the present time, could be re-interpreted as relics of past AGN episodes.
ULTRA-HIGH ENERGY NEUTRINOS FROM GAMMA-RAY BURST AFTERGLOWS USING THE SWIFT-UVOT DATA

We consider a sample of 107 gamma-ray bursts (GRBs) for which early ultra-violet emission was measured by Swift and extrapolate the photon intensity to lower energies. Protons accelerated in the GRB jet may interact with such photons to produce charged pions and subsequently ultra high energy neutrinos ϵ &ngr; ≥ 10 16 ? > eV. We use simple energy conversion efficiency arguments to predict the maximal neutrino flux expected from each GRB. We estimate the neutrino detection rate at large area radio based neutrino detectors and conclude that the early afterglow neutrino emission is too weak to be detected even by next generation neutrino observatories.
Class I methanol masers in low-mass star formation regions

Abstract Four Class I maser sources were detected at 44, 84, and 95 GHz toward chemically rich outflows in the regions of low-mass star formation NGC 1333I4A, NGC 1333I2A, HH25, and L1157. One more maser was found at 36 GHz toward a similar outflow, NGC 2023. Flux densities of the newly detected masers are no more than 18 Jy, being much lower than those of strong masers in regions of high-mass star formation. The brightness temperatures of the strongest peaks in NGC 1333I4A, HH25, and L1157 at 44 GHz are higher than 2000 K, whereas that of the peak in NGC 1333I2A is only 176 K. However, a rotational diagram analysis showed that the latter source is also a maser. The main properties of the newly detected masers are similar to those of Class I methanol masers in regions of massive star formation. The former masers are likely to be an extension of the latter maser population toward low luminosities of both the masers and the corresponding YSOs.
β PICTORIS AND AB DORADUS MOVING GROUPS: LIKELY NEW LOW-MASS MEMBERS

We present results from our continuing program to identify new, low-mass, members of the nearby young moving groups (NYMGs) using a proper motion selection algorithm and various observational techniques. We have three goals: (1) to provide high priority targets for exoplanet searches by direct imaging, (2) to complete the census of the membership in the NYMGs down to ∼0.1 M☉, and thus (3) provide a well-characterized sample of nearby (median distances at least twice as close as the Taurus and Ophiuchus star-forming regions), young (8–50 Myr) stars for detailed study of their physical properties and multiplicity. Our program proceeds as follows: we apply the selection algorithm to a proper motion catalog where initial selection cuts of candidate members are based on the mean motion of known NYMG members and the proper motions and photometric distances of the candidates. NYMG membership is investigated further using possible signs of youth, including Hα emission and X-ray flux, and then verified through radial velocity measurements. We identify TYC 1766-1431-1 (M3), TYC 1208-468-1 and 2 (K3), TYC 7558-655-1 (K5), and PM I04439+3723W and E (M3) as likely members of the β Pictoris moving group (BPMG) and TYC 1741-2117-1N and S (K7), TYC 1752-63-1 (K7), TYC 523-573-1 (K7), and TYC 4943-192-1 (M0) as likely members of the AB Doradus moving group (ABDMG). We also rule out the membership of several BPMG and ABDMG candidates. To date our program has identified 16 new NYMG members of spectral type K3 or later.
The Relationship between the Need for Closure and Coronavirus Fear: The Mediating Effect of Beliefs in Conspiracy Theories about COVID-19

This study investigated the relationship between fear of the coronavirus, belief in COVID-19 conspiracy theories, and dimensions of the need for cognitive closure. As there is evidence of associations between these variables, we hypothesized that the relationship between the need for closure dimensions and coronavirus fear may be mediated by conspiracy beliefs about COVID-19. We analyzed the results from 380 individuals who completed online versions of three scales: the Fear of COVID-19 Scale, a short version of the Need for Closure Scale, and—designed for this study—the Conspiracy Theories about the Coronavirus Scale. The results showed that belief in COVID-19 conspiracy theories fully mediated the relationship between the fear of the coronavirus and avoidance of ambiguity, as well as closed-mindedness. The findings provided evidence that beliefs in conspiracy theories may play a significant role in reducing the level of coronavirus fear in people with high levels of these traits. In addition, a partial mediation between the fear of the coronavirus and the need for predictability was found. The limitations and implications of the research are discussed.
HOW ROCKY ARE THEY? THE COMPOSITION DISTRIBUTION OF KEPLER’S SUB-NEPTUNE PLANET CANDIDATES WITHIN 0.15 AU

The Kepler Mission has found thousands of planetary candidates with radii between 1 and 4 R ⨁ ? > . These planets have no analogues in our own solar system, providing an unprecedented opportunity to understand the range and distribution of planetary compositions allowed by planet formation and evolution. A precise mass measurement is usually required to constrain the possible composition of an individual super-Earth-sized planet, but these measurements are difficult and expensive to make for the majority of Kepler planet candidates (PCs). Fortunately, adopting a statistical approach helps us to address this question without them. In particular, we apply hierarchical Bayesian modeling to a subsample of Kepler PCs that is complete for P < 25 ? > days and R pl > 1.2 ? > R ⨁ ? > and draw upon interior structure models that yield radii largely independent of mass by accounting for the thermal evolution of a gaseous envelope around a rocky core. Assuming the envelope is dominated by hydrogen and helium, we present the current-day composition distribution of the sub-Neptune-sized planet population and find that H+He envelopes are most likely to be ∼1% of these planets’ total masses with an intrinsic scatter of ±0.5 dex. We address the gaseous/rocky transition and illustrate how our results do not result in a one-to-one relationship between mass and radius for this sub-Neptune population; accordingly, dynamical studies that wish to use Kepler data must adopt a probabilistic approach to accurately represent the range of possible masses at a given radius.
EVERY INTERACTING DOUBLE WHITE DWARF BINARY MAY MERGE

Interacting double white dwarf (WD) binaries can give rise to a wide variety of astrophysical outcomes ranging from faint thermonuclear and Type Ia supernovae to the formation of neutron stars and stably accreting AM Canum Venaticorum systems. One key factor affecting the final outcome is whether mass transfer remains dynamically stable or instead diverges, leading to the tidal disruption of the donor and the merger of the binary. It is typically thought that for low ratios of the donor mass to the accretor mass, mass transfer remains stable, especially if accretion occurs via a disk. In this Letter, we examine low mass ratio double WD binaries and find that the initial phase of hydrogen-rich mass transfer leads to a classical nova-like outburst on the accretor. Dynamical friction within the expanding nova shell shrinks the orbit and causes the mass transfer rate to increase dramatically above the accretor's Eddington limit, possibly resulting in a binary merger. If the binary survives the first hydrogen-rich nova outbursts, dynamical friction within the subsequent helium-powered nova shells pushes the system even more strongly toward merger. While further calculations are necessary to confirm this outcome for the entire range of binaries previously thought to be dynamically stable, it appears likely that most, if not all, interacting double WD binaries will merge during the course of their evolution.
NSCC—A NEW SCHEME OF CLASSIFICATION OF C-RICH STARS DEVISED FROM OPTICAL AND INFRARED OBSERVATIONS

A new classification system for carbon-rich stars is presented based on an analysis of 51 asymptotic giant branch carbon stars through the most relevant classifying indices available. The extension incorporated, which also represents the major advantage of this new system, is the combination of the usual optical indices that describe the photospheres of the objects, with new infrared ones, which allow an interpretation of the circumstellar environment of the carbon-rich stars. This new system is presented with the usual spectral subclasses and C2-, j-, MS-, and temperature indices, and also with the new SiC- (SiC/C.A. abundance estimation) and τ- (opacity) indices. The values for the infrared indices were carried out through a Monte Carlo simulation of the radiative transfer in the circumstellar envelopes of the stars. The full set of indices, when applied to our sample, resulted in a more efficient system of classification, since an examination in a wide spectral range allows us to obtain a complete scenario for carbon stars.
Resonance risk assessment method on a storage pump’s centrifugal impeller by considering the hydrodynamic damping ratio

How to accurately predict the resonance operating point and the corresponding vibrating amplitude of the underwater structures are of interest in the field of hydraulic machinery. In the present investigation, a resonance risk assessment method consisting of unsteady CFD, modal work approach, and harmonic response analysis is established, and an implementation is carried out on a centrifugal impeller of a storage pump. The simulation results (head, efficiency, and pressure pulsation) are carefully verified by comparing them with the experimental results, with relative deviations within 11%. Regarding the prototype pump, the amplitude of the pressure pulsation coefficient is almost identical to the model pump, with a relative deviation of 13.5%. It is found that the hydrodynamic damping ratio is gradually decreased if the operating flow rate deviates from the design one, based on the modal work approach. And then, the harmonic response is carried out on the prototype impeller, by setting the pressure pulsation as the initial excitation condition and considering the hydrodynamic damping ratio. Finally, the natural frequency, the resonance amplitude, and maximum equivalent stress are quantitatively determined, which proves that the resonance risk assessment method has the potential to judge the resonance operating point and destructiveness in practical engineering.
Finite size and intrinsic field effect on the polar-active properties of ferroelectric-semiconductor heterostructures

Using Landau-Ginzburg-Devonshire approach we calculated the equilibrium distributions of electric field, polarization and space charge in the ferroelectric-semiconductor heterostructures containing proper or incipient ferroelectric thin films. The role of the polarization gradient and intrinsic surface energy, interface dipoles and free charges on polarization dynamics are specifically explored. The intrinsic field effects, which originated at the ferroelectric-semiconductor interface, lead to the surface band bending and result into the formation of depletion space-charge layer near the semiconductor surface. During the local polarization reversal (caused by the electric field of the nanosized tip of the Scanning Probe Microscope) the thickness and charge of the interface layer drastically changes, in particular the sign of the screening carriers is determined by the polarization direction. Obtained analytical solutions could be extended to analyze polarization-mediated electronic transport.
Phase diagram of the fully frustrated transverse-field Ising model on the honeycomb lattice

Motivated by the current interest in the quantum dimer model on the triangular lattice, we investigate the phase diagram of the closely related fully frustrated transverse-field Ising model on the honeycomb lattice using classical and semiclassical approximations. We show that, in addition to the fully polarized phase at a large field, the classical model possesses a multitude of phases that break the translational symmetry which, in the dimer language, correspond to a plaquette phase and a columnar phase separated by an infinite cascade of mixed phases. The modification of the phase diagram by quantum fluctuations has been investigated in the context of linear spin-wave theory. The extrapolation of the semiclassical energies suggests that the plaquette phase extends down to zero field for spin 1/2, in agreement with the root 12 x root 12 phase of the quantum dimer model on the triangular lattice with only kinetic energy.
Mass transfer and magnetic braking in Sco X-1

Sco X-1 is a low-mass X-ray binary (LMXB) that has one of the most precisely determined set of binary parameters such as the mass accretion rate, companions mass ratio and the orbital period. For this system, as well as for a large fraction of other well-studied LMXBs, the observationally-inferred mass accretion rate is known to strongly exceed the theoretically expected mass transfer rate. We suggest that this discrepancy can be solved by applying a modified magnetic braking prescription, which accounts for increased wind mass loss in evolved stars compared to main sequence stars. Using our mass transfer framework based on {\tt MESA}, we explore a large range of binaries at the onset of the mass transfer. We identify the subset of binaries for which the mass transfer tracks cross the Sco X-1 values for the mass ratio and the orbital period. We confirm that no solution can be found for which the standard magnetic braking can provide the observed accretion rates, while wind-boosted magnetic braking can provide the observed accretion rates for many progenitor binaries that evolve to the observed orbital period and mass ratio.
The rate and latency of star formation in dense, massive clumps in the Milky Way

Newborn stars form within the localized, high density regions of molecular clouds. The sequence and rate at which stars form in dense clumps and the dependence on local and global environments are key factors in developing descriptions of stellar production in galaxies. We seek to observationally constrain the rate and latency of star formation in dense massive clumps that are distributed throughout the Galaxy and to compare these results to proposed prescriptions for stellar production. A sample of 24 micron-based Class~I protostars are linked to dust clumps that are embedded within molecular clouds selected from the APEX Telescope Large Area Survey of the Galaxy. We determine the fraction of star-forming clumps, f*, that imposes a constraint on the latency of star formation in units of a clump's lifetime. Protostellar masses are estimated from models of circumstellar environments of young stellar objects from which star formation rates are derived. Physical properties of the clumps are calculated from 870 micron dust continuum emission and NH_3 line emission. Linear correlations are identified between the star formation rate surface density, Sigma_{SFR}, and the quantities Sigma_{H2}/tau_{ff} and Sigma_{H2}/tau_{cross}, suggesting that star formation is regulated at the local scales of molecular clouds. The measured fraction of star forming clumps is 23%. Accounting for star formation within clumps that are excluded from our sample due to 24 micron saturation, this fraction can be as high as 31%. Dense, massive clumps form primarily low mass (< 1-2 msun) stars with emergent 24 micron fluxes below our sensitivity limit or are incapable of forming any stars for the initial 70% of their lifetimes. The low fraction of star forming clumps in the Galactic center relative to those located in the disk of the Milky Way is verified.