Miracle-dz/UniFAR-FTUs huggingface dataset:
The dependence of convective core overshooting on stellar mass

Convective core overshooting extends the main-sequence lifetime of a star. Evolutionary tracks computed with overshooting are quite different from those that use the classical Schwarzschild criterion, which leads to rather different predictions for the stellar properties. Attempts over the last two decades to calibrate the degree of overshooting with stellar mass using detached double-lined eclipsing binaries have been largely inconclusive, mainly due to a lack of suitable observational data. Here we revisit the question of a possible mass dependence of overshooting with a more complete sample of binaries, and examine any additional relation there might be with evolutionary state or metal abundance Z. We use a carefully selected sample of 33 double-lined eclipsing binaries strategically positioned in the H-R diagram, with accurate absolute dimensions and component masses ranging from 1.2 to 4.4 solar masses. We compare their measured properties with stellar evolution calculations to infer semi-empirical values of the overshooting parameter alpha(ov) for each star. Our models use the common prescription for the overshoot distance d(ov) = alpha(ov) Hp, where Hp is the pressure scale height at the edge of the convective core as given by the Schwarzschild criterion, and alpha(ov) is a free parameter. We find a relation between alpha(ov) and mass that is defined much more clearly than in previous work, and indicates a significant rise up to about 2 solar masses followed by little or no change beyond this mass. No appreciable dependence is seen with evolutionary state at a given mass, or with metallicity at a given mass despite the fact that the stars in our sample span a range of a factor of ten in [Fe/H], from -1.01 to +0.01.
Intrapixel effects of CCD and CMOS detectors

Intrapixel nonuniformity is known to exist in CCD and CMOS image sensors, though the effects in backside illuminated (BSI) CCDs are too small to be a concern for most astronomical observations. However, projects like the Large Synoptic Survey Telescope require precise knowledge of the detector characteristics, and intrapixel effects may need more attention. By scanning CCD and CMOS cameras with a small light spot (unresolved by the optics), we find in the images that the spot's flux, centroid displacement, and ellipticity vary periodically on the pixel scale in most cases. The amplitude of variation depends on not only the detector but also how well the spot is sampled by the pixels. With a spot radius of 2 pixels (encircling 80% energy) as measured, the flux and the ellipticity extracted from the BSI CCD camera vary by 0.2–0.3% (rms) and 0.005 (rms), respectively, while the deviation of the centroid position (rms ∼ 0.01 pixel) is not correlated with the pixels. The effects are more pronounced for the BSI CMOS camera and even worse for the frontside illuminated CMOS camera. The results suggest that a closer examination of the intrapixel effects is needed for precision astronomy.
Evolution of supermassive black hole binaries and tidal disruption rates in non-spherical galactic nuclei

Binary supermassive black holes (SMBH) are expected to form naturally during galaxy mergers. After the dynamical friction phase, when the two SMBHs become gravitationally bound to each other, and a brief stage of initial rapid hardening, the orbit gradually continues to shrink due to three-body interactions with stars that enter the loss cone of the binary. Using the stellar-dynamical Monte Carlo code Raga, we explore the co-evolution of the binary SMBH and the nuclear star cluster in this slow stage, for various combinations of parameters (geometry of the star cluster, primary/secondary SMBH mass, initial eccentricity, inclusion of stellar captures/tidal disruptions). We compare the rates of stellar captures in galactic nuclei containing a binary to those of galaxies with a single SMBH. At early times, the rates are substantially higher in the case of a binary SMBH, but subsequently they drop to lower levels. Only in triaxial systems both the binary hardening rates and the capture rates remain sufficiently high during the entire evolution. We find that the hardening rate is not influenced by star captures, nor does it depend on eccentricity; however, it is higher when the difference between the black hole masses is greater. We confirm that the eccentricity of the binary tends to grow, which may significantly shorten the coalescence time due to earlier onset of gravitational-wave emission. We also explore the properties of the orbits entering the loss cone, and demonstrate that it remains partially full throughout the evolution in the triaxial case, but significantly depleted in the axisymmetric case. Finally, we study the distribution of ejected hypervelocity stars and the corresponding mass deficits in the central parts of the galaxies hosting a binary, and argue that the missing mass is difficult to quantify observationally.
Scale-aware stereo direct visual odometry with online photometric calibration for agricultural environment

Vision-based localization and mapping for agricultural environment is challenging due to unstructured scene with less distinguishable landmarks and more repetitive textures, scale drift caused by wide and distant view, illumination variations and abrupt movements. To address these challenges, we propose a scale-aware stereo direct odometry with online photometric calibration for agricultural environment. We first propose a scale-aware stereo direct image alignment method to explicitly capture the scale at tracking stage. Then we optimize the scale and affine brightness parameters of stereo frames to keep the scale consistency in the sliding window. Furthermore, we incorporate online photometric calibration to resist illumination changes and exposure differences of image sequence. The proposed system achieves new state-of-the-art results on two public agricultural datasets, demonstrating its effectiveness in challenging agricultural environments. GRAPHICAL ABSTRACT
Phylogenomics of the family Lachesillidae (Insecta: Psocodea: Psocomorpha)

Lachesillidae is one of the largest families of bark lice and includes more than 420 described species, in 26 genera and three subfamilies. This family belongs in the suborder Psocomorpha, infraorder Homilopsocidea. The classification of Lachesillidae is based on male and female genital morphologies, but questions remain regarding the monophyly of the family and some of its genera. Here, we used whole genome and transcriptome data to generate a 2060 orthologous gene data matrix of 2,438,763 aligned bp and used these data to reconstruct the phylogenetic relationships of species of Lachesillidae and relatives. Taxon sampling included 24 species from Lachesillidae and 23 additional species belonging to related families from the infraorders Homilopsocidea and Caeciliusetae. Phylogenetic relationships reconstructed with maximum likelihood and coalescent‐based analyses indicated paraphyly of Lachesillidae, and monophyly of the tribe Graphocaeciliini and the genus Lachesilla were also never recovered. Instability was observed in the position of Eolachesilla chilensis, which was recovered either as sister to Elipsocidae or to Mesopsocidae species, so we cannot conclusively determine the position of this genus within the Homilopsocidea. Given our results, a reclassification is necessary, but more taxon sampling of other species in Mesopsocidae and Peripsocidae would be useful to add to a tree in future before proposing a new classification.
Next-to-next-to-leading-order ε expansion for a Fermi gas at infinite scattering length

We extend previous work on applying the $ϵ$ expansion to universal properties of a cold, dilute Fermi gas in the unitary regime of infinite scattering length. We compute the ratio $\ensuremath{\xi}=\ensuremath{\mu}∕{ϵ}_{\mathrm{F}}$ of chemical potential to ideal gas Fermi energy to next-to-next-to-leading-order (NNLO) in $ϵ=4\ensuremath{-}d$, where $d$ is the number of spatial dimensions. We also explore the nature of corrections from the order after NNLO.
A ray‐tracing model to account for off–great circle HF propagation over northerly paths

Off–great circle HF propagation effects are a common feature of the northerly ionosphere (i.e., the subauroral trough region, the auroral zone, and the polar cap). In addition to their importance in radiolocation applications where deviations from the great circle path may result in significant triangulation errors, they are also important in two other respects: (1) In systems employing directional antennas pointed along the great circle path, the signal quality may be degraded at times when propagation is via off–great circle propagation modes; and (2) the off–great circle propagation mechanisms may result in propagation at times when the signal frequency exceeds the maximum usable frequency along the great circle path. A ray‐tracing model covering the northerly ionosphere is described in this paper. The results obtained using the model are very reminiscent of the directional characteristics observed in various experimental measurement programs, and consequently, it is believed that the model may be employed to enable the nature of off–great circle propagation effects to be estimated for paths which were not subject to experimental investigation. Although it is not possible to predict individual off–great circle propagation events, it is possible to predict the periods during which large deviations are likely to occur and their magnitudes and directions.
CO Multi-line Imaging of Nearby Galaxies (COMING). III. Dynamical effect on molecular gas density and star formation in the barred spiral galaxy NGC 4303

We present the results of $^{12}\textrm{C}$$\textrm{O}$(J = 1–0) and $^{13}\textrm{C}$$\textrm{O}$(J = 1–0) simultaneous mappings toward the nearby barred spiral galaxy NGC 4303 as part of the CO Multi-line Imaging of Nearby Galaxies (COMING) project. Barred spiral galaxies often show lower star-formation efficiency (SFE) in their bar region compared to the spiral arms. In this paper, we examine the relation between the SFEs and the volume densities of molecular gas n(H2) in the eight different regions within the galactic disk with $\textrm{C}$$\textrm{O}$ data combined with archival far-ultraviolet and 24 μm data. We confirmed that SFE in the bar region is lower by 39% than that in the spiral arms. Moreover, velocity-alignment stacking analysis was performed for the spectra in the individual regions. Integrated intensity ratios of $^{12}\textrm{C}$$\textrm{O}$ to $^{13}\textrm{C}$$\textrm{O}$ (R12/13) ranging from 10 to 17 were the results of this stacking. Fixing a kinetic temperature of molecular gas, $n(\rm {H_2})$ was derived from R12/13 via non-local thermodynamic equilibrium (non-LTE) analysis. The density n(H2) in the bar is lower by 31%–37% than that in the arms and there is a rather tight positive correlation between SFEs and n(H2), with a correlation coefficient of ∼0.8. Furthermore, we found a dependence of $n(\rm {H}_2)$ on the velocity dispersion of inter-molecular clouds (ΔV/sin i). Specifically, n(H2) increases as ΔV/sin i increases when ΔV/sin i < 100 km s−1. On the other hand, n(H2) decreases as ΔV/sin i increases when ΔV/sin i > 100 km s−1. These relations indicate that the variations of SFE could be caused by the volume densities of molecular gas, and the volume densities could be governed by the dynamical influence such as cloud–cloud collisions, shear, and enhanced inner-cloud turbulence.
H-, He-like recombination spectra – III. n-changing collisions in highly excited Rydberg states and their impact on the radio, IR, and optical recombination lines

At intermediate to high densities, electron (de-)excitation collisions are the dominant process for populating or depopulating high Rydberg states. In particular, the accurate knowledge of the energy changing (n-changing) collisional rates is determinant for predicting the radio recombination spectra of gaseous nebula. The different data sets present in the literature come either from impact parameter calculations or semi-empirical fits and the rate coefficients agree within a factor of 2. We show in this paper that these uncertainties cause errors lower than 5 per cent in the emission of radio recombination lines of most ionized plasmas of typical nebulae. However, in special circumstances where the transitions between Rydberg levels are amplified by maser effects, the errors can increase up to 20 per cent. We present simulations of the optical depth and Hnα line emission of active galactic nuclei broad-line regions and the Orion Nebula Blister to showcase our findings.
Effect of Viscosity on Long Gravity Waves

The effect of viscosity is examined on long gravity waves of small but finite amplitude. The reductive perturbation method combined with the usual boundary layer theory reveals that the inviscid Korteweg-de Vries equation is not affected by the viscosity if O(α -5 )< R , where R is the Reynolds number and α(≪1) the wavenumber. For O(α -1 )< R ≤O(α -5 ), the effect of viscosity modifies the Korteweg-de Vries equation and yields new types of equation. On the other hand, for R <O(α -1 ), the complex phase velocity becomes purely imaginary and the free surface is found to be governed by a nonlinear diffusion equation which was first obtained by Nakaya.
Effects of high-energy proton irradiation on the superconducting properties of Fe(Se,Te) thin films

In this paper we explore the effects of 3.5 MeV proton irradiation on Fe(Se,Te) thin films grown on CaF2. In particular, we carry out an experimental investigation with different irradiation fluences up to 7.30 · 1016 cm−2 and different proton implantation depths, in order to clarify whether and to what extent the critical current is enhanced or suppressed, what are the effects of irradiation on the critical temperature, resistivity, and critical magnetic fields, and finally what is the role played by the substrate in this context. We find that the effect of irradiation on superconducting properties is generally small compared to the case of other iron-based superconductors. The irradiation effect is more evident on the critical current density Jc, while it is minor on the transition temperature Tc, normal state resistivity ρ, and on the upper critical field Hc2 up to the highest fluences explored in this work. In more detail, our analysis shows that when protons implant in the substrate far from the superconducting film, the critical current can be enhanced up to 50% of the pristine value at 7 T and 12 K; meanwhile, there is no appreciable effect on critical temperature and critical fields together with a slight decrease in resistivity. On the contrary, when the implantation layer is closer to the film–substrate interface, both critical current and temperature show a decrease accompanied by an enhancement of the resistivity and lattice strain. This result evidences that possible modifications induced by irradiation in the substrate may affect the superconducting properties of the film via lattice strain. The robustness of the Fe(Se,Te) system to irradiation-induced damage makes it a promising compound for the fabrication of magnets in high-energy accelerators.
Critical Phenomena in Gravitational Collapse: The Studies So Far

Studies of black hole formation from gravitational collapse have revealed interesting non-linear phenomena at the threshold of black hole formation. In particular, in 1993 Choptuik studied the collapse of a massless scalar field with spherical symmetry and found some behaviour, which is quite similar to the critical phenomena well-known in Statistical Mechanics and Quantum Field Theory. Universality and echoing of the critical solution and power-law scaling of the black hole masses have given rise to the name Critical Phenomena in Gravitational Collapse. Choptuik's results were soon confirmed both numerically and semi-analytically, and have extended to various other matter fields. In this paper, we shall give a brief introduction to this fascinating and relatively new area, and provide an updated publication list. An analytical "toy" model of critical collapse is presented, and some current investigations are given.
The kinematics of σ-drop bulges from spectral synthesis modelling of a hydrodynamical simulation

A minimum in stellar velocity dispersion is often observed in the central regions of disc galaxies. To investigate the origin of this feature, known as a {\sigma}-drop, we analyse the stellar kinematics of a high-resolution N-body + smooth particle hydrodynamical simulation, which models the secular evolution of an unbarred disc galaxy. We compared the intrinsic mass-weighted kinematics to the recovered luminosity-weighted ones. The latter were obtained by analysing synthetic spectra produced by a new code, SYNTRA, that generates synthetic spectra by assigning a stellar population synthesis model to each star particle based on its age and metallicity. The kinematics were derived from the synthetic spectra as in real spectra to mimic the kinematic analysis of real galaxies. We found that the recovered luminosity-weighted kinematics in the centre of the simulated galaxy are biased to higher rotation velocities and lower velocity dispersions due to the presence of young stars in a thin and kinematically cool disc, and are ultimately responsible for the {\sigma}-drop.
Hydrodynamic construction of the electromagnetic field

We present an alternative Eulerian hydrodynamic model for the electromagnetic field in which the discrete vector indices in Maxwell's equations are replaced by continuous angular freedoms, and develop the corresponding Lagrangian picture in which the fluid particles have rotational and translational freedoms. This enables us to extend to the electromagnetic field the exact method of state construction proposed previously for spin 0 systems, in which the time-dependent wavefunction is computed from a single-valued continuum of deterministic trajectories where two spacetime points are linked by at most a single orbit. The deduction of Maxwell's equations from continuum mechanics is achieved by generalizing the spin 0 theory to a general Riemannian manifold from which the electromagnetic construction is extracted as a special case. In particular, the flat-space Maxwell equations are represented as a curved-space Schrödinger equation for a massive system. The Lorentz covariance of the Eulerian field theory is obtained from the non-covariant Lagrangian-coordinate model as a kind of collective effect. The method makes manifest the electromagnetic analogue of the quantum potential that is tacit in Maxwell's equations. This implies a novel definition of the ‘classical limit’ of Maxwell's equations that differs from geometrical optics. It is shown that Maxwell's equations may be obtained by canonical quantization of the classical model. Using the classical trajectories a novel expression is derived for the propagator of the electromagnetic field in the Eulerian picture. The trajectory and propagator methods of solution are illustrated for the case of a light wave.
Moringa oleifera seed extract-mediated flocculation as an efficient method for harvesting Chlorella lewinii biomass

The aim of this research was to investigate the potentials of harvesting Chlorella lewinii through flocculation by Moringa oleifera seed extract. Water, ethanol, and sodium chloride solution were used to extract flocculating agents from both whole and de-fatted Moringa oleifera seeds and their ability to flocculate C. lewinii cells were evaluated. The effects of extracting solvents, extract concentration, incubation period and culture age on flocculation efficiency were investigated. The lipid contents of the biomass harvested by flocculation using M. oleifera seed extract were compared with those harvested by centrifugation. The results showed that 1M sodium chloride solution was the most effective solvent for extracting M. oleifera active ingredient. The optimum extract concentration was 600±0.10 mg/L with approximately 60±0.46 % efficiency, while the optimum length of period for incubating a mixture of cell culture and seed extract was 80±0.26 min. Defatted Moringa oleifera seed extract was more efficient than whole seed extract with an efficiency of 50%. The percentage lipid content of biomass harvested by centrifuge and moringa extracts decreased in the following order: Centrifugation-(22.55%) > de-fatted seed extract (16.63%) > whole seed extract (14.42%). These results indicate that M. oleifera seed extract is a reliable method of harvesting microalgae biomass.
History state formalism for Dirac’s theory

We propose a history state formalism for a Dirac particle. By introducing a reference quantum clock system it is first shown that Dirac's equation can be derived by enforcing a timeless Wheeler-DeWitt-like equation for a global state. The Hilbert space of the whole system constitutes a unitary representation of the Lorentz group with respect to a properly defined invariant product, and the proper normalization of global states directly ensures standard Dirac's norm. Moreover, by introducing a second quantum clock, the previous invariant product emerges naturally from a generalized continuity equation. The invariant parameter $\tau$ associated with this second clock labels history states for different particles, yielding an observable evolution in the case of an hypothetical superposition of different masses. Analytical expressions for both space-time density and electron-time entanglement are provided for two particular families of electron's states, the former including Pryce localized particles.
Continuous-time limit of topological quantum walks

We derive the continuous-time limit of discrete quantum walks with topological phases. We show the existence of a continuous-time limit that preserves their topological phases. We consider both simple-step and splitstep walks, and derive analytically equations of motion governing their behavior. We obtain simple analytical solutions showing the existence of bound states at the boundary of two phases, and solve the equations of motion numerically in the bulk.
Exact eigenstates of tight-binding Hamiltonians on the Penrose tiling

We investigate exact eigenstates of tight-binding models on the planar rhombic Penrose tiling. We consider a vertex model with hopping along the edges and the diagonals of the rhombi. For the wave functions, we employ an ansatz, first introduced by Sutherland, which is based on the arrow decoration that encodes the matching rules of the tiling. Exact eigenstates are constructed for particular values of the hopping parameters and the eigenenergy. By a generalized ansatz that exploits the inflation symmetry of the tiling, we show that the corresponding eigenenergies are infinitely degenerate. Generalizations and applications to other systems are outlined.