Miracle-dz/UniFAR-FTUs huggingface dataset:
Stochastic phenomena of synchronization in ensembles of mean-field coupled limit cycle oscillators with two native frequencies

We study effects of independent white noise on synchronization phenomena in ensembles of coupled limit cycle oscillators with different native frequencies. We consider a simple model where the ensemble consists of two inter-connected clusters with own native frequencies and mean-field couplings are introduced between intra- and inter-clusters. Taking advantage of the nonlinear mean-field coupling concept together with the law of large numbers valid in the thermodynamic limit, we employ a nonlinear Fokker-Planck equation approach that turns out to be a noise level-free analysis, to analytically derive the time evolution of the order parameters. Showing the occurrence of bifurcations from chaotic attractors in the deterministic limit to limit cycle ones with increasing noise intensity, we confirm the occurrence of nonequilibrium phase transitions including inter-cluster synchronization induced by external noise.
Photometric properties of the Local Volume dwarf galaxies

We present surface photometry and metallicity measurements for 104 nearby dwarf galaxies imaged with the Advanced Camera for Surveys and Wide Field and Planetary Camera 2 aboard the Hubble Space Telescope. In addition, we carried out photometry for 26 galaxies of the sample and for Sextans B on images of the Sloan Digital Sky Survey. Our sample comprises dwarf spheroidal, irregular and transition type galaxies located within ∼10 Mpc in the field and in nearby groups: M81, Centaurus A, Sculptor, and Canes Venatici I cloud. It is found that the early-type galaxies have on average higher metallicity at a given luminosity in comparison to the late-type objects. Dwarf galaxies with MB ≥ −12 ÷ −13 m deviate toward larger scale lengths from the scale length – luminosity relation common for spiral galaxies, h ∝ L 0.5 B . The following correlations between fundamental parameters of the galaxies are consistent with expectations if there is pronounced gas-loss through galactic winds: 1) between the luminosity of early-type dwarf galaxies and the mean metallicity of constituent red giant branch stars, Z ∼ L 0.4 , 2) between mean surface brightness within the 25 m /⊓ ′′ isophote and the corresponding absolute magnitude in the V and I bands, SB25 ∼ 0.3M25, and 3) between the central surface brightness (or effective surface brightness) and integrated absolute magnitude of galaxies in the V and I bands, SB0 ∼ 0.5ML, SBe ∼ 0.5Me. The knowledge of basic photometric parameters for a large sample of dwarf galaxies is essential for a better understanding of their evolution.
Dynamical corrections to spin-wave excitations in quantum wells due to Coulomb interactions and magnetic ions

We have measured dispersions of spin-flip waves and spin-flip single-particle excitations of a spin polarized two-dimensional electron gas in a CdMnTe quantum well using resonant Raman scattering. We find the energy of the spin-flip wave to be below the spin-flip single particle excitation continuum, a contradiction to the theory of spin waves in diluted magnetic semiconductors put forth in [Phys. Rev. B 70, 045205 (2004)]. We show that the inclusion of terms accounting for the Coulomb interaction between carriers in the spin wave propagator leads to an agreement with our experimental results. The dominant Coulomb contribution leads to an overall red shift of the mixed electron-Mn spin modes while the dynamical coupling between Mn ions results in a small blue shift. We provide a simulated model system which shows the reverse situation but at an extremely large magnetic field.
A 3.2 nW Current-Starved Voltage Controlled Ring Oscillator for Low Power Applications

—An integrated 3.2 nW subthreshold 21-stage ring oscillator with a frequency of 9.25 kHz was designed for a wake-up receiver. The gain and the number of stages for the voltage controlled oscillator determined the frequency. In addition, a 5-stage VCO was designed and manufactured as a PCB to show that the oscillator can operate in the subthreshold region.
Probing dark energy and neutrino mass from upcoming lensing experiments of CMB and galaxies

We discuss the synergy of the cosmic shear and CMB lensing experiments to simultaneously constrain the neutrino mass and dark energy properties. Taking fully account of the CMB lensing, cosmic shear, CMB anisotropies, and their cross correlation signals, we clarify a role of each signal, and investigate the extent to which the upcoming observations by a high-angular resolution experiment of CMB and deep galaxy imaging survey can tightly constrain the neutrino mass and dark energy equation-of-state parameters. Including the primary CMB information as a prior cosmological information, the Fisher analysis reveals that the time varying equation-of-state parameters, given by w(a) = w0+wa(1−a), can be tightly constrained with the accuracies of 5% for w0 and 15% for wa, which are comparable to or even better than those of the stage-III type surveys neglecting the effect of massive neutrinos. In other words, including the neutrino mass in the parameter estimation would not drastically alter the figure-of-Merit estimates of dark energy parameters from the weak lensing measurements. For the neutrino mass, a clear signal for total neutrino mass with ∼ 0.1 eV can be detected with ∼ 2-σ significance. The robustness and sensitivity of these results are checked in detail by allowing the setup of cosmic shear experiment to vary as a function of observation time or exposure time, showing that the improvement of the constraints very weakly depends on the survey parameters, and the results mentioned above are nearly optimal for the dark energy parameters and the neutrino mass.
Gravitational dynamics in Bose Einstein condensates

Analogue models for gravity intend to provide a framework where matter and gravity, as well as their intertwined dynamics, emerge from degrees of freedom that have a priori nothing to do with what we call gravity or matter. Bose-Einstein condensates (BEC) are a natural example of an analogue model since one can identify matter propagating on a (pseudo-Riemannian) metric with collective excitations above the condensate of atoms. However, until now, a description of the ``analogue gravitational dynamics'' for such model was missing. We show here that in a BEC system with massive quasiparticles, the gravitational dynamics can be encoded in a modified (semiclassical) Poisson equation. In particular, gravity is of extreme short range (characterized by the healing length) and the cosmological constant appears from the noncondensed fraction of atoms in the quasiparticle vacuum. While some of these features make the analogue gravitational dynamics of our BEC system quite different from standard Newtonian gravity, we nonetheless show that it can be used to draw some interesting lessons about ``emergent gravity'' scenarios.
Effects of strain on electronic properties of graphene

We present first-principles calculations of electronic properties of graphene under uniaxial and isotropic strains, respectively. The semimetallic nature is shown to persist up to a very large uniaxial strain of 30% except a very narrow strain range where a tiny energy gap opens. As the uniaxial strain increases along a certain direction, the Fermi velocity parallel to it decreases quickly and vanishes eventually, whereas the Fermi velocity perpendicular to it increases by as much as 25%. Thus, the low energy properties with small uniaxial strains can be described by the generalized Weyl's equation while massless and massive electrons coexist with large ones. The work function is also predicted to increase substantially as both the uniaxial and isotropic strain increases. Hence, the homogeneous strain in graphene can be regarded as the effective electronic scalar potential.
The gamma-ray luminosity function of millisecond pulsars and implications for the GeV excess

It has been proposed that a large population of unresolved millisecond pulsars (MSPs) could potentially account for the excess of GeV-scale gamma-rays observed from the region surrounding the Galactic Center. The viability of this scenario depends critically on the gamma-ray luminosity function of this source population, which determines how many MSPs Fermi should have already detected as resolved point sources. In this paper, we revisit the gamma-ray luminosity function of MSPs, without relying on uncertain distance measurements. Our determination, based on a comparison of models with the observed characteristics of the MSP population, suggests that Fermi should have already detected a significant number of sources associated with such a hypothesized Inner Galaxy population. We cannot rule out a scenario in which the MSPs residing near the Galactic Center are systematically less luminous than those present in the Galactic Plane or within globular clusters.
ON THE ORIGIN OF MASS SEGREGATION IN NGC 3603

We present deep Hubble Space Telescope/Wide Field and Planetary Camera 2 photometry of the young HD 97950 star cluster in the giant H ii region NGC 3603. The data were obtained in 1997 and 2007 permitting us to derive membership based on proper motions of the stars. Our data are consistent with an age of 1 Myr for the HD 97950 cluster. A possible age spread, if present in the cluster, appears to be small. The global slope of the incompleteness-corrected mass function for member stars within 60″ is Γ = −0.88 ± 0.15, which is flatter than the value of a Salpeter slope of −1.35. The radially varying mass function shows pronounced mass segregation ranging from slopes of −0.26 ± 0.32 in the inner 5″ to −0.94 ± 0.36 in the outermost annulus (40″–60″). Stars more massive than 50 M☉ are found only in the cluster center. The Λ minimum spanning tree technique confirms significant mass segregation down to 30 M☉. The dependence of Λ on mass, i.e., that high-mass stars are more segregated than low-mass stars, and the (weak) dependence of the velocity dispersion on stellar mass might imply that the mass segregation is dynamical in origin. While primordial segregation cannot be excluded, the properties of the mass segregation indicate that dynamical mass segregation may have been the dominant process for segregation of high-mass stars.
MUSE sneaks a peek at extreme ram-pressure stripping events - I. A kinematic study of the archetypal galaxy ESO137-001

We present Multi Unit Spectroscopic Explorer (MUSE) observations of ESO137−001, a spiral galaxy infalling towards the centre of the massive Norma cluster at z ∼ 0.0162. During the high-velocity encounter of ESO137−001 with the intracluster medium, a dramatic ram-pressure stripping event gives rise to an extended gaseous tail, traced by our MUSE observations to >30 kpc from the galaxy centre. By studying the Hα surface brightness and kinematics in tandem with the stellar velocity field, we conclude that ram pressure has completely removed the interstellar medium from the outer disc, while the primary tail is still fed by gas from the inner regions. Gravitational interactions do not appear to be a primary mechanism for gas removal. The stripped gas retains the imprint of the disc rotational velocity to ∼20 kpc downstream, without a significant gradient along the tail, which suggests that ESO137−001 is fast moving along a radial orbit in the plane of the sky. Conversely, beyond ∼20 kpc, a greater degree of turbulence is seen, with velocity dispersion up to ≳100 km s−1. For a model-dependent infall velocity of vinf ∼ 3000 km s−1, we conclude that the transition from laminar to turbulent flow in the tail occurs on time-scales ≥6.5 Myr. Our work demonstrates the terrific potential of MUSE for detailed studies of how ram-pressure stripping operates on small scales, providing a deep understanding of how galaxies interact with the dense plasma of the cluster environment.
The deuterium abundance in the local interstellar medium

As the Galaxy evolves, the abundance of deuterium in the interstellar medium (ISM) decreases from its primordial value: deuterium is ‘astrated’. The deuterium astration factor f D, the ratio of the primordial D abundance (the D to H ratio by number) to the ISM D abundance, is determined by the competition between stellar destruction and infall, providing a constraint on models of the chemical evolution of the Galaxy. Although conventional wisdom suggests that the local ISM (i.e. within ∼1–2 kpc of the Sun) should be well mixed and homogenized on time-scales short compared to the chemical evolution time-scale, the data reveal gas-phase variations in the deuterium, iron and other metal abundances as large as factors of ∼4–5 or more, complicating the estimate of the ‘true’ ISM D abundance and of the deuterium astration factor. Here, assuming that the variations in the observationally inferred ISM D abundances result entirely from the depletion of D on to dust, rather than from unmixed accretion of nearly primordial material, a model-independent, Bayesian approach is used to determine the undepleted abundance of deuterium in the ISM (or a lower limit to it). We find the best estimate for the undepleted, ISM deuterium abundance to be (D/H)ISM ≥ (2.0 ± 0.1) × 10 −5 . T his result is used to provide an estimate of (or an upper bound to) the deuterium astration factor, fD ≡ (D/H)P/(D/H)ISM ≤ 1.4 ± 0.1.
Optical design of the TolTEC millimeter-wave camera

TolTEC is a new camera being built for the 50-meter Large Millimeter-wave Telescope (LMT) in Puebla, Mexico to survey distant galaxies and star-forming regions in the Milky Way. The optical design simultaneously couples the field of view onto focal planes at 150, 220, and 280 GHz. The optical design and detector properties, as well as a data-driven model of the atmospheric emission of the LMT site, inform the sensitivity model of the integrated instrument. This model is used to optimize the instrument design, and to calculate the mapping speed as an early forecast of the science reach of the instrument.
Finite element setting for fluid flow simulations with natural enforcement of capillary effects

Capillary phenomena are involved in many industrial processes, especially those dealing with composite manufacturing. However, their modelling is still challenging. Therefore, a finite element setting is proposed to better investigate this complex issue. The variational formulation of a liquid-air Stokes system is established, while the solid substrate is described through boundary conditions. Expressing the weak form of Laplace's law over liquid-air, liquid-solid and air-solid interfaces, leads to a natural enforcement of the mechanical equilibrium over the wetting line, without imposing explicitly the contact angle itself. The mechanical problem is discretized by using finite elements, linear both in velocity and pressure, stabilized with a variational multiscale method, including the possibility of enrichment of the pressure space. The moving interface is captured by a Level-Set methodology, combined with a mesh adaptation technique with respect to both pressure and level-set fields. Our methodology can simulate capillary-driven flows in 2D and 3D with the desired precision: droplet spreading, droplet coalescence, capillary rise. In each case, the equilibrium state expected in terms of velocity, pressure and contact angle is reached.
Parallel-leaky capacitance equivalent circuit model for MgO magnetic tunnel junctions

The capacitance of MgO based magnetic tunnel junctions (MTJs) has been observed to be magnetic field dependent. We propose an equivalent circuit for the MTJs with a parallel-leaky capacitance (Cl) across the series combination of geometric and interfacial capacitance. The analysis of junctions with different tunneling magnetoresistance values suggests higher Cl for low TMR junctions. Using Cole-Cole plots the capacitive nature of MTJs is manifested. Fitting with Maxwell-Wagner capacitance model validates the RC parallel network model for MTJs and the extracted field dependent parameters match with the experimental values.
Cosmic ray-driven galactic winds: streaming or diffusion?

Cosmic rays (CRs) have recently re-emerged as attractive candidates for mediating feedback in galaxies because of their long cooling timescales. They can have energy densities comparable to the thermal gas, but do not suffer catastrophic cooling losses. Recent simulations have shown that the momentum and energy deposited by CRs moving with respect to the ambient medium can drive galactic winds. However, simulations are hampered by our ignorance of the details of CR transport. Two key limits previously considered model CR transport as a purely diffusive process (with a constant diffusion coefficient) and as an advective streaming process. With a series of GADGET simulations, we compare and contrast the results of these different assumptions. In idealised three-dimensional galaxy formation models, we show that these two cases result in significant differences for the galactic wind mass loss rates and star formation suppression in dwarf galaxies with halo masses $M\approx10^{10}\,\textrm{M}_\odot$: diffusive CR transport results in more than ten times larger mass loss rates compared to CR streaming models. We demonstrate that this is largely due to the excitation of Alfven waves during the CR streaming process that drains energy from the CR population to the thermal gas, which is subsequently radiated away. By contrast, CR diffusion conserves the CR energy in the absence of adiabatic changes and if CRs are efficiently scattered by Alfven waves that are propagating up the CR gradient. Moreover, because pressure gradients are preserved by CR streaming, but not diffusion, the two can have a significantly different dynamical evolution regardless of this energy exchange. In particular, the constant diffusion coefficients usually assumed can lead to unphysically high CR fluxes.
Lorentz-violating extension of the spin-one Duffin–Kemmer–Petiau equation

We investigate the breaking of Lorentz symmetry caused by the inclusion of an external four-vector via a Chern–Simons-like term in the Duffin–Kemmer–Petiau Lagrangian for massless and massive spin-one fields. The resulting equations of motion lead to the appearance of birefringence, where the corresponding photons are split into two propagation modes. We discuss the gauge invariance of the extended Lagrangian. Throughout the paper, we utilize projection operators to reduce the wave functions to their physical components, and we provide many new properties of these projection operators.
mapping build-up area density using normalized difference built-up index (ndbi) and urban index (ui) wetland in the city banjarmasin

Density and undeveloped land can be identified using digital transformation through remote sensing data. This study aims to map the distribution of building densities with the Normalized Difference Built-Up Index (NDBI) and Urban Index (UI), analyze the comparison of building densities of the NDBI and UI methods, and analyze the relationship between the transformation of NDBI and UI on building densities in Banjarmasin City. The data used to obtain building density image Landsat 8 Oli Tirs. The method used to separate the built area and non-building area using digital classification. The area was developed from the results of the multispectral classification filtered with NDBI and UI transformation for the classification of the building density level. The results of this study indicate that building density has a positive relationship with the transformation of NDBI and UI because the high building density in the transformation of NDBI and UI has a high value. Non-built area and constructed land shows an NDBI accuracy of 91.4505% and 92.5359% accuracy of UI, there is a difference of 1.0854% greater accuracy UI. Overall accuracy exceeding 80% indicates very high accuracy for building density mapping.
Dynamical Monte Carlo Simulations of 3-D Galactic Systems in Axisymmetric and Triaxial Potentials

Abstract We describe the dynamical behavior of isolated old ( ⩾ 1Gyr) objects-like Neutron Stars (NSs). These objects are evolved under smooth, time-independent, gravitational potentials, axisymmetric and with a triaxial dark halo. We analysed the geometry of the dynamics and applied the Poincaré section for comparing the influence of different birth velocities. The inspection of the maximal asymptotic Lyapunov (λ) exponent shows that dynamical behaviors of the selected orbits are nearly the same as the regular orbits with 2-DOF, both in axisymmetric and triaxial when (ϕ, qz )= (0,0). Conversely, a few chaotic trajectories are found with a rotated triaxial halo when (ϕ, qz )= (90, 1.5). The tube orbits preserve direction of their circulation around either the long or short axis as appeared in the triaxial potential, even when every initial condition leads to different orientations. The Poincaré section shows that there are 2-D invariant tori and invariant curves (islands) around stable periodic orbits that bound to the surface of 3-D tori. The regularity of several prototypical orbits offer the means to identify the phase-space regions with localized motions and to determine their environment in different models, because they can occupy significant parts of phase-space depending on the potential. This is of particular importance in Galactic Dynamics.
The role of molecular gas in galaxy transition in compact groups

Compact groups (CGs) provide an environment in which interactions between galaxies and with the intra-group medium enable and accelerate galaxy transitions from actively star forming to quiescent. Galaxies in transition from active to quiescent can be selected, by their infrared (IR) colors, as canyon or infrared transition zone (IRTZ) galaxies. We used a sample of CG galaxies with IR data from the Wide Field Infrared Survey Explorer (WISE) allowing us to calculate the stellar mass and star formation rate (SFR) for each galaxy. Furthermore, we present new CO(1-0) data for 27 galaxies and collect data from the literature to calculate the molecular gas mass for a total sample of 130 galaxies. This data set allows us to study the difference in the molecular gas fraction (Mmol/Mstar) and star formation efficiency (SFE=SFR/Mmol) between active, quiescent, and transitioning (i.e., canyon and IRTZ) galaxies. We find that transitioning galaxies have a mean molecular gas fraction and a mean SFE that are significantly lower than those of actively star-forming galaxies. The molecular gas fraction is higher than that of quiescent galaxies, whereas the SFE is similar. These results indicate that the transition from actively star-forming to quiescent in CG galaxies goes along with a loss of molecular gas, possibly due to tidal forces exerted from the neighboring galaxies or a decrease in the gas density. In addition, the remaining molecular gas loses its ability to form stars efficiently, possibly owing to turbulence perturbing the gas, as seen in other, well-studied examples such as Stephan's Quintet and HCG~57. Thus, the amount and properties of molecular gas play a crucial role in the environmentally driven transition of galaxies from actively star forming to quiescent.