ShantanuT01/DACTYL-Pretraining huggingface dataset:
Context. The prototype of Polar Ring Galaxies NGC 4650A contains two main structural components, a central spheroid, which is the host galaxy, and an extended polar disk. Both photometric and kinematic studies revealed that these two components co-exist on two different planes within the central regions of the galaxy. Aims. The aim of this work is to study the spectroscopic and kinematic properties of the host galaxy and the polar disk in the central regions of NGC 4650A by disentangling their contributions to the observed galaxy spectrum.   Methods. We applied the spectral decomposition technique introduced in previous works to long-slit spectroscopic observations in the CaII triplet region. We focused the analysis along the PA = 152 that corresponds to the photometric minor axis of the host galaxy, where the superimposition of the two components is more relevant and the spectral decomposition is necessary. We aim to disentangle the stars that move in the equatorial plane of the host galaxy from those that move in the meridan plane, which is along the polar disk.   Results. We successfully disentangled the spectra of the two structural components of NGC 4650A and measured their line-of-sight velocity and velocity dispersion profiles, and the stellar content along PA = 152. The host galaxy shows significant rotation along its photometric minor axis, indicating that the gravitational potential is not axisymmetric. The polar disk shows a kinematic decoupling: the inner regions counter-rotating with respect the outer-regions and the host spheroid. This suggests a complex formation history for the polar disk, characterised by mass accretion with decoupled angular momenta.
A Fokker action for post-Minkowski approximation with the first post-Newtonian correction is introduced in our previous paper, and a solution for the helically symmetric circular orbit is obtained. We present supplemental results for the circular solution of two unequal mass point-particles. Circular solutions for selected mass ratios are found numerically, and analytic formulas in the extreme mass ratio limit are derived. The leading terms of the analytic formulas agree with the first post-Newtonian formulas in this limit.
Continuous variables multipartite entanglement is a key resource for quantum technologies. This works considers the multipartite entanglement generated in separated spatial modes of the same light beam by three different parametric sources: a standard $\chi^{(2)}$ medium pumped by two pumps, a single-pump nonlinear photonic crystal, and a doubly pumped nonlinear photonic crystal. These sources have in common the coexistence of several concurrent nonlinear processes in the same medium, which allows the generation of non-standard 3 and 4-mode couplings. We test the genuine nature of the multipartite entangled states thereby generated in a common framework, using both criteria based on proper bounds for the variances of nonlocal observables and on the positive partial transpose criterion. The relative simplicity of these states allows a (hopefully) useful comparison of the different inseparability tests.
In this work we use a mapping technique to derive in the context of a constituent gluon model an effective Hamiltonian that involves explicit gluon degrees of freedom. We study glueballs with two gluons using the Fock-Tani formalism. In the present work we consider two possibilities for $0^{++}$: (i) as a pure $s\bar{s}$ and calculate, in the context of a quark interchange picture, the cross-section; (ii) as a glueball where a new calculation for this cross-section is made, in the context of the constituent gluon model, with gluon interchange.
On the basis of relativistic mean field calculations, we predict that the spin-orbit splitting of $p_{3/2}$ and $p_{1/2}$ neutron orbits depends sensitively on the magnitude of the proton density near the center of the nucleus, and in particular on the occupation of $s_{1/2}$ proton orbits. We focus on two exotic nuclei, $^{46}$Ar and $^{206}$Hg, in which the presence of a pair of $s_{1/2}$ proton holes is predicted to cause the splitting between the $p_{3/2}$ and $p_{1/2}$ neutron orbits near the Fermi surface to be much smaller than in the nearby doubly-magic nuclei $^{48}$Ca and $^{208}$Pb. We note that these two exotic nuclei depart from the long-standing paradigm of a central potential proportional to the ground state baryon density and a spin-orbit potential proportional to the derivative of the central potential.
We present an analysis of the relationship between molecular gas and current star formation rate surface density at sub-kpc and kpc scales in a sample of 14 nearby star-forming galaxies. Measuring the relationship in the bright, high molecular gas surface density ($\Shtwo\gtrsim$20 \msunpc) regions of the disks to minimize the contribution from diffuse extended emission, we find an approximately linear relation between molecular gas and star formation rate surface density, $\nmol\sim0.96\pm0.16$, with a molecular gas depletion time $\tdep\sim2.30\pm1.32$ Gyr. We show that, in the molecular regions of our galaxies there are no clear correlations between \tdep\ and the free-fall and effective Jeans dynamical times throughout the sample. We do not find strong trends in the power-law index of the spatially resolved molecular gas star formation law or the molecular gas depletion time across the range of galactic stellar masses sampled (\mstar $\sim$$10^{9.7}-10^{11.5}$ \msun). There is a trend, however, in global measurements that is particularly marked for low mass galaxies. We suggest this trend is probably due to the low surface brightness CO, and it is likely associated with changes in CO-to-H2 conversion factor.
In this paper we are interested in the following fourth order eigenvalue problem coming from the buckling of thin films on liquid substrates: \begin{equation*}   \begin{cases}   \Delta^2 u+ \kappa^2 u=-\lambda \Delta u &\text{in } B_1,\newline   u=\partial_r u= 0 &\text{on } \partial B_1,   \end{cases} \end{equation*} where $B_1$ is the unit ball in $\mathbb{R}^N$.   When $\kappa > 0$ is small, we show that the first eigenvalue is simple and the first eigenfunction, which gives the shape of the film for small displacements, is positive. However, when $\kappa$ increases, we establish that the first eigenvalue is not always simple and the first eigenfunction may change sign. More precisely, for any $\kappa \in (0,+\infty)$, we give the exact multiplicity of the first eigenvalue and the number of nodal regions of the first eigenfunction.
Outbursts of the black hole (BH) X-ray binaries are dramatic events occurring in our Galaxy approximately once a year. They are detected by the X-ray telescopes and often monitored at longer wavelengths. We analyse the X-ray and optical/infrared (OIR) light curves of the BH binary XTE J1550-564 during the 2000 outburst. By using the observed extreme colours as well as the characteristic decay time-scales of the OIR and X-ray light curves, we put strong constraints on the extinction towards the source. We accurately separate the contributions to the OIR flux of the irradiated accretion disc and a non-thermal component. We show that the OIR non-thermal component appears during the X-ray state transitions both during the rising and the decaying part of the outburst at nearly the same X-ray hardness but at luminosities differing by a factor of 3. The line marking the quenching/recovery of the non-thermal component at the X-ray hardness-flux diagram seems to coincide with the "jet line" that marks the presence of the compact radio jet. The inferred spectral shape and the evolution of the non-thermal component during the outburst, however, are not consistent with the jet origin, but are naturally explained in terms of the hybrid hot flow scenario, where non-thermal electrons emit synchrotron radiation in the OIR band. This implies a close, possibly causal connection between the presence of the hot flow and the compact jet. We find that the non-thermal component is hardening during the hard state at the decaying stage of the outburst, which indicates that the acceleration efficiency is a steep function of radius at low accretion rate.
Agekyan lambda-factor that accounts for the effect of multiple distant encounters with large impact factors is used for the first time to compute the diffusion coefficients in the velocity space of a stellar system. It is shown that in this case the cumulative effect - the total contribution of distant encounters to the change in the velocity of the test star - is finite, and the logarithmic divergence inherent to the classical description disappears, as also was earlier noted by Kandrup (1981). At the same time, the formulas for the diffusion coefficients, as before, contain the logarithm of the ratio of two independent scale factors that fully characterize the state of the stellar system: the average interparticle distance and the impact parameter of a close encounter. However, the physical meaning of this factor is no longer associated with the classical logarithmic divergence.
There is a strong degeneracy between the luminosity distance ($D_L$) and the observer viewing angle ($\theta_{\rm obs}$; hereafter viewing angle) of the gravitational wave (GW) source with an electromagnetic counterpart, GW170817. Here, for the first time, we present independent constraints on $\theta_{\rm obs} = 32.5 ^{\circ +11.7}_{-9.7}$ from broad-band photometry of the kilonova (kN) AT2017gfo associated with GW170817. These constraints are consistent with independent results presented in the literature using the associated gamma ray burst GRB170817A. Combining the constraints on $\theta_{\rm obs}$ with the GW data, we find an improvement of 24$\%$ on $H_0$. The observer angle constraints are insensitive to other model parameters, e.g. the ejecta mass, half-opening angle of the lanthanide-rich region and the temperature. A broad wavelength coverage extending to the near infrared is helpful to robustly constrain $\theta_{\rm obs}$. While the improvement on $H_0$ presented here is smaller than the one from high angular resolution imaging of the radio counterpart of GW170817, kN observations are significantly more feasible at the typical distances of such events from current and future LIGO-Virgo Collaboration observing runs ($D_L \sim 100$ Mpc). Our results are insensitive to the assumption on the peculiar velocity of the kN host galaxy.
We present the simplest model to which one can apply the supersymmetric Hubbard operators recently introduced. For the atomic model, $H=-E_d X_{00}$, where $X_{00} = |0><0|$ is a Hubbard operator and $E_d$ is the energy of the localized spin level, we show how one can develop exact solutions for the entropy and heat capacity as a function of temperature. With this gold standard we are able to develop a controlled approximation scheme to field theoretically treat the susy approximation at the level of mean field + gaussian corrections and test its accuracy against the widely used slave boson and slave fermion approximations. We find that in addition to slave boson and slave fermion solutions, a new class of solutions exists in the physical case Q = 1, N = 2 which can be properly treated by neither previously existing approach. The phase diagram generated by the mean field saddle-point bears a superficial resemblance to the V-shaped phase diagram common to systems close to a quantum critical point and may provide a natural starting point for investigations of strongly correlated models capturing this physics.
Considering that a position measurement can effectively involve a momentum-dependent shift and rescaling of the "true" space-time coordinates, we construct a set of effective space-time coordinates which are naturally non-commutative. They lead to a minimum length and are shown to be related to Snyder's coordinates and the five-dimensional formulation of Deformed Special Relativity. This effective approach then provides a natural physical interpretation for both the extra fifth dimension and the deformed momenta appearing in this context.
We prove a version of the BKK theorem for the ring of conditions of a spherical homogeneous space $G/H$. We also introduce the notion of ring of complete intersections, firstly for a spherical homogeneous space and secondly for an arbitrary variety. Similarly to the ring of conditions of the torus, the ring of complete intersections of $G/H$ admits a description in terms of volumes of polytopes.
We calculate the quantum corrections of the thermodynamic quantities of a system of confined Bosons at finite temperature. Systematically quantum corrections are written in a series of $\hbar$, which is convergent when $kT$ is much larger than the spacing between energy levels of the system. We apply this method to calculate analytically the thermodynamic potential of a weakly interacting Bose-gas confined in 3-d harmonic oscillator potential. For large number of particles, quantum corrections become small, and contribute to the finite size corrections to scaling.
Recent advances in quantum technologies are rapidly stimulating the building of quantum networks. With the parallel development of multiple physical platforms and different types of encodings, a challenge for present and future networks is to uphold a heterogeneous structure for full functionality and therefore support modular systems that are not necessarily compatible with one another. Central to this endeavor is the capability to distribute and interconnect optical entangled states relying on different discrete and continuous quantum variables. Here we report an entanglement swapping protocol connecting such entangled states. We generate single-photon entanglement and hybrid entanglement between particle-like and wave-like optical qubits, and then demonstrate the heralded creation of hybrid entanglement at a distance by using a specific Bell-state measurement. This ability opens up the prospect of connecting heterogeneous nodes of a network, with the promise of increased integration and novel functionalities.
We present high resolution numerical simulations of the colliding wind system $\eta$ Carinae, showing accretion onto the secondary star close to periastron passage. Our hydrodynamical simulations include self gravity and radiative cooling. The smooth stellar winds collide and develop instabilities, mainly the non-linear thin shell instability, and form filaments and clumps. We find that a few days before periastron passage the dense filaments and clumps flow towards the secondary as a result of its gravitational attraction, and reach the zone where we inject the secondary wind. We run our simulations for the conventional stellar masses, $M_1=120 ~\rm{M_\odot}$ and $M_2=30 ~\rm{M_\odot}$, and for a high mass model, $M_1=170 ~\rm{M_\odot}$ and $M_2=80 ~\rm{M_\odot}$, that was proposed to better fit the history of giant eruptions. As expected, the simulations results show that the accretion processes is more pronounced for a more massive secondary star.
The largest temperature anisotropy in the cosmic microwave background (CMB) is the dipole. The simplest interpretation of the dipole is that it is due to our motion with respect to the rest frame of the CMB. As well as creating the $\ell$=1 mode of the CMB sky, this motion affects all astrophysical observations by modulating and aberrating sources across the sky. It can be seen in galaxy clustering, and in principle its time derivative through a dipole-shaped acceleration pattern in quasar positions. Additionally, the dipole modulates the CMB temperature anisotropies with the same frequency dependence as the thermal Sunyaev-Zeldovich (tSZ) effect and so these modulated CMB anisotropies can be extracted from the tSZ maps produced by Planck. Unfortunately, this measurement cannot determine if the dipole is due to our motion, but it does provide an independent measure of the dipole and a validation of the y maps. This measurement, and a description of the first-order terms of the CMB dipole, are outlined here.
Temporal action segmentation approaches have been very successful recently. However, annotating videos with frame-wise labels to train such models is very expensive and time consuming. While weakly supervised methods trained using only ordered action lists require less annotation effort, the performance is still worse than fully supervised approaches. In this paper, we propose to use timestamp supervision for the temporal action segmentation task. Timestamps require a comparable annotation effort to weakly supervised approaches, and yet provide a more supervisory signal. To demonstrate the effectiveness of timestamp supervision, we propose an approach to train a segmentation model using only timestamps annotations. Our approach uses the model output and the annotated timestamps to generate frame-wise labels by detecting the action changes. We further introduce a confidence loss that forces the predicted probabilities to monotonically decrease as the distance to the timestamps increases. This ensures that all and not only the most distinctive frames of an action are learned during training. The evaluation on four datasets shows that models trained with timestamps annotations achieve comparable performance to the fully supervised approaches.
The fraction of ionizing photons that escape high-redshift galaxies sensitively determines whether galaxies reionized the early universe. However, this escape fraction cannot be measured from high-redshift galaxies because the opacity of the intergalactic medium is large at high redshifts. Without methods to indirectly measure the escape fraction of high-redshift galaxies, it is unlikely that we will know what reionized the universe. Here, we analyze the far-ultraviolet (UV) H I (Lyman series) and low-ionization metal absorption lines of nine low-redshift, confirmed Lyman continuum emitting galaxies. We use the H I covering fractions, column densities, and dust attenuations measured in a companion paper to predict the escape fraction of ionizing photons. We find good agreement between the predicted and observed Lyman continuum escape fractions (within $1.4\sigma$) using both the H I and ISM absorption lines. The ionizing photons escape through holes in the H I, but we show that dust attenuation reduces the fraction of photons that escape galaxies. This means that the average high-redshift galaxy likely emits more ionizing photons than low-redshift galaxies. Two other indirect methods accurately predict the escape fractions: the Ly$\alpha$ escape fraction and the optical [O III]/[O II] flux ratio. We use these indirect methods to predict the escape fraction of a sample of 21 galaxies with rest-frame UV spectra but without Lyman continuum observations. Many of these galaxies have low escape fractions ($f_{\rm esc} \le 1$\%), but 11 have escape fractions $>1$\%. The methods presented here will measure the escape fractions of high-redshift galaxies, enabling future telescopes to determine whether star-forming galaxies reionized the early universe.
We summarize a novel approach which has been recently proposed for direct detection of low energy neutrino backgrounds such as the cosmological relic neutrinos, exploiting neutrino/antineutrino capture on nuclei that spontaneously undergo beta decay.
The abundance distribution in the ejecta of the peculiar slowly declining Type Ia supernova (SN\,Ia) SN\,1999aa is obtained by modelling a time series of optical spectra. Similar to SN\,1991T, SN\,1999aa was characterised by early-time spectra dominated by \FeIII\ features and a weak \SiII\,6355\,\AA\ line, but it exhibited a high-velocity \CaII\,H\&K line and morphed into a spectroscopically normal SN\,Ia earlier. Three explosion models are investigated, yielding comparable fits. The innermost layers are dominated by $\sim 0.3$\,\Msun\ of neutron-rich stable Fe-group elements, mostly stable iron. Above that central region lies a \Nifs-dominated shell, extending to $v \approx 11,000$ -- $12,000$\,\kms, with mass $\sim 0.65$\,\Msun. These inner layers are therefore similar to those of normal SNe\,Ia. However, the outer layers exhibit composition peculiarities similar to those of SN\,1991T: the intermediate-mass elements shell is very thin, containing only $\sim 0.2$\,\Msun, and is sharply separated from an outer oxygen-dominated shell, which includes $\sim 0.22$\,\Msun. These results imply that burning suddenly stopped in SN\,1999aa. This is a feature SN\,1999aa shares with SN\,1991T, and explain the peculiarities of both SNe, which are quite similar in nature apart from the different luminosities. The spectroscopic path from normal to SN\,1991T-like SNe\,Ia cannot be explained solely by a temperature sequence. It also involves composition layering differences, suggesting variations in the progenitor density structure or in the explosion parameters.
A continuously measured quantum system may be described by restricted path integrals (RPI) or equivalently by non-Hermitian Hamiltonians. The measured system is then considered as an open system, the influence of the environment being taken into account by restricting the path integral or by inclusion of an imaginary part in the Hamiltonian. This way of description of measurements naturally follows from the Feynman form of quantum mechanics without any additional postulates and may be interpreted as an information approach to continuous quantum measurements. This reveals deep features of quantum physics concerning relations between quantum world and its classical appearance.
We examine the problem of the gravitational collapse using higher dimensional Husain spacetime for the null fluid. The equations of state chosen to solve the field equations contain linear, quadratic and arbitrary powers of the radial parameter. The resulting mass evolution is discussed for each case.
In this paper we evaluate the suitability of handwriting patterns as potential biomarkers to model Parkinson disease (PD). Although the study of PD is attracting the interest of many researchers around the world, databases to evaluate handwriting patterns are scarce and knowledge about patterns associated to PD is limited and biased to the existing datasets. This paper introduces a database with a total of 935 handwriting tasks collected from 55 PD patients and 94 healthy controls (45 young and 49 old). Three feature sets are extracted from the signals: neuromotor, kinematic, and nonlinear dynamic. Different classifiers are used to discriminate between PD and healthy subjects: support vector machines, knearest neighbors, and a multilayer perceptron. The proposed features and classifiers enable to detect PD with accuracies between 81% and 97%. Additionally, new insights are presented on the utility of the studied features for monitoring and detecting PD.
We have used laser guide star adaptive optics and a near-infrared dual-channel imaging polarimeter to observe light scattered in the circumstellar environment of Herbig Ae/Be stars on scales of 100-300 AU. We discover a strongly polarized, biconical nebula 10 arcseconds in diameter (6000 AU) around the star LkHa 198, and also observe a polarized jet-like feature associated with the deeply embedded source LkHa 198-IR. The star LkHa 233 presents a narrow, unpolarized dark lane consistent with an optically thick circumstellar disk blocking our direct view of the star. These data show that the lower-mass T Tauri and intermediate mass Herbig Ae/Be stars share a common evolutionary sequence.