ShantanuT01/DACTYL-Pretraining huggingface dataset:
We report on the X-ray time resolved spectral analysis of XMM-Newton observations of NGC 3783. The main goal is to detect transient features in the Fe K line complex, in order to study the dynamics of the innermost accretion flow. We reanalize archival observations of NGC 3783, a bright local AGN, for which a transient Fe line was reported, complementing this data set with new available observations. This results in a long set of observations which can allow us to better assess the significance of transient features and possibly test their recurrence time. Moreover, since the new data catch the source in an obscured state, this analysis allows also to test whether the appearance/disappearance of transient features is linked to the presence of obscuring gas. We detect discrete features at the >=90% significance level both in emission and in absorption at different times of the observations, split into 5ks time-resolved spectra. The overall significance of individual features is higher in the obscured dataset. The energy distribution of the detections changes between the two states of the source, and the features appear to cluster at different energies. Counting the occurrences of emission/absorption lines at the same energies, we identify several groups of $\geq3\sigma$ detections: emission features in the 4-6 keV band are present in all observations and are most likely due to effects of the absorber present in the source; an emission line blend of neutral Fe K$\beta$/ionized Fe Ka is present in the unobscured dataset; absorption lines produced by gas at different ouflowing velocities and ionization states show an increase in energy between the two epochs, shifting from ~6 keV to ~6.7-6.9 keV. The representation of the features in a time-energy plane via residual maps highlighted a possible modulation of the Fe Ka line intensity, linked to the clumpiness of the absorbing medium.
In any simple polygonal art gallery with n walls, we show that it is possible to place floor(n/2)-1 guards whose range of vision is 180 degrees in such a way that every interior point of the gallery can be seen by one of them, and such that the mutual visibility graph formed by the guards is connected. This upper bound is tight, in that there exist galleries which require this number of guards, and equals the known result for guards with full 360 degree range of vision. We also show that for orthogonal art galleries, this result may be improved to floor(n/2)-2 guards with 180 degree range of vision.
We consider large time behavior of solutions to the nonlinear Schr\"odinger equation with a homogeneous nonlinearity of the critical order which is not necessarily a polynomial. We treat the case in which the nonlinearity contains non-oscillating factor $|u|^{1+2/d}$. The case is excluded in our previous studies. It turns out that there are no solutions that behave like a free solution with or without logarithmic phase corrections. We also prove nonexistence of an asymptotic free solution in the case that the gauge invariant nonlinearity is dominant, and give a finite time blow-up result.
We consider the following time-independent nonlinear $L^2$-critical Schr\"{o}dinger equation \[ -\Delta u(x)+V(x)u(x)-a|x|^{-b}|u|^{1+\frac{4-2b}{N}}=\mu u(x)\,\ \hbox{in}\,\ \mathbb{R}^N, \] where $\mu\in\mathbb{R}$, $a>0$, $N\geq 1$, $0<b<\min\{2,N\}$, and $V(x)$ is an external potential. It is shown that ground states of the above equation can be equivalently described by minimizers of the corresponding minimization problem. In this paper, we prove that there is a threshold $a^*>0$ such that minimizer exists for $0<a<a^*$ and minimizer does not exist for any $a>a^*$. However if $a=a^*$, it is proved that whether minimizer exists depends sensitively on the value of $V(0)$. Moreover, when there is no minimizer at threshold $a^*$, we give a detailed concentration behavior of minimizers as $a\nearrow a^*$, based on which we finally prove that there is a unique minimizer as $a\nearrow a^*$.
We continue our study of genus 2 curves $C$ that admit a cover $ C \to E$ to a genus 1 curve $E$ of prime degree $n$. These curves $C$ form an irreducible 2-dimensional subvariety $\L_n$ of the moduli space $\M_2$ of genus 2 curves. Here we study the case $n=5$. This extends earlier work for degree 2 and 3, aimed at illuminating the theory for general $n$.   We compute a normal form for the curves in the locus $\L_5$ and its three distinguished subloci. Further, we compute the equation of the elliptic subcover in all cases, give a birational parametrization of the subloci of $\L_5$ as subvarieties of $\M_2$ and classify all curves in these loci which have extra automorphisms.
We compute the expected dimension of the moduli space of torsion-free rank 2 sheaves at a point corresponding to a stable reflexive sheaf and give conditions for the existence of a perfect tangent-obstruction complex on a class of smooth projective threefolds; this class includes Fano and Calabi-Yau threefolds. We also explore both local and global relationships between moduli spaces of reflexive rank 2 sheaves and the Hilbert scheme of curves.
We discuss a framework for communicating supersymmetry breaking to the visible sector where the radius modulus, which determines the size of extra dimensions, has an auxiliary vacuum expectation value. The modulus couplings generate mass splitting in Kaluza-Klein supermultiplets and they act as messengers of supersymmetry breaking. The soft masses are expressed in terms of renormalization-group functions and the sparticle spectrum is determined by what kind of field propagates in the bulk. This framework also provides new possibilities for solving the supersymmetric flavor problem.
The over-dense environments of protoclusters of galaxies in the early Universe (z>2) are expected to accelerate the evolution of galaxies, with an increased rate of stellar mass assembly and black hole accretion compared to co-eval galaxies in the average density `field'. These galaxies are destined to form the passive population of massive systems that dominate the cores of rich clusters today. While signatures of accelerated growth of galaxies in the SSA22 protocluster (z=3.1) have been observed, the mechanism driving this remains unclear. Here we show an enhanced rate of galaxy-galaxy mergers could be responsible. We morphologically classify Lyman-break Galaxies (LBGs) in the SSA22 protocluster and compare these to those of galaxies in the field at z=3.1 as either active mergers or non-merging using Hubble Space Telescope ACS/F814W imaging, probing the rest-frame ultraviolet stellar light. We measure a merger fraction of 48+/-10 per cent for LBGs in the protocluster compared to 30+/-6 per cent for the field. Although the excess is marginal, an enhanced rate of mergers in SSA22 hints that galaxy-galaxy mergers are one of the key channels driving accelerated star formation and AGN growth in protocluster environments.
From the first stages of star and galaxy formation, non-gravitational processes such as ram pressure stripping, SNs, galactic winds, AGNs, galaxy-galaxy mergers, etc... lead to the enrichment of the IGM in stars, metals as well as dust, via the ejection of galactic material into the IGM. We know now that these processes shape, side by side with gravitation, the formation and the evolution of structures. We present here hydrodynamic simulations of structure formation implementing the effect of the cooling by dust on large scale structure formation. We focus on the scale of galaxy clusters and study the statistical properties of clusters. Here we present our results on the $T_X-M$ and the $L_X-M$ scaling relations which exhibit changes on both the slope and normalization when adding cooling by dust to the standard radiative cooling model. For example, the normalization of the $T_X-M$ relation changes only by a maximum of 2% at $M=10^{14}$ M$_\odot$ whereas the normalization of the $L_X-T_X$ changes by as much as 10% at $T_X=1$ keV for models that including dust cooling. Our study shows that the dust is an added non-gravitational process that contributes shaping the thermodynamical state of the hot ICM gas.
We present a fully self-consistent computational framework composed by Hartree-Fock plus ran- dom phase approximation where the spin-orbit and Coulomb terms of the interaction are included in both steps of the calculations. We study the effects of these terms of the interaction on the random phase approximation calculations, where they are usually neglected. We carry out our investigation of excited states in spherical nuclei of oxygen, calcium, nickel, zirconium, tin and lead isotope chains. We use finite-range effective nucleon-nucleon interactions of Gogny type. The size of the effects we find is, usually, of few hundreds of keV. There are not simple approximations which can be used to simulate these effects since they strongly depend on all the variables related to the excited states, angular momentum, parity, excitation energy, isoscalar and isovector characters. Even the Slater approximation developed to account for the Coulomb exchange terms in Hartree-Fock is not valid in random phase approximation calculations.
The direct interaction of the 4-rotational (Lorentzian) gauge field with the angular orbital momentum of an external field is considered. This interaction appears in a new Poincar\'{e} gauge theory of gravitation, in which tetrads are not true gauge fields, but represent some functions of the translational and 4-rotational gauge fields. The given interaction leads to a new effect: the existence of an electronic orbits precession under the action of an intensive external gravitational field (gravidiamagnetic effect), and also substantiates the existence of the direct interaction of the proper angular momentum of a gyroscope with the torsion field, which theoretically can be generated by the rotational angular momentum of the planet the Earth. The latter interaction can be detected by the experiment Gravity Probe B on the satellite orbit.
Using the Ratios Conjecture, we write down precise formulas with lower order terms for the one and the two level densities of zeros of quadratic Dirichlet $L$--functions over function fields. We denote the various terms arising as Type-$0$, Type-I and Type-II contributions. When the support of the Fourier transform of the test function is sufficiently restricted, we rigorously compute the Type-$0$ and Type-I terms and confirm that they match the conjectured answer. When the restrictions on the support are relaxed, our results suggest that Type-II contributions become important in the two level density.
We make a global vacuum neutrino oscillation analysis of solar neutrino data, including the seasonal and energy dependence of the recent Super-Kamiokande 708-day results. The best fit parameters for \nu_e oscillations to an active neutrino are \delta m^2 = 4.42\times10^{-10} eV^2, \sin^2 2\theta = 0.93. The allowed mixing angle region is consistent with bi-maximal mixing of three neutrinos. Oscillations to a sterile neutrino are disfavored. Allowing an enhanced hep neutrino flux does not significantly alter the oscillation parameters.
Arbitrary amplitude nonlinear ion waves is investigated in an extremely degenerate electron-positron-ion plasma with relativistic electrons/positrons and dynamic cold ions using Sagdeev pseudo-potential method in framework of quantum hydrodynamics model. The matching criteria of existence for ion solitary as well as periodic nonlinear excitations is studied numerically in terms of the relativistic degeneracy parameter, relative positron concentration and the relativistic normalized propagation-speed range of these waves are obtained. It is remarked that the electron relativistic degeneracy and relative positron concentration in such plasmas have significant effects on nonlinear wave propagations in relativistically degenerate Fermi-Dirac plasma. Our results are in good agreement with the previously reported ones obtained using semiclassical Thomas-Fermi approximation in dense plasmas with non-relativistic and ultra-relativistic electrons and positrons. Current findings can be appropriate for the study of astrophysical superdense compact objects such as white dwarfs.
It has been shown in an earlier work [arXiv:1303.1535] that there exists a pair of canonically conjugate variables $(f^{ab},N^a_{bc})$ in general relativity which also act as thermodynamically conjugate variables on any horizon. In particular their variations $(f^{bc}\delta N^a_{bc}, N^a_{bc}\delta f^{bc})$, which occur in the surface term of the Einstein-Hilbert action, when integrated over a null surface, have direct correspondence with $(S\delta T,T\delta S)$ where $(T,S)$ are the temperature and entropy. We generalize these results to Lanczos-Lovelock models in this paper. We identify two such variables in Lanczos-Lovelock models such that (a) our results reduce to that of general relativity in the appropriate limit and (b) the variation of surface term in the action, when evaluated on a null surface, has direct thermodynamic interpretation as in the case of general relativity. The variations again correspond to $S\delta T$ and $T\delta S$ where $S$ is now the appropriate Wald entropy for the Lanczos-Lovelock model. The implications are discussed.
A relationship between dust-reprocessed light from recent star formation and the amount of star-forming gas in a galaxy produces a correlation between WISE 12 $\mu$m emission and CO line emission. Here we explore this correlation on kiloparsec scales with CO(1-0) maps from EDGE-CALIFA matched in resolution to WISE 12 $\mu$m images. We find strong CO-12 $\mu$m correlations within each galaxy and we show that the scatter in the global CO-12 $\mu$m correlation is largely driven by differences from galaxy to galaxy. The correlation is stronger than that between star formation rate and H$_2$ surface densities ($\Sigma(\mathrm{H_2})$). We explore multi-variable regression to predict $\Sigma(\mathrm{H_2})$ in star-forming pixels using the WISE 12 $\mu$m data combined with global and resolved galaxy properties, and provide the fit parameters for the best estimators. We find that $\Sigma(\mathrm{H_2})$ estimators that include $\Sigma(\mathrm{12\>\mu m})$ are able to predict $\Sigma(\mathrm{H_2})$ more accurately than estimators that include resolved optical properties instead of $\Sigma(\mathrm{12\>\mu m})$. These results suggest that 12 $\mu$m emission and H$_2$ as traced by CO emission are physically connected at kiloparsec scales. This may be due to a connection between polycyclic aromatic hydrocarbon (PAH) emission and the presence of H$_2$. The best single-property estimator is $\log \frac{\Sigma(\mathrm{H_2})}{\mathrm{M_\odot\>pc^{-2}}} = (0.48 \pm 0.01) + (0.71 \pm 0.01)\log \frac{\Sigma(\mathrm{12\>\mu m})}{\mathrm{L_\odot\>pc^{-2}}}$. This correlation can be used to efficiently estimate $\Sigma(\mathrm{H_2})$ down to at least $1 \> M_\odot \> \mathrm{pc^{-2}}$ in star-forming regions within nearby galaxies.
We study an atomic Bose-Fermi mixture in an optical lattice which is confined using an optical trap. We obtain the Mott ground states of such a system in the limit of deep optical lattice and discuss the effect of quantum fluctuations on these states. We also study the superfluid-insulator transitions of bosons and metal-insulator transition of fermions in such a mixture within a slave-rotor mean-field approximation, and obtain the corresponding phase diagram. We discuss experimental implications of our results.
Let $G=(G_j)_{j\ge 0}$ be a strictly increasing linear recurrent sequence of integers with $G_0=1$ having characteristic polynomial $X^{d}-a_1X^{d-1}-\cdots-a_{d-1}X-a_d$. It is well known that each positive integer $\nu$ can be uniquely represented by the so-called greedy expansion $\nu=\varepsilon_0(\nu)G_0+\cdots+\varepsilon_\ell(\nu)G_\ell$ for $\ell \in \mathbb{N}$ satisfying $G_\ell \le \nu < G_{\ell+1}$. Here the digits are defined recursively in a way that $0\le \nu - \varepsilon_{\ell}(\nu) G_\ell - \cdots - \varepsilon_j(\nu) G_j < G_j$ holds for $0 \le j \le \ell$. In the present paper we study the sum-of-digits function $s_G(\nu)=\varepsilon_0(\nu)+\cdots+\varepsilon_\ell(\nu)$ under certain natural assumptions on the sequence $G$. In particular, we determine its level of distribution $x^{\vartheta}$. To be more precise, we show that for $r,s\in\mathbb{N}$ with $\gcd(a_1+\cdots+a_d-1,s)=1$ we have for each $x\ge 1$ and all $A,\varepsilon\in\mathbb{R}_{>0}$ that \[ \sum_{q<x^{\vartheta-\varepsilon}}\max_{z<x}\max_{1\leq h\leq q}   \lvert\sum_{\substack{k<z,s_G(k)\equiv r\bmod s\\ k\equiv h\bmod q}}1   -\frac1q\sum_{k<z,s_G(k)\equiv r\bmod s}1\rvert   \ll x(\log 2x)^{-A}. \] Here $\vartheta=\vartheta(G) \ge \frac12$ can be computed explicitly and we have $\vartheta(G) \to 1$ for $a_1\to\infty$. As an application we show that $\#\{ k\le x \,:\, s_G(k) \equiv r \pmod{s}, \; k \hbox{ has at most two prime factors} \} \gg x/\log x $ provided that the coefficient $a_1$ is not too small. Moreover, using Bombieri's sieve an "almost prime number theorem" for $s_G$ follows from our result.   Our work extends earlier results on the classical $q$-ary sum-of-digits function obtained by Fouvry and Mauduit.
We prove the existence of one or more solutions to a singularly perturbed elliptic problema with two potential functions.
We prove, under some assumptions, the existence of correctors for the stochastic homoge-nization of of " viscous " possibly degenerate Hamilton-Jacobi equations in stationary ergodic media. The general claim is that, assuming knowledge of homogenization in probability, correctors exist for all extreme points of the convex hull of the sublevel sets of the effective Hamiltonian. Even when homogenization is not a priori known, the arguments imply existence of correctors and, hence, homogenization in some new settings. These include positively homogeneous Hamiltonians and, hence, geometric-type equations including motion by mean curvature, in radially symmetric environments and for all directions. Correctors also exist and, hence, homogenization holds for many directions for non convex Hamiltoni-ans and general stationary ergodic media.
The time delays between the components of a lensed quasar are basic tools to analyze the expansion of the Universe and the structure of the main lens galaxy halo. In this paper, we focus on the variability and time delay of the double system SBS 0909+532A,B as well as the time behaviour of the field stars. We use VR optical observations of SBS 0909+532A,B and the field stars in 2003. The frames were taken at Calar Alto, Maidanak and Wise observatories, and the VR light curves of the field stars and quasar components are derived from aperture and point-spread function fitting methods. We measure the R-band time delay of the system from the chi-square and dispersion techniques and 1000 synthetic light curves based on the observed records. One nearby field star (SBS 0909+532c) is found to be variable, and the other two nearby field stars are non-variable sources. With respect to the quasar components, the R-band records seem more reliable and are more densely populated than the V-band ones. The observed R-band fluctuations permit a pre-conditioned measurement of the time delay. From the chi-square minimization, if we assume that the quasar emission is observed first in B and afterwards in A (in agreement with basic observations of the system and the corresponding predictions), we obtain a delay of - 45 (+ 1)/(- 11) days (95% confidence interval). The dispersion technique leads to a similar delay range. A by-product of the analysis is the determination of a totally corrected flux ratio in the R band (corrected by the time delay and the contamination due to the galaxy light). Our 95% measurement of this ratio (0.575 +/- 0.014 mag) is in excellent agreement with previous results from contaminated fluxes at the same time of observation.
Deep convolutional networks have attracted great attention in image restoration and enhancement. Generally, restoration quality has been improved by building more and more convolutional block. However, these methods mostly learn a specific model to handle all images and ignore difficulty diversity. In other words, an area in the image with high frequency tend to lose more information during compressing while an area with low frequency tends to lose less. In this article, we adrress the efficiency issue in image SR by incorporating a patch-wise rolling network(PRN) to content-adaptively recover images according to difficulty levels. In contrast to existing studies that ignore difficulty diversity, we adopt different stage of a neural network to perform image restoration. In addition, we propose a rolling strategy that utilizes the parameters of each stage more flexible. Extensive experiments demonstrate that our model not only shows a significant acceleration but also maintain state-of-the-art performance.
We use the latest version of the metal line absorption catalogue of Zhu & M\'enard (2013) to study the clustering of MgII absorbers around massive galaxies (~10^11.5 M_sun), quasars and radio-loud AGN with redshifts between 0.4 and 0.75. Clustering is evaluated in two dimensions, by binning absorbers both in projected radius and in velocity separation. Excess MgII is detected around massive galaxies out to R_p=20 Mpc. At projected radii less than 800 kpc, the excess extends out to velocity separations of 10,000 km/s. The extent of the high velocity tail within this radius is independent of the mean stellar age of the galaxy and whether or not it harbours an active galactic nucleus. We interpret our results using the publicly available Illustris and Millennium simulations. Models where the MgII absorbers trace the dark matter particle or subhalo distributions do not fit the data. They overpredict the clustering on small scales and do not reproduce the excess high velocity separation MgII absorbers seen within the virial radius of the halo. The Illustris simulations which include thermal, but not mechanical feedback from AGN, also do not provide an adequate fit to the properties of the cool halo gas within the virial radius. We propose that the large velocity separation MgII absorbers trace gas that has been pushed out of the dark matter halos, possibly by multiple episodes of AGN-driven mechanical feedback acting over long timescales.
Working over a perfect field, I classify normal del Pezzo surfaces with base number one that contain a nonrational singularity. They form a huge infinite hierarchy; contractions of ruled surfaces lie on top of it. Descending the hierarchy hinges on a generalized version of elementary transformations. As an application, I determine the structure of 2-dimensional anticanonical models for arbitrary normal surfaces.
We have obtained spectroscopy with the Far Ultraviolet Spectroscopic Explorer (FUSE) of the supersoft X-ray binary RX J0513.9-6951 over a complete binary orbital cycle. The spectra show a hot continuum with extremely broad O VI emission and weak Lyman absorptions. He II emission is weak and narrow, while N III and C III emissions are undetected, although lines from these ions are prominent at optical wavelengths. The broad O VI emission and Lyman absorption show radial velocity curves that are approximately antiphased and have semiamplitudes of ~117 +- 40 and 54 +- 10 km/s, respectively. Narrow emissions from He II and O VI show small velocity variations with phasing different from the broad O VI, but consistent with the optical line peaks. We also measure considerable changes in the FUV continuum and O VI emission line flux. We discuss the possible causes of the measured variations and a tentative binary interpretation.