pinecone/core-2020-05-10-deduplication huggingface dataset:
Automation of the filament tracking in the framework of the HELIO
  project

We present a new method to automatically track filaments over the solar disk.
The filaments are first detected on Meudon Spectroheliograph H{\alpha} images
of the Sun, applying the technique developed by Fuller, Aboudarham, and Bentley
(Solar phys. 227, 61, 2005). This technique combines cleaning processes, image
segmentation based on region growing, and morphological parameter ex- traction,
including the determination of filament skeletons. The coordinates of the
skeleton pixels, given in a heliocentric system, are then converted to a more
appropriate reference frame that follows the rotation of the Sun surface. In
such a frame, a co-rotating filament is always located around the same
position, and its skeletons (extracted from each image) are thus spatially
close, forming a group of adjacent features. In a third step, the shape of each
skeleton is compared with its neighbours using a curve-matching algorithm. This
step will permit us to define the probability [P ] that two close filaments in
the co-rotating frame are actually the same one observed on two different
images. At the end, the pairs of features, for which the corresponding
probability is greater than a threshold value, are associated using tracking
identification indexes.On a representative sample of filaments, the good
agreement between automated and manual tracking confirms the reliability of the
technique to be applied on large data sets. Especially, this code is already
used in the framework of the Heliophysics Integrated Observatory (HELIO) to
populate a catalogue dedicated to solar and heliospheric features (HFC). An
extension of this method to others filament observations, and possibly the
sunspots, faculae, and coronal holes tracking can be also envisaged
Limb and gravity-darkening coefficients for the TESS satellite at several metallicities, surface gravities, and microturbulent velocities

Aims. We present new gravity and limb-darkening coefficients for a wide range of effective temperatures, gravities, metallicities, and microturbulent velocities. These coefficients can be used in many different fields of stellar physics as synthetic light curves of eclipsing binaries and planetary transits, stellar diameters, line profiles in rotating stars, and others. Methods. The limb-darkening coefficients were computed specifically for the photometric system of the space mission tess and were performed by adopting the least-square method. In addition, the linear and bi-parametric coefficients, by adopting the flux conservation method, are also available. On the other hand, to take into account the effects of tidal and rotational distortions, we computed the passband gravity-darkening coefficients y(λ) using a general differential equation in which we consider the effects of convection and of the partial derivative (ln I(λ)=ln g)Teff. Results. To generate the limb-darkening coefficients we adopt two stellar atmosphere models: atlas (plane-parallel) and phoenix (spherical, quasi-spherical, and r-method). The specific intensity distribution was fitted using five approaches: linear, quadratic, square root, logarithmic, and a more general one with four terms. These grids cover together 19 metallicities ranging from 10-5 up to 10+1 solar abundances, 0 = log g = 6:0 and 1500 K = Teff = 50 000 K. The calculations of the gravity-darkening coefficients were performed for all plane-parallel ATLAS models. © 2017 ESO.The Spanish MEC (AYA2015-71718-R and ESP2015-65712-C5-5-R) is gratefully acknowledged for its support during the development of this work.Peer reviewe
The distribution of mitochondrial DNA haplogroup H in southern Iberia indicates ancient human genetic exchanges along the western edge of the Mediterranean

Background: The structure of haplogroup H reveals significant differences between the western and eastern edges of the Mediterranean, as well as between the northern and southern regions. Human populations along the westernmost Mediterranean coasts, which were settled by individuals from two continents separated by a relatively narrow body of water, show the highest frequencies of mitochondrial haplogroup H. These characteristics permit the analysis of ancient migrations between both shores, which may have occurred via primitive sea crafts and early seafaring. We collected a sample of 750 autochthonous people from the southern Iberian Peninsula (Andalusians from Huelva and Granada provinces). We performed a high-resolution analysis of haplogroup H by control region sequencing and coding SNP screening of the 337 individuals harboring this maternal marker. Our results were compared with those of a wide panel of populations, including individuals from Iberia, the Maghreb, and other regions around the Mediterranean, collected from the literature.\ud
 Results: Both Andalusian subpopulations showed a typical western European profile for the internal composition of clade H, but eastern Andalusians from Granada also revealed interesting traces from the eastern Mediterranean. The basal nodes of the most frequent H sub-haplogroups, H1 and H3, harbored many individuals of Iberian and Maghrebian origins. Derived haplotypes were found in both regions; haplotypes were shared far more frequently between Andalusia and Morocco than between Andalusia and the rest of the Maghreb. These and previous results indicate intense, ancient and sustained contact among populations on both sides of the Mediterranean. \ud
Conclusions: Our genetic data on mtDNA diversity, combined with corresponding archaeological similarities, provide support for arguments favoring prehistoric bonds with a genetic legacy traceable in extant populations. Furthermore, the results presented here indicate that the Strait of Gibraltar and the adjacent Alboran Sea, which have often been assumed to be an insurmountable geographic barrier in prehistory, served as a frequently traveled route between continents
Existence, stability and nonlinear dynamics of vortices and vortex
  clusters in anisotropic Bose-Einstein condensates

We study vortex excitations in one-component Bose-Einstein condensates, with
a special emphasis on the role of anisotropic confinement for the existence,
stability and dynamical properties of vortices and particularly few-vortex
clusters. Symmetry breaking features are pervasive within this system even in
its isotropic installment, where cascades of symmetry breaking bifurcations
give rise to the multi-vortex clusters, but also within the anisotropic realm
which naturally breaks the rotational symmetry of the multi-vortex states. Our
first main tool for analyzing the system consists of a weakly nonlinear
(bifurcation) approach which starts from the linear states of the problem and
examines their continuation and bifurcation into novel symmetry-broken
configurations in the nonlinear case. This is first done in the isotropic limit
and the modifications introduced by the anisotropy are subsequently presented.
The second main tool concerns the highly nonlinear regime where the vortices
can be considered as individual topologically charged "particles" which precess
within the parabolic trap and interact with each other, similarly to fluid
vortices. The conclusions stemming from both the bifurcation and the
interacting particle picture are corroborated by numerical computations which
are also used to bridge the gap between these two opposite-end regimes.Comment: 26 pages, 20 figure
Symmetry-breaking Effects for Polariton Condensates in Double-Well
  Potentials

We study the existence, stability, and dynamics of symmetric and
anti-symmetric states of quasi-one-dimensional polariton condensates in
double-well potentials, in the presence of nonresonant pumping and nonlinear
damping. Some prototypical features of the system, such as the bifurcation of
asymmetric solutions, are similar to the Hamiltonian analog of the double-well
system considered in the realm of atomic condensates. Nevertheless, there are
also some nontrivial differences including, e.g., the unstable nature of both
the parent and the daughter branch emerging in the relevant pitchfork
bifurcation for slightly larger values of atom numbers. Another interesting
feature that does not appear in the atomic condensate case is that the
bifurcation for attractive interactions is slightly sub-critical instead of
supercritical. These conclusions of the bifurcation analysis are corroborated
by direct numerical simulations examining the dynamics of the system in the
unstable regime.Comment: 16 pages, 13 figure
From Coherent Modes to Turbulence and Granulation of Trapped Gases

The process of exciting the gas of trapped bosons from an equilibrium initial
state to strongly nonequilibrium states is described as a procedure of symmetry
restoration caused by external perturbations. Initially, the trapped gas is
cooled down to such low temperatures, when practically all atoms are in
Bose-Einstein condensed state, which implies the broken global gauge symmetry.
Excitations are realized either by imposing external alternating fields,
modulating the trapping potential and shaking the cloud of trapped atoms, or it
can be done by varying atomic interactions by means of Feshbach resonance
techniques. Gradually increasing the amount of energy pumped into the system,
which is realized either by strengthening the modulation amplitude or by
increasing the excitation time, produces a series of nonequilibrium states,
with the growing fraction of atoms for which the gauge symmetry is restored. In
this way, the initial equilibrium system, with the broken gauge symmetry and
all atoms condensed, can be excited to the state, where all atoms are in the
normal state, with completely restored gauge symmetry. In this process, the
system, starting from the regular superfluid state, passes through the states
of vortex superfluid, turbulent superfluid, heterophase granular fluid, to the
state of normal chaotic fluid in turbulent regime. Both theoretical and
experimental studies are presented.Comment: Latex file, 25 pages, 4 figure
Frequency and phase locking of laser cavity solitons

Edited by B. A. Malomed.Self-localized states or dissipative solitons have the freedom of translation in systems with a homogeneous background. When compared to cavity solitons in coherently driven nonlinear optical systems, laser cavity solitons have the additional freedom of the optical phase. We explore the consequences of this additional Goldstone mode and analyze experimentally and numerically frequency and phase locking of laser cavity solitons in a vertical-cavity surface-emitting laser with frequency-selective feedback. Due to growth-related variations of the cavity resonance, the translational symmetry is usually broken in real devices. Pinning to different defects means that separate laser cavity solitons have different frequencies and are mutually incoherent. If two solitons are close to each other, however, their interaction leads to synchronization due to phase and frequency locking with strong similarities to the Adler-scenario of coupled oscillators.P.V.P. acknowledges support from SFB 910; C.M., and Y.N. from EPSRC\ud
DTA; P.C. from MICINN and Feder (FIS2007-60327, FISICOS, TEC2009-14101, DeCoDicA). Y.N. and C.M. were supported by EPSRC DTA/DTG grants.Peer reviewe
Multiple fluxon analogues and dark solitons in linearly coupled
  Bose-Einstein condensates

Two effectively one-dimensional parallel coupled Bose-Einstein condensates in
the presence of external potentials are studied. The system is modelled by
linearly coupled Gross-Pitaevskii equations. In particular, the interactions of
grey-soliton-like solutions representing analogues of superconducting Josephson
fluxons as well as coupled dark solitons are discussed. A theoretical
approximation based on variational formulations to calculate the oscillation
frequency of the grey-soliton-like solution is derived and a qualitatively good
agreement is obtained.Comment: 26 pages, 17 figures. Appeared in "Spontaneous Symmetry Breaking,
  Self-Trapping, and Josephson Oscillations", B.A. Malomed, ed. (Springer,
  Berlin, 2013
Classical dynamics of a two-species Bose-Einstein condensate in the
  presence of nonlinear maser processes

The stability analysis of a generalized Dicke model, in the semi-classical
limit, describing the interaction of a two-species Bose-Einstein condensate
driven by a quantized field in the presence of Kerr and spontaneous parametric
processes is presented. The transitions from Rabi to Josephson dynamics are
identified depending on the relative value of the involved parameters.
Symmetry-breaking dynamics are shown for both types of coherent oscillations
due to the quantized field and nonlinear optical processes.Comment: 12 pages, 5 figures. Accepted for publication as chapter in
  "Spontaneous Symmetry Breaking, Self-Trapping, and Josephson Oscillations in
  Nonlinear Systems
Trapping polarization of light in nonlinear optical fibers: An ideal
  Raman polarizer

The main subject of this contribution is the all-optical control over the
state of polarization (SOP) of light, understood as the control over the SOP of
a signal beam by the SOP of a pump beam. We will show how the possibility of
such control arises naturally from a vectorial study of pump-probe Raman
interactions in optical fibers. Most studies on the Raman effect in optical
fibers assume a scalar model, which is only valid for high-PMD fibers (here,
PMD stands for the polarization-mode dispersion). Modern technology enables
manufacturing of low-PMD fibers, the description of which requires a full
vectorial model. Within this model we gain full control over the SOP of the
signal beam. In particular we show how the signal SOP is pulled towards and
trapped by the pump SOP. The isotropic symmetry of the fiber is broken by the
presence of the polarized pump. This trapping effect is used in experiments for
the design of new nonlinear optical devices named Raman polarizers. Along with
the property of improved signal amplification, these devices transform an
arbitrary input SOP of the signal beam into one and the same SOP towards the
output end. This output SOP is fully controlled by the SOP of the pump beam. We
overview the sate-of-the-art of the subject and introduce the notion of an
"ideal Raman polarizer"
Dust Measurements in the Outer Solar System

Dust measurements in the outer solar system are reviewed. Only the plasma
wave instrument on board Voyagers 1 and 2 recorded impacts in the
Edgeworth-Kuiper belt (EKB). Pioneers 10 and 11 measured a constant dust flux
of 10-micron-sized particles out to 20 AU. Dust detectors on board Ulysses and
Galileo uniquely identified micron-sized interstellar grains passing through
the planetary system. Impacts of interstellar dust grains onto big EKB objects
generate at least about a ton per second of micron-sized secondaries that are
dispersed by Poynting-Robertson effect and Lorentz force. We conclude that
impacts of interstellar particles are also responsible for the loss of dust
grains at the inner edge of the EKB. While new dust measurements in the EKB are
in an early planning stage, several missions (Cassini and STARDUST) are en
route to analyze interstellar dust in much more detail.Comment: 10 pages, 5 figures, Proceedings of the ESO workshop on ``Minor
  bodies in the outer solar system'
Modular termination proofs for prolog with tabling

Tabling avoids many of the shortcomings of SLD(NF) execution and provides a more flexible and efficient execution mechanism for logic programs. In particular, tabled execution of logic programs terminates more often than execution based on SLD-resolution. One of the few works studying termination under a tabled execution mechanism is that of Decorte et al. They introduce and characterise two notions of universal termination of logic programs w.r.t. sets of queries executed under SLG-resolution, using the left-to-right selection rule; namely the notion of quasi-termination and the (stronger) notion of LG-termination. This paper extends the results of Decorte ct al in two ways: (1) we consider a mix of tabled and Prolog execution, and (2) besides a characterisation of the two notions of universal termination under such a mixed execution, we also give modular termination conditions. From both practical and efficiency considerations, it is important to allow tabled and non-tabled predicates to be freely intermixed. This motivates the first extension. Concerning the second extension, it was already noted in the literature in the context of termination under SLD-resolution (by e.g. Apt and Pedreschi), that it is important for programming in the large to have modular termination proofs, i.e. proofs that are capable of combining termination proofs of separate programs to obtain termination proofs of combined programs.status: publishe
Termination analysis of tabled logic programs using mode and type information

Tabled logic programming is receiving increasing attention in the Logic Programming community. It avoids many of the shortcomings of SLD(NF) execution and provides a more flexible and efficient execution mechanism for logic programs. In particular, tabled execution of logic programs terminates more often than execution based on SLD-resolution. One of the few approaches studying termination of tabled logic programs was developed by Decorte et al. They present necessary and sufficient conditions for two notions of universal termination under SLG-resolution, the resolution principle of tabling: quasi-termination and (the stronger notion of) LG-termination. Starting from these necessary and sufficient conditions, we introduce sufficient conditions which are stated fully at the clause level and axe easy to automatize. To this end, we use mode and type information: we consider simply moded, well-typed programs and queries. We point out how our termination conditions can be automatized, by extending the recently developed constraint-based automatic termination analysis for SLD-resolution by Decorte and De Schreye.status: publishe
Population III by Popular Demand - Progress and Previews

I discuss the ongoing search for stars of the Milky Way which have been
referred to as members of Population III. Following a discussion of possible
definitions for these stars, I consider the reasons why astronomers have
undertaken this search, and list some of the numerous astrophysical uses of the
extremely metal-poor stars found along the way. I then review survey techniques
which have been used in the past, and provide an update on plans for future
investigations. Finally, the question of when one might consider the search for
Population III Finished is addressed.Comment: 12 pages, 0 figures, to appear in proceedings of THE FIRST STARS
  meeting, held in Garching, Germany, August 199
Did the Universe start at Zero Metallicity?

Standard Big Bang nucleosynthesis predicts an essentially zero primordial
metallicity. I speculate on possible metal (i.e. nucleon number A\geq 12)
production in scenarios of inhomogeneous Big Bang nucleosynthesis. It is
conceivable, though not necessarily probable, that some primordial metallicity
is synthesized if a small fraction of all cosmic baryons reside in very
high-density regions. Such conditions could possibly result from the
evaporation of some baryon-number carrying soliton prior to the epoch of Big
Bang nucleosynthesis.Comment: 4 pages, to appear in proceedings of The First Stars meeting, held in
  Garching, Germany, August 199
Chemical Yields from the First Stars

We examine the dependence of stellar yields on the metallicity Z of the
stellar population. This effect may be important for the very first chemical
enrichment from Population III stars, at very low Z. In the range of massive
stars, mass loss rates varying with Z have remarkable effects.
  We also estimate chemical yields from Very Massive Objects (from 120 to 1000
Mo), which might have formed more easily in the very low-Z environment of the
first stellar generations.Comment: 5 pages, 7 figures, to appear in The First Stars, Proceedings of the
  second MPA/ESO workshop, Eds.: Weiss, Abel, Hill, Springer, Heidelberg, 200
Evolution and Nucleosynthesis of Metal-Free Massive Stars

We calculate presupernova evolutions and supernova explosions of massive
stars (M=13-25 Mo) for various metallicities. We find the following
characteristic abundance patterns of nucleosynthesis in the metal-free (Pop
III) stars. (1) The alpha-nuclei (from C to Zn) are more efficiently produced
than other isotopes, and the abundance pattern of alpha-nuclei can be similar
to the solar abundance. In particular, near solar ratios of alpha elements/Fe
might be a signature of Pop III which could produce a large amount of Fe. (2)
The abundance ratios of odd Z to even Z elements such as Na/Mg and Al/Mg become
smaller for lower metallicity. However, these ratios almost saturate below Z <~
10^{-5}, and [Na, Al/Mg] ~ - 1 for Pop III and low metal Pop II
nucleosynthesis. This result is consistent with abundance pattern of metal poor
stars, in which these ratios also saturate around -1. We suggest that these
stars with the lowest [Na/Mg] or [Al/Mg] may contain the abundance pattern of
Pop III nucleosynthesis. (3) Metal poor stars show interesting trends in the
ratios of [Cr, Mn, Co/Fe]. We discuss that these trends are not explained by
the differences in metallicity, but by the relative thickness between the
complete and the incomplete Si burning layers. Large [Co/Fe] and small [Cr,
Mn/Fe] values found in the observations are explained if mass cut is deep or if
matter is ejected from complete Si burning layer in a form of a jet or bullets.
(4) We also find that primary ^{14}N production occurs in the massive Pop III
stars, because these stars have radiative H-rich envelopes so that the
convective layer in the He-shell burning region can reach the H-rich region.Comment: 19 pages. To appear in the proceedings of the MPA/ESO conference
  ``The First Stars'' (August 4-7, 1999, Garching) ed. A. Weiss etal.
  (Springer
Death of Stellar Baryonic Dark Matter

The nature of the dark matter in the haloes of galaxies is one of the
outstanding questions in astrophysics. All stellar candidates, until recently
thought to be likely baryonic contributions to the Halo of our Galaxy, are
shown to be ruled out. Faint stars and brown dwarfs are found to constitute
only a few percent of the mass of the Galaxy. Stellar remnants, including white
dwarfs and neutron stars, are shown to be very constrained as well. High energy
gamma-rays observed in HEGRA data place the strongest constraints, $\Omega_{WD}
< 3 \times 10^{-3} h^{-1}$, where $h$ is the Hubble constant in units of 100 km
s$^{-1}$ Mpc$^{-1}$. Hence one is left with several unanswered questions: 1)
What are MACHOs seen in microlensing surveys? 2) What is the dark matter in our
Galaxy? Indeed a nonbaryonic component in the Halo seems to be required.Comment: 6 pages ps fil