pinecone/core-2020-05-10-deduplication huggingface dataset:
Influence of air parcel trajectories on CO2 and CH4 concentrations in the northern plateau of the Iberian Peninsula

This study presents a simpler procedure for grouping air parcel back trajectories than others previously applied. Two-day air parcel back trajectories reaching an unpolluted site in the centre of the northern plateau of the Iberian Peninsula were calculated over a three-year period using the METEX model. A procedure based on the kernel density calculation was applied to the direction of each trajectory centroid to determine groups of trajectories.
This method is much faster than the cluster procedure when it comes to retaining the directional details of groups. Seasonal analysis of six groups of trajectories revealed that the Atlantic origin prevailed against displacement from northern Europe. Moreover, Mediterranean and particularly African trajectories were infrequent, probably due to the rough peninsular orography in these directions. The location of air trajectories reaching the study site was described using a surface classification below the air parcels with improved spatial
resolution compared to previous analyses. Local contribution was very marked, particularly in summer. Mean trajectories were calculated for each group together with meteorological features and CO2 and CH4 concentrations. Groups may be identified by their mean temperature, wind speed, elevation and distance values. However, only two groups should be considered when analysing the two trace gases, one for trajectories from the Atlantic
Ocean and the second for trajectories from the continent. Contrasts of about 4 ppm for CO2 in summer and 0.023 ppm for CH4 in winter were observed, revealing that air trajectories from the Atlantic Ocean were cleaner than those arriving from the continent. These differences were attributed to higher air stagnation over land.the Ministry of Economy and Competitiveness and ERDF funds (projects CGL2009-11979 and CGL2014-53948-P
Age-structured Trait Substitution Sequence Process and Canonical
  Equation

We are interested in a stochastic model of trait and age-structured
population undergoing mutation and selection. We start with a continuous time,
discrete individual-centered population process. Taking the large population
and rare mutations limits under a well-chosen time-scale separation condition,
we obtain a jump process that generalizes the Trait Substitution Sequence
process describing Adaptive Dynamics for populations without age structure.
Under the additional assumption of small mutations, we derive an age-dependent
ordinary differential equation that extends the Canonical Equation. These
evolutionary approximations have never been introduced to our knowledge. They
are based on ecological phenomena represented by PDEs that generalize the
Gurtin-McCamy equation in Demography. Another particularity is that they
involve a fitness function, describing the probability of invasion of the
resident population by the mutant one, that can not always be computed
explicitly. Examples illustrate how adding an age-structure enrich the
modelling of structured population by including life history features such as
senescence. In the cases considered, we establish the evolutionary
approximations and study their long time behavior and the nature of their
evolutionary singularities when computation is tractable. Numerical procedures
and simulations are carried
Ionization in atmospheres of brown dwarfs and extrasolar planets. IV. The effect of cosmic rays

Cosmic rays provide an important source for free electrons in Earth's atmosphere and also in dense interstellar regions where they produce a prevailing background ionization. We utilize a Monte Carlo cosmic ray transport model for particle energies of 10(6) eV <E <10(9) eV, and an analytic cosmic ray transport model for particle energies of 10(9) eV <E <10(12) eV in order to investigate the cosmic ray enhancement of free electrons in substellar atmospheres of free-floating objects. The cosmic ray calculations are applied to Drift-Phoenix model atmospheres of an example brown dwarf with effective temperature T-eff = 1500 K, and two example giant gas planets (T-eff = 1000 K, 1500 K). For the model brown dwarf atmosphere, the electron fraction is enhanced significantly by cosmic rays when the pressure p(gas) <10(-2) bar. Our example giant gas planet atmosphere suggests that the cosmic ray enhancement extends to 10(-4)-10(-2) bar, depending on the effective temperature. For the model atmosphere of the example giant gas planet considered here (T-eff = 1000 K), cosmic rays bring the degree of ionization to f(e) greater than or similar to 10(-8) when p(gas) <10(-8) bar, suggesting that this part of the atmosphere may behave as a weakly ionized plasma. Although cosmic rays enhance the degree of ionization by over three orders of magnitude in the upper atmosphere, the effect is not likely to be significant enough for sustained coupling of the magnetic field to the gas.Publisher PDFPeer reviewe
Asymptotic Euler-Maclaurin formula over lattice polytopes

An asymptotic expansion formula of Riemann sums over lattice polytopes is
given. The formula is an asymptotic form of the local Euler-Maclaurin formula
due to Berline-Vergne. The proof given here for Delzant lattice polytopes is
independent of the local Euler-Maclaurin formula. But we use it for general
lattice polytopes. As corollaries, an explicit formula for each term in the
expansion over Delzant polytopes in two dimension and an explicit formula for
the third term of the expansion for Delzant polytopes in arbitrary dimension
are given. Moreover, some uniqueness results are given.Comment: 35 pages. Results in the previous version are generalized to lattice
  polytopes. Some further results are added. The title is changed. The
  organization is changed to clarify the discussion
Correlated X-ray and Very High Energy emission in the gamma-ray binary
  LS I +61 303

The discovery of very high energy (VHE) gamma-ray emitting X-ray binaries has
triggered an intense effort to better understand the particle acceleration,
absorption, and emission mechanisms in compact binary systems, which provide
variable conditions along eccentric orbits. Despite this, the nature of some of
these systems, and of the accelerated particles producing the VHE emission, is
unclear. To answer some of these open questions, we conducted a multiwavelength
campaign of the VHE gamma-ray emitting X-ray binary LS I +61 303 including the
MAGIC telescope, XMM-Newton, and Swift during 60% of an orbit in 2007
September. We detect a simultaneous outburst at X-ray and VHE bands, with the
peak at phase 0.62 and a similar shape at both wavelengths. A linear fit to the
simultaneous X-ray/VHE pairs obtained during the outburst yields a correlation
coefficient of r=0.97, while a linear fit to all simultaneous pairs provides
r=0.81. Since a variable absorption of the VHE emission towards the observer is
not expected for the data reported here, the correlation found indicates a
simultaneity in the emission processes. Assuming that they are dominated by a
single particle population, either hadronic or leptonic, the X-ray/VHE flux
ratio favors leptonic models. This fact, together with the detected photon
indices, suggests that in LS I +61 303 the X-rays are the result of synchrotron
radiation of the same electrons that produce VHE emission as a result of
inverse Compton scattering of stellar photons.Comment: To appear in The Astrophysical Journal Letters. 6 pages, 2 figure
Star formation in the Taurus filament L1495: From Dense Cores to Stars

We present a study of dense structures in the L1495 filament in the Taurus
Molecular Cloud and examine its star-forming properties. In particular we
construct a dust extinction map of the filament using deep near-infrared
observations, exposing its small-scale structure in unprecedented detail. The
filament shows highly fragmented substructures and a high mass-per-length value
of M_line=17 Msun/pc, reflecting star-forming potential in all parts of it.
However, a part of the filament, namely B211, is remarkably devoid of young
stellar objects. We argue that in this region the initial filament collapse and
fragmentation is still taking place and star formation is yet to occur. In the
star-forming part of the filament, we identify 39 cores with masses from
0.4...10 Msun and preferred separations in agreement with the local Jeans
length. Most of these cores exceed the Bonnor-Ebert critical mass, and are
therefore likely to collapse and form stars. The Dense Core Mass Function
follows a power law with exponent Gamma=1.2, a form commonly observed in
star-forming regions.Comment: 11 pages, 13 figures, accepted for publication in Ap
Multiplicity of Galactic Cepheids from long-baseline interferometry I.
  CHARA/MIRC detection of the companion of V1334 Cygni

We aim at determining the masses of Cepheids in binary systems, as well as
their geometric distances and the flux contribution of the companions. The
combination of interferometry with spectroscopy will offer a unique and
independent estimate of the Cepheid masses. Using long-baseline interferometry
at visible and infrared wavelengths, it is possible to spatially resolve binary
systems containing a Cepheid down to milliarcsecond separations. Based on the
resulting visual orbit and radial velocities, we can then derive the
fundamental parameters of these systems, particularly the masses of the
components and the geometric distance. We therefore performed interferometric
observations of the first-overtone mode Cepheid V1334 Cyg with the CHARA/MIRC
combiner. We report the first detection of a Cepheid companion using
long-baseline interferometry. We detect the signature of a companion orbiting
V1334 Cyg at two epochs. We measure a flux ratio between the companion and the
Cepheid f = 3.10+/-0.08%, giving an apparent magnitude mH = 8.47+/-0.15mag. The
combination of interferometric and spectroscopic data have enabled the unique
determination of the orbital elements: P = 1938.6+/-1.2 days, Tp = 2 443
616.1+/-7.3, a = 8.54+/-0.51mas, i = 124.7+/-1.8{\deg}, e = 0.190+/-0.013,
{\omega} = 228.7+/-1.6{\deg}, and {\Omega} = 206.3+/-9.4{\deg}. We derive a
minimal distance d ~ 691 pc, a minimum mass for both stars of 3.6 Msol, with a
spectral type earlier than B5.5V for the companion star. Our measured flux
ratio suggests that radial velocity detection of the companion using
spectroscopy is within reach, and would provide an orbital parallax and
model-free masses.Comment: Published in A&
Polyakov-Quark-Meson-Diquark Model for two-color QCD

We present an update on the phase diagram of two-color QCD from a chiral
effective model approach based on a quark-meson-diquark model using the
Functional Renormalization Group (FRG). We discuss the impact of perturbative
UV contributions, the inclusion of gauge field dynamics via a phenomenological
Polyakov loop potential, and the impact of matter backcoupling on the gauge
sector. The corresponding phase diagram including these effects is found to be
in qualitative agreement with recent lattice investigations.Comment: 8 pages, 9 figures; published versio
Event shapes in N=4 super-Yang-Mills theory

We study event shapes in N=4 SYM describing the angular distribution of
energy and R-charge in the final states created by the simplest half-BPS scalar
operator. Applying the approach developed in the companion paper
arXiv:1309.0769, we compute these observables using the correlation functions
of certain components of the N=4 stress-tensor supermultiplet: the half-BPS
operator itself, the R-symmetry current and the stress tensor. We present
master formulas for the all-order event shapes as convolutions of the Mellin
amplitude defining the correlation function of the half-BPS operators, with a
coupling-independent kernel determined by the choice of the observable. We find
remarkably simple relations between various event shapes following from N=4
superconformal symmetry. We perform thorough checks at leading order in the
weak coupling expansion and show perfect agreement with the conventional
calculations based on amplitude techniques. We extend our results to strong
coupling using the correlation function of half-BPS operators obtained from the
AdS/CFT correspondence.Comment: 52 pages, 6 figures; v2: typos correcte
Kinematic alignment of non-interacting CALIFA galaxies: Quantifying the
  impact of bars on stellar and ionised gas velocity field orientations

We present 80 stellar and ionised gas velocity maps from the Calar Alto
Legacy Integral Field Area (CALIFA) survey in order to characterize the
kinematic orientation of non-interacting galaxies. The study of galaxies in
isolation is a key step towards understanding how fast-external processes, such
as major mergers, affect kinematic properties in galaxies. We derived the
global and individual (projected approaching and receding sides) kinematic
position angles (PAs) for both the stellar and ionised gas line-of-sight
velocity distributions. When compared to the photometric PA, we find that
morpho-kinematic differences are smaller than 22 degrees in 90% of the sample
for both components; internal kinematic misalignments are generally smaller
than 16 degrees. We find a tight relation between the global stellar and
ionised gas kinematic PA consistent with circular-flow pattern motions in both
components. This relation also holds generally in barred galaxies across the
bar and galaxy disk scales. Our findings suggest that even in the presence of
strong bars, both the stellar and the gaseous components tend to follow the
gravitational potential of the disk. As a result, kinematic orientation can be
used to assess the degree of external distortions in interacting galaxies.Comment: Accepted for publication in A&
On "Graceful Exit" from inflationary phase in two-dimensional Liouville String Cosmology

Within the context of a super-critical (Liouville) string, we discuss (target-space) two-dimensional string cosmology. A numerical analysis indicates that the identification of time with the Liouville mode results in an expanding universe with matter which exhibits an inflationary phase, and `graceful exit' from it, tending asymptotically to a flat-metric fixed point.This fixed point is characterized by a dilaton configuration which, depending on the initial conditions, either decreases linearly with the cosmic time, or is a finite constant. This implies that, in contrast to the critical string case, the string coupling remains bounded during the exit from the inflationary phase, and, thus, the pertinent dynamics can be reliably described in terms of a tree-level string effective action. The rôle of matter in inducing such phenomena is emphasized. It is also interesting to note that the asymptotic value of the vacuum energy, which in the $\sigma$-model framework is identified with the `running' central charge deficit, depends crucially on the set of initial conditions. Thus, although preliminary, this toy model seems to share all the features expected to characterize a phenomenologically acceptable cosmological string model
Hydrodynamical simulations of the Sunyaev-Zel'dovich effect

We use a hydrodynamical N-body code to generate simulated maps, of size one square degree, of the thermal SZ effect. We study three different cosmologies; the currently-favoured low-density model with a cosmological constant, a critical-density model and a low-density open model. We stack simulation boxes corresponding to different redshifts in order to include contributions to the Compton y-parameter out to the highest necessary redshifts. Our main results are: 1. The mean y-distortion is around $4 \times 10^{-6}$ for low-density cosmologies, and $1 \times 10^{-6}$ for critical density. These are below current limits, but not by a wide margin in the former case. 2. In low-density cosmologies, the mean y-distortion comes from a broad range of redshifts, the bulk coming from $z < 2$ and a tail out to $z \sim 5$. For critical-density models, most of the contribution comes from $z < 1$. 3. The number of SZ sources above a given $y$ depends strongly on instrument resolution. For a one arcminute beam, there is around one source per square degree with $y > 10^{-5}$ in a critical-density Universe, and around 10 such sources per square degree in low-density models. Low-density models with and without a cosmological constant give very similar results. 4. We estimate that the {\sc Planck} satellite will be able to see of order 10^5 SZ sources if the Universe has a low density, or around 10^4 if it has critical density
Renormalization of the 1S0 One-Pion-Exchange NN Interaction in Presence
  of Derivative Contact Interactions

We use standard distorted wave theory techniques and dimensional
regularization to find out solutions of the nucleon-nucleon Lippman--Schwinger
equation with a kernel determined by the Weinberg's next-to-leading potential,
which consists of one--pion exchange and additional contact terms with
derivatives. Though for simplicity, we restrict the discussion to the $^1S_0$
channel and to contact terms containing up to two derivatives, the
generalization to higher waves and/or number of derivatives is straightforward.
The undetermined low energy constants emerging out of the renormalization
procedure are fitted to data.Comment: 7 pages, revtex4, Phys. Lett. B in prin
The two-loop helicity amplitudes for $q \bar q' \to V_1 V_2 \to
  4~\mathrm{leptons}$

We compute the two-loop massless QCD corrections to the helicity amplitudes
for the production of two massive vector bosons in quark-antiquark
annihilation, allowing for an arbitrary virtuality of the vector bosons: $q
\bar q' \to V_1V_2$. Combining with the leptonic decay currents, we obtain the
full two-loop QCD description of the corresponding electroweak four-lepton
production processes. The calculation is performed by projecting the two-loop
diagrams onto an appropriate basis of Lorentz structures. All two-loop Feynman
integrals are reduced to a basis of master integrals, which are then computed
using the differential equations method and optimised for numerical
performance. We provide a public C++ code which allows for fast and precise
numerical evaluations of the amplitudes.Comment: 34 pages, 3 figures, results available in computer readable format on
  HepForge at http://vvamp.hepforge.org ; fixed typos in electroweak coupling
  definitions, version accepted for publication in JHE
Coherent $\rho^0$ photoproduction in ultra-peripheral Pb-Pb collisions
  at $\mathbf{\sqrt{\textit{s}_{\rm NN}}} = 2.76$ TeV

We report the first measurement at the LHC of coherent photoproduction of
$\rho^0$ mesons in ultra-peripheral Pb-Pb collisions. The invariant mass and
transverse momentum distributions for $\rho^0$ production are studied in the
$\pi^+ \pi^-$ decay channel at mid-rapidity. The production cross section in
the rapidity range $|y|<0.5$ is found to be $\mathrm{d}\sigma/\mathrm{d}y = 425
\pm 10 \, (\mathrm{stat.})$ $^{+42}_{-50} \, (\mathrm{sys.})$ mb. Coherent
$\rho^0$ production is studied with and without requirement of nuclear breakup,
and the fractional yields for various breakup scenarios are presented. The
results are compared with those from lower energies and with model predictions.Comment: 23 pages, 6 captioned figures, 2 tables, authors from page 18,
  published version, figures at
  http://aliceinfo.cern.ch/ArtSubmission/node/156
Capture cross section measurements of (186,187,188)Os at n_TOF :
                    the resolved resonance region

The neutron capture cross sections of (186,187,188)Os have been measured at the CERN neutron time-of-flight facility, n_TOF, in the neutron energy range from 1 eV up to 1 MeV. In this contribution, we report the results of the analysis of the resolved resonance region (RRR). Resonance parameters have been extracted from a full R-matrix fit of the capture yields with the SAMMY code. A statistical analysis has been performed and the related average resonance parameters are derived. This information is crucial for a complete understanding and modeling in terms of the Hauser-Feshbach statistical model of the capture and inelastic reaction channels, required for the evaluation of the stellar reaction rates of these isotopes. Maxwellian average cross sections for the range of temperatures relevant for s-process nucleosynthesis have been derived from the combined information of the experimental data in the resolved and unresolved resonance regions. A brief account of the implications of this analysis in the estimation of the s-process component of the (187)Os abundance and the related impact on the estimates of the time-duration of the galactic nucleosynthesis through the Re/Os clock is given
The Herschel view of the dominant mode of galaxy growth from z=4 to the present day

We present an analysis of the deepest Herschel images in four major extragalactic fields GOODS-North, GOODS-South, UDS and COSMOS obtained within the GOODS-Herschel and CANDELS-Herschel key programs. The picture provided by 10497 individual far-infrared detections is supplemented by the stacking analysis of a mass-complete sample of 62361 star-forming galaxies from the CANDELS-HST H band-selected catalogs and from two deep ground-based Ks band-selected catalogs in the GOODS-North and the COSMOS-wide fields, in order to obtain one of the most accurate and unbiased understanding to date of the stellar mass growth over the cosmic history. We show, for the first time, that stacking also provides a powerful tool to determine the dispersion of a physical correlation and describe our method called "scatter stacking" that may be easily generalized to other experiments. We demonstrate that galaxies of all masses from z=4 to 0 follow a universal scaling law, the so-called main sequence of star-forming galaxies. We find a universal close-to-linear slope of the logSFR-logM* relation with evidence for a flattening of the main sequence at high masses (log(M*/Msun) > 10.5) that becomes less prominent with increasing redshift and almost vanishes by z~2. This flattening may be due to the parallel stellar growth of quiescent bulges in star-forming galaxies. Within the main sequence, we measure a non varying SFR dispersion of 0.3 dex. The specific SFR (sSFR=SFR/M*) of star-forming galaxies is found to continuously increase from z=0 to 4. Finally we discuss the implications of our findings on the cosmic SFR history and show that more than 2/3 of present-day stars must have formed in a regime dominated by the main sequence mode. As a consequence we conclude that, although omnipresent in the distant Universe, galaxy mergers had little impact in shaping the global star formation history over the last 12.5 Gyr
Server power modeling for run-time energy optimization of cloud computing facilities

As advanced Cloud services are becoming mainstream, the contribution of data centers in the overall power consumption of modern cities is growing dramatically. The average consumption of a single data center is equivalent to the energy consumption of 25.000 households. Modeling the power consumption for these infrastructures is crucial to anticipate the effects of aggressive optimization policies, but accurate and fast power modeling is a complex challenge for high-end servers not yet satisfied by analytical approaches. This work proposes an automatic method, based on Multi-Objective Particle Swarm Optimization, for the identification of power models of enterprise servers in Cloud data centers. Our approach, as opposed to previous procedures, does not only consider the workload consolidation for deriving the power model, but also incorporates other non traditional factors like the static power consumption and its dependence with temperature. Our experimental results shows that we reach slightly better models than classical approaches, but simul- taneously simplifying the power model structure and thus the numbers of sensors needed, which is very promising for a short-term energy prediction. This work, validated with real Cloud applications, broadens the possibilities to derive efficient energy saving techniques for Cloud facilities