Optical and IR Photometry of Globular Clusters in NGC1399: Evidence for Color-Metallicity Nonlinearity

We combine new Wide Field Camera~3 IR Channel (WFC3/IR) F160W (H) imaging data for NGC1399, the central galaxy in the Fornax cluster, with archival F475W (g), F606W (V), F814W (I), and F850LP (z) optical data from the Advanced Camera for Surveys (ACS). The purely optical g-I, V-I, and g-z colors of NGC1399's rich globular cluster (GC) system exhibit clear bimodality, at least for magnitudes $I_814 > 21.5$. The optical-IR I-H color distribution appears unimodal, and this impression is confirmed by mixture modeling analysis. The V-H colors show marginal evidence for bimodality, consistent with bimodality in V-I and unimodality in I-H. If bimodality is imposed for I-H with a double Gaussian model, the preferred blue/red split differs from that for optical colors; these "differing bimodalities" mean that the optical and optical-IR colors cannot both be linearly proportional to metallicity. Consistent with the differing color distributions, the dependence of I-H on g-I for the matched GC sample is significantly nonlinear, with an inflection point near the trough in the g-I color distribution; the result is similar for the I-H dependence on g-z colors taken from the ACS Fornax Cluster Survey. These g-z colors have been calibrated empirically against metallicity; applying this calibration yields a continuous, skewed, but single-peaked metallicity distribution. Taken together, these results indicate that nonlinear color-metallicity relations play an important role in shaping the observed bimodal distributions of optical colors in extragalactic GC systems.Comment: 15 pages, 12 figures, accepted for publication in the Astrophysical Journa

Short Photoluminescence Lifetimes Linked to Crystallite Dimensions, Connectivity, and Perovskite Crystal Phases

Time-correlated single photon counting has been conducted to gain further insights into the short photoluminescence lifetimes (nanosecond) of lead iodide perovskite (MAPbI3) thin films (~100 nm). We analyze three different morphologies, compact layer, isolated island, and connected large grain films, from 14 to 300 K using a laser excitation power of 370 nJ/cm2. Lifetime fittings from the Generalized Berberan-Santos decay model range from 0.5 to 6.5 ns, pointing to quasi-direct bandgap emission despite the three different sample strains. The high energy band emission for the isolated-island morphology shows fast recombination rate centers up to 4.8 ns-1, compared to the less than 2 ns-1for the other two morphologies, similar to that expected in a good quality single crystal of MAPbI3. Low-temperature measurements on samples reflect a huge oscillator strength in this material where the free exciton recombination dominates, explaining the fast lifetimes, the low thermal excitation, and the thermal escape obtained. © 2022 American Chemical Society. All rights reserved

N_0 completions on partial matrices

An $n\times n$ matrix is called an $N_0$-matrix if all its principal minors are nonpositive. In this paper, we are interested in $N_0$-matrix completion problems, that is, when a partial $N_0$-matrix has an $N_0$-matrix completion. In general, a combinatorially or non-combinatorially symmetric partial $N_0$-matrix does not have an $N_0$-matrix completion. Here, we prove that a combinatorially symmetric partial $N_0$-matrix, with no null main diagonal entries, has an $N_0$-matrix completion if the graph of its specified entries is a 1-chordal graph or a cycle. We also analyze the mentioned problem when the partial matrix has some null main diagonal entries.Fundação para a Ciência e a Tecnologia(FCT) através do programa POCTISpanish DGI grant number MTM2007-6447

Evolución de las tendencias profesionales del titulado en educación física y en ciencias de la actividad física y del deporte desde 1975 hasta la actualidad

En este artículo exponemos como han evolucionado las tendencias y salidas profesionales de los profesionales de la educación física desde los estudios de los diferentes autores que han intentado aportar una visión sobre la cuestión. Desde el primer estudio de Mestre (1975), hasta la actualidad, han surgido diferentes investigaciones en este campo, que han analizado el perfil profesional en base a las demandas laborables, finalizando en las aportaciones del European Network of Sport Sciences Institutes (1999). A modo de conclusión y tras la exposición efectuada, se han elaborado unas directrices acerca de las líneas futuras que regirán el campo laboral en nuestra profesión de las que destacamos la inexistencia de regulación profesional y la trascendencia que ha adquirido en nuestros días la práctica del deporte, que aconsejan y justifican plenamente la necesidad de una regulación completa y sistemática con el rango normativo exigido por el art. 36 de la norma constitucional

Stellar proper motion and the timing of planetary transits

Duration and period of transits in extrasolar planetary systems can exhibit long-term variations for a variety of reasons. Here we investigate how systemic proper motion, which steadily re-orients planetary orbit with respect to our line of sight, affects the timing of transits. We find that in a typical system with a period of several days proper motion at the level of 100 mas/yr makes transit duration vary at a rate ~10-100 ms/yr. In some isolated systems this variation is at the measurable level (can be as high as 0.6 s/yr for GJ436) and may exceed all other transit timing contributions (due to the general relativity, stellar quadrupole, etc.). In addition, proper motion causes evolution of the observed orbital period via the Shklovskii effect at a rate $\gtrsim 10$ $\mu$s/yr for the nearby transiting systems (0.26 ms/yr in GJ436), which in some cases exceeds all other contributions to $\dot P$. Earth's motion around the Sun gives rise to additional periodic timing signal (even for systems with zero intrinsic proper motion) allowing a full determination of the spatial orientation of the planetary orbit. Unlike most other timing effects the proper motion signatures persist even in systems with zero eccentricity and get stronger as the planetary period increases. They should be the dominant cause of transit timing variations in isolated wide separation (periods of months) systems that will be sought by Kepler.Comment: 7 pages, 2 tables, submitted to Ap

Four new planets around giant stars and the mass-metallicity correlation of planet-hosting stars

CONTEXT. Exoplanet searches have demonstrated that giant planets are preferentially found around metal-rich stars and that their fraction increases with the stellar mass. AIMS. During the past six years, we have conducted a radial velocity follow-up program of 166 giant stars, to detect substellar companions, and characterizing their orbital properties. Using this information, we aim to study the role of the stellar evolution in the orbital parameters of the companions, and to unveil possible correlations between the stellar properties and the occurrence rate of giant planets. METHODS. Using FEROS and CHIRON spectra, we have computed precision radial velocities and we have derived atmospheric and physical parameters for all of our targets. Additionally, velocities computed from UCLES spectra are presented here. By studying the periodic radial velocity signals, we have detected the presence of several substellar companions. RESULTS. We present four new planetary systems around the giant stars HIP8541, HIP74890, HIP84056 and HIP95124. Additionally, we find that giant planets are more frequent around metal-rich stars, reaching a peak in the detection of $f$ = 16.7$^{+15.5}_{-5.9}$% around stars with [Fe/H] $\sim$ 0.35 dex. Similarly, we observe a positive correlation of the planet occurrence rate with the stellar mass, between M$_\star$ $\sim$ 1.0 -2.1 M$_\odot$, with a maximum of $f$ = 13.0$^{+10.1}_{-4.2}$%, at M$_\star$ = 2.1 M$_\odot$. CONCLUSIONS. We conclude that giant planets are preferentially formed around metal-rich stars. Also, we conclude that they are more efficiently formed around more massive stars, in the mass range of M$_\star$ $\sim$ 1.0 - 2.1 M$_\odot$. These observational results confirm previous findings for solar-type and post-MS hosting stars, and provide further support to the core-accretion formation model.Comment: Accepted for publication in A&

Globular cluster systems in fossil groups: NGC6482, NGC1132 and ESO306-017

We study the globular cluster (GC) systems in three representative fossil group galaxies: the nearest (NGC6482), the prototype (NGC1132) and the most massive known to date (ESO306-017). This is the first systematic study of GC systems in fossil groups. Using data obtained with the Hubble Space Telescope Advanced Camera for Surveys in the F475W and F850LP filters, we determine the GC color and magnitude distributions, surface number density profiles, and specific frequencies. In all three systems, the GC color distribution is bimodal, the GCs are spatially more extended than the starlight, and the red population is more concentrated than the blue. The specific frequencies seem to scale with the optical luminosities of the central galaxy and span a range similar to that of the normal bright elliptical galaxies in rich environments. We also analyze the galaxy surface brightness distributions to look for deviations from the best-fit S\'ersic profiles; we find evidence of recent dynamical interaction in all three fossil group galaxies. Using X-ray data from the literature, we find that luminosity and metallicity appear to correlate with the number of GCs and their mean color, respectively. Interestingly, although NGC6482 has the lowest mass and luminosity in our sample, its GC system has the reddest mean color, and the surrounding X-ray gas has the highest metallicity.Comment: 16 pages, 13 figures. Accepted for publication in A&

Decision making and skill development In youth football players

Este artículo presenta como se desarrolla la toma de decisiones y la habilidad técnica en jugadores con alto nivel de pericia desde los 6-7 a 13-14 años. El marco teórico está basado en la perspectiva de los sistemas dinámicos y la enseñanza comprensiva de los deportes. Se tomó como muestra a 57 jugadores del primer equipo de cada categoría de edad del Albacete Balompié: prebenjamín, benjamín, alevín e infantil. El instrumento usado fue la Herramienta de Evaluación del Rendimiento de Juego (HERJ), que mide la toma de decisiones y la ejecución, incluyendo el análisis ecológico atendiendo a principios tácticos (Bayer, 1992), comparando la situación en el juego con la decisión aplicada. Los resultados se basan en el análisis inferencial y correlacional. La evolución del rendimiento de juego se orienta desde el ataque hasta la defensa. Se han encontrado diferencias significativas en las variables entre las cuatro categorías de formación estudiadas, especialmente en el principio táctico de progresar hacia la portería contraria y en el desmarque, así como en el marcaje y la ayuda en defensa.This paper presents how decision-making and skills are developed in high level of expertise players from 6-7 to 13-14 years. The framework is based on the dynamical systems and teaching games for understanding approaches. Participants were 57 first team players of each age (n = 13 to 16) of Albacete Balompié: U-8, U-10, U-12 and U-14. The Game Performance Assessment Tool (GPET) was the instrument used for assessment, which measures decision-making and execution from an ecological view in relation to tactical principles (Bayer, 1992), comparing the game situation with the decision applied. The results are based on inferential and correlation analysis. The evolution of knowledge evolves attack to defensive. We have found significant differences in variables between the four age categories studied. These differences have been shown in attack: the progress toward goal tactical principle and shake off; on defence: marking and cover (off-ball defenders)