Constraining the mass of the planet(s) sculpting a disk cavity. The intriguing case of 2MASS J16042165-2130284

The large cavities observed in the dust and gas distributions of transition disks may be explained by planet-disk interactions. At ~145 pc, 2MASS J16042165-2130284 (J1604) is a 5-12 Myr old transitional disk with different gap sizes in the mm- and $\mu$m-sized dust distributions (outer edges at ~79 and at ~63 au, respectively). Its $^{12}$CO emission shows a ~30 au cavity. This radial structure suggests that giant planets are sculpting this disk. We aim to constrain the masses and locations of plausible giant planets around J1604. We observed J1604 with the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) at the Very Large Telescope (VLT), in IRDIFS\_EXT, pupil-stabilized mode, obtaining YJH- band images with the integral field spectrograph (IFS) and K1K2-band images with the Infra-Red Dual-beam Imager and Spectrograph (IRDIS). The dataset was processed exploiting the angular differential imaging (ADI) technique with high-contrast algorithms. Our observations reach a contrast of $\Delta K, YH$ ~12 mag from 0.15" to 0.80" (~22 to 115 au), but no planet candidate is detected. The disk is directly imaged in scattered light at all bands from Y to K, and it shows a red color. This indicates that the dust particles in the disk surface are mainly $\gtrsim0.3\,\mu$m-sized grains. We confirm the sharp dip/decrement in scattered light in agreement with polarized light observations. Comparing our images with a radiative transfer model we argue that the southern side of the disk is most likely the nearest. This work represents the deepest search yet for companions around J1604. We reach a mass sensitivity of $\gtrsim 2-3M_{Jup}$ from ~22 to ~115 au according to a hot start scenario. We propose that a brown dwarf orbiting inside of ~15 au and additional Jovian planets at larger radii could account for the observed properties of J1604 while explaining our lack of detection.Comment: 10 pages, 7 Figures. Accepted for publication in A&A . Abridged abstrac

Reducción del consumo eléctrico debido a climatización en un salón de un edificio educativo del NEA

La sociedad actual demanda condiciones de confort que permitan desarrollar actividades con elevada productividad, en el NEA alcanzar las condiciones apropiadas de temperatura y humedad en edificios antiguos implica un excesivo consumo de energía eléctrica. Se presenta la simulación computacional mediante el software Energy Plus del comportamiento térmico de un aula del edificio de la Facultad Regional Resistencia de la Universidad Tecnológica Nacional. Se validan los resultados de la simulación con datos experimentales de temperatura interior para idénticas condiciones exteriores de radiación solar y temperatura. Se obtiene la carga térmica instantánea y la disminución potencial de consumo de energía eléctrica destinada a la climatización para diferentes casos de rehabilitación térmica del salón. Se verifica la exactitud del modelo confrontando los resultados de la simulación con los datos internos medidos en el aula. Se demuestra también la capacidad del software como herramienta para mejorar la eficiencia energética de edificios y garantizar las condiciones de confort.Today’s society demands high comfort conditions to carry out activities with high productivity, in the Argentine Northeast achieving the appropriate conditions of temperature and humidity in old buildings involves excessive power consumption. It is presented the computer simulation by the Energy Plus software about thermal behavior of a classroom in the building of the Facultad Regional Resistencia of the Universidad Tecnológica Nacional. The simulation results are validated with measured data of indoor temperature for the same exterior conditions of solar radiation and temperature. Is obtained the instantaneous thermal charge and the decrease of potential consumption of electricity for air conditioning in different cases of thermal rehabilitation. The accuracy of the model is verified by comparing the simulation results with internal data measured in the classroom. The ability of the software as a tool to improve the energy efficiency of buildings and ensure comfort conditions is also demonstrated.Tema 8: Energías renovables, modelización y simulación.Facultad de Arquitectura y Urbanism

Reducción del consumo eléctrico debido a climatización en un salón de un edificio educativo del NEA

La sociedad actual demanda condiciones de confort que permitan desarrollar actividades con elevada productividad, en el NEA alcanzar las condiciones apropiadas de temperatura y humedad en edificios antiguos implica un excesivo consumo de energía eléctrica. Se presenta la simulación computacional mediante el software Energy Plus del comportamiento térmico de un aula del edificio de la Facultad Regional Resistencia de la Universidad Tecnológica Nacional. Se validan los resultados de la simulación con datos experimentales de temperatura interior para idénticas condiciones exteriores de radiación solar y temperatura. Se obtiene la carga térmica instantánea y la disminución potencial de consumo de energía eléctrica destinada a la climatización para diferentes casos de rehabilitación térmica del salón. Se verifica la exactitud del modelo confrontando los resultados de la simulación con los datos internos medidos en el aula. Se demuestra también la capacidad del software como herramienta para mejorar la eficiencia energética de edificios y garantizar las condiciones de confort.Today’s society demands high comfort conditions to carry out activities with high productivity, in the Argentine Northeast achieving the appropriate conditions of temperature and humidity in old buildings involves excessive power consumption. It is presented the computer simulation by the Energy Plus software about thermal behavior of a classroom in the building of the Facultad Regional Resistencia of the Universidad Tecnológica Nacional. The simulation results are validated with measured data of indoor temperature for the same exterior conditions of solar radiation and temperature. Is obtained the instantaneous thermal charge and the decrease of potential consumption of electricity for air conditioning in different cases of thermal rehabilitation. The accuracy of the model is verified by comparing the simulation results with internal data measured in the classroom. The ability of the software as a tool to improve the energy efficiency of buildings and ensure comfort conditions is also demonstrated.Tema 8: Energías renovables, modelización y simulación.Facultad de Arquitectura y Urbanism

Reducción del consumo eléctrico debido a climatización en un salón de un edificio educativo del NEA

La sociedad actual demanda condiciones de confort que permitan desarrollar actividades con elevada productividad, en el NEA alcanzar las condiciones apropiadas de temperatura y humedad en edificios antiguos implica un excesivo consumo de energía eléctrica. Se presenta la simulación computacional mediante el software Energy Plus del comportamiento térmico de un aula del edificio de la Facultad Regional Resistencia de la Universidad Tecnológica Nacional. Se validan los resultados de la simulación con datos experimentales de temperatura interior para idénticas condiciones exteriores de radiación solar y temperatura. Se obtiene la carga térmica instantánea y la disminución potencial de consumo de energía eléctrica destinada a la climatización para diferentes casos de rehabilitación térmica del salón. Se verifica la exactitud del modelo confrontando los resultados de la simulación con los datos internos medidos en el aula. Se demuestra también la capacidad del software como herramienta para mejorar la eficiencia energética de edificios y garantizar las condiciones de confort.Today’s society demands high comfort conditions to carry out activities with high productivity, in the Argentine Northeast achieving the appropriate conditions of temperature and humidity in old buildings involves excessive power consumption. It is presented the computer simulation by the Energy Plus software about thermal behavior of a classroom in the building of the Facultad Regional Resistencia of the Universidad Tecnológica Nacional. The simulation results are validated with measured data of indoor temperature for the same exterior conditions of solar radiation and temperature. Is obtained the instantaneous thermal charge and the decrease of potential consumption of electricity for air conditioning in different cases of thermal rehabilitation. The accuracy of the model is verified by comparing the simulation results with internal data measured in the classroom. The ability of the software as a tool to improve the energy efficiency of buildings and ensure comfort conditions is also demonstrated.Tema 8: Energías renovables, modelización y simulación.Facultad de Arquitectura y Urbanism

Monotonicity of quantum ground state energies: Bosonic atoms and stars

The N-dependence of the non-relativistic bosonic ground state energy is studied for quantum N-body systems with either Coulomb or Newton interactions. The Coulomb systems are "bosonic atoms," with their nucleus fixed, and the Newton systems are "bosonic stars". In either case there exists some third order polynomial in N such that the ratio of the ground state energy to the respective polynomial grows monotonically in N. Some applications of these new monotonicity results are discussed

Exploring dust around HD142527 down to 0.025" / 4au using SPHERE/ZIMPOL

We have observed the protoplanetary disk of the well-known young Herbig star HD 142527 using ZIMPOL Polarimetric Differential Imaging with the VBB (Very Broad Band, ~600-900nm) filter. We obtained two datasets in May 2015 and March 2016. Our data allow us to explore dust scattering around the star down to a radius of ~0.025" (~4au). The well-known outer disk is clearly detected, at higher resolution than before, and shows previously unknown sub-structures, including spirals going inwards into the cavity. Close to the star, dust scattering is detected at high signal-to-noise ratio, but it is unclear whether the signal represents the inner disk, which has been linked to the two prominent local minima in the scattering of the outer disk, interpreted as shadows. An interpretation of an inclined inner disk combined with a dust halo is compatible with both our and previous observations, but other arrangements of the dust cannot be ruled out. Dust scattering is also present within the large gap between ~30 and ~140au. The comparison of the two datasets suggests rapid evolution of the inner regions of the disk, potentially driven by the interaction with the close-in M-dwarf companion, around which no polarimetric signal is detected.Comment: 11 pages, 7 figures, accepted for publication in A

The gravitational mass of Proxima Centauri measured with SPHERE from a microlensing event

Proxima Centauri, our closest stellar neighbour, is a low-mass M5 dwarf orbiting in a triple system. An Earth-mass planet with an 11 day period has been discovered around this star. The star's mass has been estimated only indirectly using a mass-luminosity relation, meaning that large uncertainties affect our knowledge of its properties. To refine the mass estimate, an independent method has been proposed: gravitational microlensing. By taking advantage of the close passage of Proxima Cen in front of two background stars, it is possible to measure the astrometric shift caused by the microlensing effect due to these close encounters and estimate the gravitational mass of the lens (Proxima Cen). Microlensing events occurred in 2014 and 2016 with impact parameters, the closest approach of Proxima Cen to the background star, of 1\farcs6 $\pm$ 0\farcs1 and 0\farcs5 $\pm$ 0\farcs1, respectively. Accurate measurements of the positions of the background stars during the last two years have been obtained with HST/WFC3, and with VLT/SPHERE from the ground. The SPHERE campaign started on March 2015, and continued for more than two years, covering 9 epochs. The parameters of Proxima Centauri's motion on the sky, along with the pixel scale, true North, and centering of the instrument detector were readjusted for each epoch using the background stars visible in the IRDIS field of view. The experiment has been successful and the astrometric shift caused by the microlensing effect has been measured for the second event in 2016. We used this measurement to derive a mass of 0.150$^{\textrm{+}0.062}_{-0.051}$ (an error of $\sim$ 40\%) \MSun for Proxima Centauri acting as a lens. This is the first and the only currently possible measurement of the gravitational mass of Proxima Centauri.Comment: 10 pages, 6 figures, accepted by MNRA

ALMA observations of Elias 2–24: a protoplanetary disk with multiple gaps in the Ophiuchus molecular cloud

We present ALMA 1.3 mm continuum observations at 0. 2 (25 au) resolution of Elias 2–24, one of the largest and brightest protoplanetary disks in the Ophiuchus Molecular Cloud, and we report the presence of three partially resolved concentric gaps located at ∼20, 52, and 87 au from the star. We perform radiative transfer modeling of the disk to constrain its surface density and temperature radial profile and place the disk structure in the context of mechanisms capable of forming narrow gaps such as condensation fronts and dynamical clearing by actively forming planets. In particular, we estimate the disk temperature at the locations of the gaps to be 23, 15, and 12 K (at 20, 52, and 87 au, respectively), very close to the expected snowlines of CO (23–28 K) and N2 (12–15 K). Similarly, by assuming that the widths of the gaps correspond to 4–8× the Hill radii of forming planets (as suggested by numerical simulations), we estimate planet masses in the range of 0.2 1.5 – MJup, 1.0 8.0 – MJup, and 0.02 0.15 – MJup for the inner, middle, and outer gap, respectively. Given the surface density profile of the disk, the amount of “missing mass” at the location of each one of these gaps (between 4 and 20 MJup) is more than sufficient to account for the formation of such planets.Fil: Cieza, Lucas A.. Universidad Diego Portales; ChileFil: Casassus, Simon. Universidad de Chile; ChileFil: Pérez, Sebastian. Universidad de Chile; ChileFil: Hales, Antonio. Alma Observatory; ChileFil: Cárcamo, Miguel. Universidad de Chile; ChileFil: Ansdell, Megan. University of California at Berkeley; Estados UnidosFil: Avenhaus, Henning. Universitat Zurich; SuizaFil: Bayo, Amelia. Universidad de Valparaiso; ChileFil: Bertrang, Gesa H.-M.. Universidad Diego Portales; ChileFil: Cánovas, Hector. Agencia Espacial Europea; EspañaFil: Christiaens, Valentin. Universidad de Chile; ChileFil: Dent, William. Alma Observatory; ChileFil: Ferrero, Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Gamen, Roberto Claudio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Olofsson, Johan. Universidad de Valparaiso; ChileFil: Orcajo, Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Osses, Axel. Universidad de Chile; ChileFil: Peña Ramirez, Karla. Universidad de Antofagasta; ChileFil: Principe, David. Massachusetts Institute of Technology; Estados UnidosFil: Ruíz Rodríguez, Dary. Rochester Institute Of Technology; Estados UnidosFil: Schreiber, Matthias R.. Universidad de Valparaiso; ChileFil: Plas, Gerrit van der. Univ. Grenoble Alpes; SuizaFil: Williams, Jonathan P.. Institute For Astronomy, University Of Hawaii; Estados UnidosFil: Zurlo, Alice. Universidad Diego Portales; Chil

Evidence For The Production Of Slow Antiprotonic Hydrogen In Vacuum

We present evidence showing how antiprotonic hydrogen, the quasistable antiproton-proton (pbar-p) bound system, has been synthesized following the interaction of antiprotons with the hydrogen molecular ion (H2+) in a nested Penning trap environment. From a careful analysis of the spatial distributions of antiproton annihilation events, evidence is presented for antiprotonic hydrogen production with sub-eV kinetic energies in states around n=70, and with low angular momenta. The slow antiprotonic hydrogen may be studied using laser spectroscopic techniques.Comment: 5 pages with 4 figures. Published as Phys. Rev. Letters 97, 153401 (2006), in slightly different for