Uncertainty about the Persistence of Cost-Push Shocks and the Optimal Reaction of the Monetary Authority.

In this paper we formalize the uncertainty about the persistence of cost-push shocks using an open economy optimal control model with Markov regime-switching and robust control. The latter is used in only one of the regimes producing relatively more persistent cost-push shocks in that regime. Conditional on being in the regime with relatively less persistence, we obtain two main results: a) underestimating the probability of switching to the regime with relatively more persistent cost-push shocks causes higher welfare losses than its overestimation; and b) the welfare losses associated with either underestimation or overestimation of such probability increase with the size of the penalty on inflation deviations from its target. Keywords: Model uncertainty, Robustness, Markov regime-switching, Monetary policy, Inflation targeting.Model uncertainty, Robustness, Markov regime-switching, Monetary policy, Inflation targeting

A search for new hot subdwarf stars by means of Virtual Observatory tools

Hot subdwarf stars are faint, blue objects, and are the main contributors to the far-UV excess observed in elliptical galaxies. They offer an excellent laboratory to study close and wide binary systems, and to scrutinize their interiors through asteroseismology, as some of them undergo stellar oscillations. However, their origins are still uncertain, and increasing the number of detections is crucial to undertake statistical studies. In this work, we aim at defining a strategy to find new, uncatalogued hot subdwarfs. Making use of Virtual Observatory tools we thoroughly search stellar catalogues to retrieve multi-colour photometry and astrometric information of a known sample of blue objects, including hot subdwarfs, white dwarfs, cataclysmic variables and main sequence OB stars. We define a procedure to discriminate among these spectral classes, particularly designed to obtain a hot subdwarf sample with a low contamination factor. In order to check the validity of the method, this procedure is then applied to two test sky regions: the Kepler FoV and to a test region of around (RA:225, DEC:5) deg. As a result, we obtained 38 hot subdwarf candidates, 23 of which had already a spectral classification. We have acquired spectroscopy for three other targets, and four additional ones have an available SDSS spectrum, which we used to determine their spectral type. A temperature estimate is provided for the candidates based on their spectral energy distribution, considering two-atmospheres fit for objects with clear infrared excess. Eventually, out of 30 candidates with spectral classification, 26 objects were confirmed to be hot subdwarfs, yielding a contamination factor of only 13%. The high rate of success demonstrates the validity of the proposed strategy to find new uncatalogued hot subdwarfs. An application of this method to the entire sky will be presented in a forthcoming work.Comment: 13 pages, 7 figure

Deep into the Water Fountains: The case of IRAS 18043-2116

(Abridged) The formation of large-scale (hundreds to few thousands of AU) bipolar structures in the circumstellar envelopes (CSEs) of post-Asymptotic Giant Branch (post-AGB) stars is poorly understood. The shape of these structures, traced by emission from fast molecular outflows, suggests that the dynamics at the innermost regions of these CSEs does not depend only on the energy of the radiation field of the central star. Deep into the Water Fountains is an observational project based on the results of programs carried out with three telescope facilities: The Karl G. Jansky Very Large Array (JVLA), The Australia Telescope Compact Array (ATCA), and the Very Large Telescope (SINFONI-VLT). Here we report the results of the observations towards the WF nebula IRAS 18043$-$2116: Detection of radio continuum emission in the frequency range 1.5GHz - 8.0GHz; H$_{2}$O maser spectral features and radio continuum emission detected at 22GHz, and H$_{2}$ ro-vibrational emission lines detected at the near infrared. The high-velocity H$_{2}$O maser spectral features, and the shock-excited H$_{2}$ emission detected could be produced in molecular layers which are swept up as a consequence of the propagation of a jet-driven wind. Using the derived H$_{2}$ column density, we estimated a molecular mass-loss rate of the order of $10^{-9}$M$_{\odot}$yr$^{-1}$. On the other hand, if the radio continuum flux detected is generated as a consequence of the propagation of a thermal radio jet, the mass-loss rate associated to the outflowing ionized material is of the order of 10$^{-5}$M$_{\odot}$yr$^{-1}$. The presence of a rotating disk could be a plausible explanation for the mass-loss rates estimated.Comment: 10 pages, 5 figures. Accepted for publication in A&

Mean field study of structural changes in Pt isotopes with the Gogny interaction

The evolution of the nuclear shapes along the triaxial landscape is studied in the Pt isotopic chain using the selfconsistent Hartree-Fock-Bogoliubov approximation based on the Gogny interaction. In addition to the parametrization D1S, the new incarnations D1N and D1M of this force are also included in our analysis to asses to which extent the predictions are independent of details of the effective interaction. The considered range of neutron numbers 88<N<26 includes prolate, triaxial, oblate and spherical ground state shapes and serves for a detailed comparison of the predictions obtained with the new sets D1N and D1M against the ones provided by the standard parametrization Gogny-D1S in a region of the nuclear landscape for which experimental and theoretical fingerprints of shape transitions have been found. Structural evolution along the Pt chain is discussed in terms of the deformation dependence of single particle energies.Comment: 18 pages, 10 figures. Accepted for publication in Phys. Rev.

Formation of a heterometallic Al^III/Sm^III complex involving a novel [EtAl(2-py)<inf>2</inf>O]^2- ligand (2-py = 2-pyridyl)

Controlled O2-oxidation of the Sm(II) sandwich compound [{EtAl(2-py)3}2Sm] (1a) gives the Sm(III)/Al(III) compound [{EtAl(2-py)3}{EtAl(2-py)2O}Sm]2 (2), containing the novel multifunctional dianionic ligand [EtAl(2-py)2O]2-. The formation of an O-bridged Al-O-Sm arrangement in the structure of 2 is potentially relevant to the catalytic epoxidation of styrene with dry air using heterobimetallic sandwich compounds like 1a.We gratefully acknowledge the EU (Marie Curie Intra European Fellowship within the 7th European Community Framework Programme for R.G.-R., Advanced Investigator Award for D.S.W., studentship for H.R.S.).This is the author accepted manuscript. The final version is available from ACS at https://pubs.acs.org/doi/abs/10.1021/om5009132

La erosión en campos cultivados en Galicia (NW España)

[Resumen] En la presente comunicación se realiza un seguimiento de la erosión en parcelas cultivadas en Galicia. Para ello, en la estación experimental El Pedroso se construyeron dos parcelas, de diferente pendiente, y se sometieron a un proceso de laboreo según las formas tradicionales de cultivar. En la presente comunicación se exponen los resultados del seguimiento de la experimentación desde abril a diciembre de 1995, en donde se observa que la pendiente desempeña una función distinta de la que en un principio podría pensarse, dado que la escorrentía y carga varían de forma inversa a la pendiente.[Abstract] A very closed study of erosion is made in this paper about plough plots in Galicia. For this, in the experimental station El Pedroso were built two plots, with different slope, and were ploughed in a traditional way. In this paper we resume the results of the experiment from april to december 1995, where it is seen that slope has a different function that was thought at the beginning of the experiment, because discharge and load don't vary directly with slope

A three-dimensional view of the remnant of Nova Persei 1901 (GK Per)

We present a kinematical study of the optical ejecta of GK Per. It is based on proper motions measurements of 282 knots from ~20 images spanning 25 years. Doppler-shifts are also computed for 217 knots. The combination of proper motions and radial velocities allows a unique 3-D view of the ejecta to be obtained. The main results are: (1) the outflow is a thick shell in which knots expand with a significant range of velocities, mostly between 600 and 1000 km/s; (2) kinematical ages indicate that knots have suffered only a modest deceleration since their ejection a century ago; (3) no evidence for anisotropy in the expansion rate is found; (4) velocity vectors are generally aligned along the radial direction but a symmetric pattern of non-radial velocities is also observed at specific directions; (5) the total Halpha+[NII] flux has been linearly decreasing at a rate of 2.6 % per year in the last decade. The Eastern nebular side is fading at a slower rate than the Western one. Some of the knots displayed a rapid change of brightness during the 2004-2011 period. Over a longer timescale, a progressive circularization and homogenization of the nebula is taking place; (6) a kinematic distance of 400+-30 pc is determined. These results raise some problems to the previous interpretations of the evolution of GK Per. In particular, the idea of a strong interaction of the outflow with the surrounding medium in the Southwest quadrant is not supported by our data.Comment: Accepted for publication in The Astrophysical Journal (19 pages, 17 figures). Higher resolution version of this article (2.5 MB) is available at http://www.aai.ee/~sinope/ApJ89291_liimets.pd