Returning magnetic flux in sunspot penumbrae

We study the presence of reversed polarity magnetic flux in sunspot penumbra. We applied a new regularized method to deconvolve spectropolarimetric data observed with the spectropolarimeter SP onboard Hinode. The new regularization is based on a principal component decomposition of the Stokes profiles. The resulting Stokes profiles were inverted to infer the magnetic field vector using SIR. We find, for the first time, reversed polarity fields at the border of many bright penumbral filaments in the whole penumbra.Comment: 5 pages, 5 figures, accepted for publication in A&A Letter

Spatial deconvolution of spectropolarimetric data: an application to quiet Sun magnetic elements

Observations of the Sun from the Earth are always limited by the presence of the atmosphere, which strongly disturbs the images. A solution to this problem is to place the telescopes in space satellites, which produce observations without any (or limited) atmospheric aberrations. However, even though the images from space are not affected by atmospheric seeing, the optical properties of the instruments still limit the observations. In the case of diffraction limited observations, the PSF establishes the maximum allowed spatial resolution, defined as the distance between two nearby structures that can be properly distinguished. In addition, the shape of the PSF induce a dispersion of the light from different parts of the image, leading to what is commonly termed as stray light or dispersed light. This effect produces that light observed in a spatial location at the focal plane is a combination of the light emitted in the object at relatively distant spatial locations. We aim to correct the effect produced by the telescope's PSF using a deconvolution method, and we decided to apply the code on Hinode/SP quiet Sun observations. We analyze the validity of the deconvolution process with noisy data and we infer the physical properties of quiet Sun magnetic elements after the deconvolution process.Comment: 14 pages, 9 figure

Políticas de imigração, integração, e cidadania em Portugal: o caso da saúde no século XXI

This article investigates to what extent immigration is confronting the Welfare States with citizenship limitations as citizenship has been called into question by immigration, globalization, and the increasing internal debate of political communities. This case study of immigration in Portugal examines the contradiction between the rhetoric of immigrant integration portrayed by the State and the reality of immigrant exclusion. Existing research highlights the importance of international human rights frameworks as a catalyst for governments’ recognition of immigrants’ social rights. The study of Portuguese immigration policy on which this article is based was undertaken as a way to explore such apparent contradictions. As a Southern European country that has undergone an enormous political and economic transformation in the last three decades, experiencing the contradictions of advanced capitalist societies in an intensified way, Portugal offers an interesting case study for such analysis. This article aims to fill this gap. As we will see, the health policy on immigrants in Portugal can illuminate not only the contradictions of Portuguese society but also the broader contradictions of the Welfare State in the new global economy.info:eu-repo/semantics/publishedVersio

Clear detection of dusty torus signatures in a Weak-Line Radio Galaxy: the case of PKS 0043-42

We report the clearest detection to date of dusty torus signatures in a Weak-Line Radio Galaxy (WLRG). The deep Spitzer InfraRed Spectrograph (IRS) rest-frame mid-infrared (MIR) spectrum of the WLRG PKS 0043-42 (z=0.116) shows a clear spectral turnover at wavelengths longer than ~20 micron suggestive of warm dust, as well as a 9.7 micron silicate absorption feature. In addition, the hard X-ray results, based on Chandra data, strongly support a picture in which PKS 0043-42 has a torus and accretion disc more typical of Strong-Line Radio Galaxies (SLRGs). The MIR and X-ray spectra are markedly different from those of other WLRGs at similar redshifts, and here we show that the former can be successfully fitted with clumpy torus models with parameters characteristic of Type-2 AGN tori: close to edge-on (i=74 deg) and relatively broad (torus angular width=60 deg), with an outer radius of 2 pc, hydrogen column density ~1.6x10^(23) cm^(-2), and AGN bolometric luminosity ~1.6x10^(44) erg s^(-1). The presence of a compact torus in PKS 0043-42 provides evidence that this WLRG is fuelled by cold, rather than hot, gas accretion. We suggest that WLRGs are a diverse population, and PKS 0043-42 may represent a type of radio galaxy in which the AGN activity has been recently re-triggered as a consequence of intermittent gas supply, or in which the covering factor of the Narrow-Line Region (NLR) clouds is relatively low.Comment: 7 pages, 6 figures, 1 table. Accepted by MNRA

Intragranitic locle golcl cleposits in the Tomiño area (Ponteveclra)

[Resumen] En este trabajo se describen las principales características de las mineralizaciones auríferas filonianas que aparecen en varios cuerpos graníticos sintectónicos en el área de Tomillo (SW de la provincia de Pontevedra), haciendo también referencia al contexto geológico en el que dichas mineralizaciones se presentan. Se trata de venas y filones de cuarzo con sulfuros (pirita, arsenopirita y calcopirita principalmente), con greisenización asociada, originados como consecuencia de un proceso neumatolítico-hidrotermal controlado por el sistema de fracturas de los granitos encajantes. Pueden diferenciarse cinco paragénesis consecutivas: postmagmática, de endogreisen, hidrotermal temprana, hidrotermal tardía y supergénica. El oro se presenta en forma de inclusiones microscópicas dentro de los sulfuros (principalmente en la calcopirita), que van aumentando en tamaño y proporciór a lo largo de las etapas sucesivas del proceso de mineralización.[Abstract] The main characteristics of lode gold deposits ocurring in sorne syntectonic granitic bodies in the Tomiño Area (SW of Pontevedra province) are described in this work. The geological context of this mineralization type is also referred to. The mineralizations consist of quartz-veins bearing sulphides (mainly pyrite, arsenopyrite and chalcopyrite), with associated greisenization in the wallrock, produced by a pneumatolytic-hydrothermal process that is controlled by the fracture system in the host granites. Five consecutive paragenesis can be distinguished: postmagmatic, endogreisen, early hydrothermal, late hydrothermal and supergene. Gold oeeurs as mieroseopie inelusions inside sulphides (mainly in ehalco-pyrite), inereasing in size and proportion along the sueeesive stages in the mineralization proeess