High resolution imaging with Fresnel interferometric arrays: suitability for exoplanet detection

We propose a new kind of interferometric array that yields images of high dynamic range and large field. The numerous individual apertures in this array form a pattern related to a Fresnel zone plate. This array can be used for astrophysical imaging over a broad spectral bandwidth spanning from the U.V. (50 nanometers) to the I.R. (20 microns). Due to the long focal lengths involved, this instrument requires formation-flying of two space borne vessels. We present the concept and study the S/N ratio in different situations, then apply these results to probe the suitability of this concept to detect exoplanets.Comment: 12 pages, 19 figures, to be published in A&

Les prémisses françaises d’un droit international public au milieu du XVIe siècle. La « philosophie civile et d’Estat » de Jean d’Arrérac

El jurista y juez del Parlamento de Burdeos Jean d’Arrérac fue el autor de un tratado sobre la Irenarquía y la polemarquía publicado en 1558. Pertenece a una corriente jurídica y filosófica nueva. Intenta relacionar el antiguo realismo procedente del tomismo con un humanismo que proclama un nuevo “ius humanae societatis”. Más allá de las reglas que deben regir la guerra de la manera más justa posible, plantea, en la línea de Suárez y Vitoria, los límites internos y externos de la soberanía. Estas premisas de un equilibrio entre las sociedades humanas y de una universalidad formal y jurídica participan en la fundación de las bases del derecho público internacional.The jurist and judge of the Parliament of Burgundy Jean d’ Arrérac was the author of a treaty on the Irenarchy and the polemarchy published in 1558. He belongs to a new philosophical and legal current. He tries to relate the old realism issued from the old Tomism with a humanism that proclaims a new “ius humanae societatis”. Beyond the rules that should govern the war in the fairest way it is possible, presents, in the line of Suárez and Vitoria, the external and internal limits of sovereignty. These premises of a balance between the human societies and a legal and formal universality are in the foundation of the bases of the International Public Law

Un grand juriste européen : Saint Benoît de Nursie

El autor, tras recordar los datos biográficos conocidos sobre San Benito, llama la atención sobre la vertiente jurídica de la Regla Benedictina, fijándose para ello en dos aspectos: la comunidad y el poder en el seno de la congregación monástica y, en segundo lugar, el papel del juez y de la justicia (la penalidad) dentro de dicha comunidad.The author, after remembering the biographic data known about Saint Benedict, points out the juridical side of the Benedictine Rule, taking into account, for this purpose, two different aspects: the community and the powerinside the monastical congregation and, secondly, the role of judge and justice (criminality) inside that community

Du palais a l'université: les professores legum bordelais praticiens et docteurs ( XIVéme-XVéme SIÉCLES )

Las relaciones entre la corte de Justicia y la Universidad muestran una presencia precoz de juristas en las Cortes consuetudinarias de Burdeos, desde el siglo Xll. Entre estos juristas figuran los primeros analistas del derecho local. Su trabajo consistió sobre todo en poner de acuerdo el derecho consuetudinario y el derecho romano. Se constatan, desde el siglo xrv, vínculos entre la utilización cada vez más visible del derecho romano (fundamentalmente el penal), las orientaciones de la Corte Superior de Justicia de Aquitania y la voluntad de guiar esta transformación del derecho hacia el nuevo marco pedagógico de la Escuela de Derecho de la Universidad.The connections between the Law Courts and the University show the presence of legal experts in thebordelaise Customs Courts as early as the twelfth century. Among those apperar the first analysts of Local Law. Their work has consisted, above all, in putting agree Custom. Law and Román Law. In the fourteenth century,we can establish links between the Aquitaine Superior Court of Justice, and the will to lead that legal change in a new educational institution the Law School of University.Publicad

L’avocat dans la procédure des anciennes coutumes médiévales bordelaises

The origins and functions of the lawyers who acted in the judicial scope of Bordeaux area during the Low Middle Ages, from the practice conserved in the old «coutumier» law of the zone; the author is focused in its presence and in the obligations picked up in this legislation, as well as in the ample role played by this law, more and more developed during that time

Space-time estimation of a particle system model

13 pagesLet X be a discrete time contact process (CP) on the discrete bidimensional lattice as define by Durett - Levin (1994) . We study estimation of the model based on space-time evolution on a finite subset of sites. For this, we make use of a marginal pseudo-likelihood. The estimator obtained is consistent and asymptoticaly normal for non-vanishing supercritical CP. Numerical studies confirm these results

Saint Vincent de Paul and the Internment of Minors in Seventeenth-Century France

Considered within the context of his time, Vincent de Paul’s philosophy on the correction of minors at Saint-Lazare was humane. Seventeenth-century French attitudes toward poor persons, and minors in particular, are described. The poor were frequently classified as criminals to be locked up or otherwise restricted and made to serve the state’s purposes. Vincent was original because he believed that the behavior of minors could be corrected through education, and that such education would prevent the criminality associated with poverty at the time. His was “a strategy that combined internal discipline with instruction in the faith.” He believed that “innocence could always be recovered.” In this, he was unlike his contemporaries who viewed children as living in an unreasoning state close to that of beasts or the insane. From Vincent’s perspective, internment was less to protect society from minors and more to protect minors from society. The article outlines the different types of minors who were interned at Saint-Lazare and explains what the monastic life imposed on them was supposed to accomplish. Vincent’s work with foundlings is also discussed

Three-dimensional foam flow resolved by fast X-ray tomographic microscopy

Thanks to ultra fast and high resolution X-ray tomography, we managed to capture the evolution of the local structure of the bubble network of a 3D foam flowing around a sphere. As for the 2D foam flow around a circular obstacle, we observed an axisymmetric velocity field with a recirculation zone, and indications of a negative wake downstream the obstacle. The bubble deformations, quantified by a shape tensor, are smaller than in 2D, due to a purely 3D feature: the azimuthal bubble shape variation. Moreover, we were able to detect plastic rearrangements, characterized by the neighbor-swapping of four bubbles. Their spatial structure suggest that rearrangements are triggered when films faces get smaller than a characteristic area.Comment: 5 pages, 5 figure

The Vector Vortex Coronagraph: Laboratory Results and First Light at Palomar Observatory

High-contrast coronagraphy will be needed to image and characterize faint extra-solar planetary systems. Coronagraphy is a rapidly evolving field, and many enhanced alternatives to the classical Lyot coronagraph have been proposed in the past ten years. Here, we discuss the operation of the vector vortex coronagraph, which is one of the most efficient possible coronagraphs. We first present recent laboratory results, and then first light observations at the Palomar observatory. Our near-infrared H-band (centered at ~ 1.65 microns) and K-band (centered at ~ 2.2 microns) vector vortex devices demonstrated excellent contrast results in the lab, down to ~ 1e-6 at an angular separation of 3 lb/d. On sky, we detected a brown dwarf companion 3000 times fainter than its host star (HR 7672) in the Ks band (centered at ~2.15 microns), at an angular separation of ~ 2.5 lb/d. Current and next-generation high-contrast instruments can directly benefit from the demonstrated capabilities of such a vector vortex: simplicity, small inner working angle, high optical throughput (>90%), and maximal off-axis discovery space

Adaptive optics in high-contrast imaging

The development of adaptive optics (AO) played a major role in modern astronomy over the last three decades. By compensating for the atmospheric turbulence, these systems enable to reach the diffraction limit on large telescopes. In this review, we will focus on high contrast applications of adaptive optics, namely, imaging the close vicinity of bright stellar objects and revealing regions otherwise hidden within the turbulent halo of the atmosphere to look for objects with a contrast ratio lower than 10^-4 with respect to the central star. Such high-contrast AO-corrected observations have led to fundamental results in our current understanding of planetary formation and evolution as well as stellar evolution. AO systems equipped three generations of instruments, from the first pioneering experiments in the nineties, to the first wave of instruments on 8m-class telescopes in the years 2000, and finally to the extreme AO systems that have recently started operations. Along with high-contrast techniques, AO enables to reveal the circumstellar environment: massive protoplanetary disks featuring spiral arms, gaps or other asymmetries hinting at on-going planet formation, young giant planets shining in thermal emission, or tenuous debris disks and micron-sized dust leftover from collisions in massive asteroid-belt analogs. After introducing the science case and technical requirements, we will review the architecture of standard and extreme AO systems, before presenting a few selected science highlights obtained with recent AO instruments.Comment: 24 pages, 14 figure