Estructura de las Burbujas en la región Sureste de la Nube Mayor de Magallanes

Resumen: En este trabajo se presentan resultados preliminares obtenidos a partir del análisis efectuado a la estructura de burbujas de medianas dimensiones situadas en la región Sureste de la Nube Mayor de Magallanes. Mediante el balance de energía determinamos los parámetros característicos de estas estructuras (brillo superficial, densidad electrónica, medida de emisión, masa, Luminosidad, densidad ambiente, edad), lo que nos permitirá discernir cúal es el origen (viento estelar, explosión de supernova o algún otro mecanismo) de las diferentes burbujas que componen el supercascarón LMC 9, para de esta manera tratar de dilucidar si los objetos analizados poseen cinemáticamente alguna identidad de conjunto, o si se trata de objetos relativamente aislados sobre el fondo general difuso al que pertenecen.Abstract: In this work we present preliminary results obtained from the analysis carried on the structure of middle dimensions bubbles located in the southeast region of the Large Magellanic Cloud. We determine by means of the energy balance the characteristics parameters of this structures (superficial brightness, electronic density, emission measure, mass, luminosity, ambiente density, age) which will allow us to discriminate which is the origin (stellar wind, supernova explosion, or other mechanism) of the differents bubbles that form the supershell LMC 9. So, in this way try to elucidate if the analyzed objects have kinematically some identity as group, or if they are objects relatively aisolated against the diffuse background to which they belongFil: Oddone, Mónica. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina.Otras Ciencias Naturales y Exacta

Technology challenges for space interferometry: the option of mid-infrared integrated optics

Nulling interferometry is a technique providing high angular resolution which is the core of the space missions Darwin and the Terrestrail Planet Finder. The first objective is to reach a deep degree of starlight cancelation in the range 6 -- 20 microns, in order to observe and to characterize the signal from an Earth-like planet. Among the numerous technological challenges involved in these missions, the question of the beam combination and wavefront filtering has an important place. A single-mode integrated optics (IO) beam combiner could support both the functions of filtering and the interferometric combination, simplifying the instrumental design. Such a perspective has been explored in this work within the project Integrated Optics for Darwin (IODA), which aims at developing a first IO combiner in the mid-infrared. The solutions reviewed here to manufacture the combiner are based on infrared dielectric materials on one side, and on metallic conductive waveguides on the other side. With this work, additional inputs are offered to pursue the investigation on mid-infrared photonics devices.Comment: Accepted in Adv. in Space Researc

Dynamics of nonequilibrium quasiparticles in a double superconducting tunnel junction detector

We study a class of superconductive radiation detectors in which the absorption of energy occurs in a long superconductive strip while the redout stage is provided by superconductive tunnel junctions positioned at the two ends of the strip. Such a device is capable both of imaging and energy resolution. In the established current scheme, well studied from the theoretical and experimental point of view, a fundamental ingredient is considered the presence of traps, or regions adjacent to the junctions made of a superconducting material of lower gap. We reconsider the problem by investigating the dynamics of the radiation induced excess quasiparticles in a simpler device, i.e. one without traps. The nonequilibrium excess quasiparticles can be seen to obey a diffusion equation whose coefficients are discontinuous functions of the position. Based on the analytical solution to this equation, we follow the dynamics of the quasiparticles in the device, predict the signal formation of the detector and discuss the potentiality offered by this configuration.Comment: 16 pages, 5 figures Submitted to Superconducting Science and Technolog

Exercise #1 Modeling an astrophysical source in preparation for interferometric observations

The following exercices are aimed to get trained to the link between the object intensity distribution and the corresponding visibility curves. They were intended to be the practical application of the seminar "Introduction to visibility modeling" (Berger same volume). This practical session was initially meant to be done with the ASPRO software (see Duvert same volume), uv tables and the fits file can be donwloaded from the ASPRO website. However, any image processing or mathematical software (Idl, Yorick, Mathlab, Mathematica...) associated with the object equations given in Berger can be used for most exercises

Calibration and data reduction of a Stationary Waves Integrated Fourier Transform Spectrometer (SWIFTS)

International audienc

A deep H<i>α</i> survey of the Carina tangent arm direction

International audienceAims. The arm tangent direction provides a unique viewing geometry, with a long path in relatively narrow velocity ranges and lines of view that cross the arm perpendicular to its thickness. The spiral arm tangent regions are therefore the best directions for studying the interstellar medium within spiral density waves in the Milky Way, probing the internal structure in the arms. We focus here on the gas kinematics and star formation in the Galactic plane zone with longitudes of between 281 • and 285.5 • and latitudes of between ∼-2.5 • and ∼1 • , respectively, which contains the Carina arm tangency. Methods. The Carina arm tangent direction was observed as part of a velocity-resolved Hα survey of the southern Milky Way using a scanning Fabry-Perot mounted on a telescope, which makes it possible to obtain data cubes containing kinematic information. Our detailed analysis of the resultant Hα profiles reveals the presence of several layers of ionized gas with different velocities over the surveyed region. We combine the Hα data with multi-wavelength information in order to assign velocity and distance to the H ii regions in the probed area and to study the star-formation activity in the Carina arm tangency. Results. We find that the Carina arm tangency is at l = 282 • , and that it spreads from 2 to 6 kpc with a V LSR range of between-20 and +20 km s-1. We deduce an arm width of ∼236 pc. We also probe the star formation on a scale of ∼1 kpc-2 , showing that the star-formation activity is intermediate in comparison with the quiescient Solar neighborhood and the most active Galactic central molecular zone. From our analysis of the stellar motions extracted from the Gaia DR3 catalog, we observe that stars around 2.5 kpc are tracing the trailing and the leading sides of the arm, while stars at greater distances more closely trace the inner part of the arm. In parallel, we studied the Hα velocity structure of the H ii regions RCW48 and RCW49 in detail, confirming the expansion velocity of ∼20 km s-1 for RCW 49 and the double-shell structure of RCW 48, which is in agreement with a wind interaction with a previous mass-loss episode

Réalisation d'un spectromètre de Fourier statique compact LLIFTS en optique intégrée sur verre

International audienc

Compact spectrometer modelling based on wavelength stationary wave Fourier transform in integrated optics

International audienc

The supergiant interstellar bubble LMC 1

The study of one of the nine objects classified by Meaburn in 1980 as "Supergiant Bubbles" of the Large Magellanic Cloud has been undertaken by using Hα observations carried out with an imaging Fabry-Pérot interference spectrometer. A morphological, kinematical and photometrical study about this object is here presented, supporting the idea that we are dealing with a spheroidal, expanding shell. The probable origin of this huge superstructure is discussed on the basis of energetic considerations for classic stellar-wind and supernova-explosion models. An alternative approach is also discussed.Asociación Argentina de Astronomí