IVOA Recommendation: The UCD1+ controlled vocabulary Version 1.23

This document describes the list of controlled terms used to build the Unified Content Descriptors, Version 1+ (UCD1+). The document describing the UCD1+ can be found at the URL: http://www.ivoa.net/Documents/latest/UCD.html. This document reviews the structure of the UCD1+ and presents the current vocabulary

IVOA Recommendation: IVOA Photometry Data Model

The Photometry Data Model (PhotDM) standard describes photometry filters, photometric systems, magnitude systems, zero points and its interrelation with the other IVOA data models through a simple data model. Particular attention is given necessarily to optical photometry where specifications of magnitude systems and photometric zero points are required to convert photometric measurements into physical flux density units

IVOA Recommendation: Vocabularies in the Virtual Observatory Version 1.19

This document specifies a standard format for vocabularies based on the W3C's Resource Description Framework (RDF) and Simple Knowledge Organization System (SKOS). By adopting a standard and simple format, the IVOA will permit different groups to create and maintain their own specialised vocabularies while letting the rest of the astronomical community access, use, and combine them. The use of current, open standards ensures that VO applications will be able to tap into resources of the growing semantic web. The document provides several examples of useful astronomical vocabularies

Working with Gravitational-Wave sky localizations: new methods and implementations

International audience; The era of multi-messenger astrophysics with Gravitational Waves (GW) requires the exploration and development of suitable methods and tools for real-time analysis as well as post-processing activities. The irregular and complex shapes of the GW sky localizations represent a new challenge for observational astronomers, who need to work with fast tiling, catalog queries, transient localizations, visibility and sky map comparisons. Here we show how gravitational-wave sky maps can be easily and efficiently visualized and processed using Multi-Order Coverage (MOC) maps. These maps are based on HEALPix sky tessellation which uses both Python language and the recent implementation in Aladin Desktop/Lite. In addition to this, we describe a specific interactive script, named GWsky, that we developed to effectively tile the sky localization of a gravitational-wave event providing accurate telescope pointings. We also show applications of these methods and tools for educational purposes in Virtual Reality Apps, high resolution images, and basic sonification of the GW sky maps.Finally, we describe possible evolutions of such implementations when three or more ground-based interferometers will be involved in a gravitational-wave source localization (i.e. Virgo,LIGO–Hanford, LIGO–Livingston, KAGRA, LIGO–India) with a corresponding increase of the sky map resolution

IVOA Recommendation: Spectrum Data Model 1.1

We present a data model describing the structure of spectrophotometric datasets with spectral and temporal coordinates and associated metadata. This data model may be used to represent spectra, time series data, segments of SED (Spectral Energy Distributions) and other spectral or temporal associations.Comment: http://www.ivoa.ne

Gestion de grands catalogues et application de releves infrarouges a l'etude de la structure galactique

The first part of this thesis concerns the management of very large astronomical catalogues. Two large projects aiming at covering the sky at near-infrared wavelength were running during this thesis: DENIS and 2MASS. I present the dedicated lossless compression methods, preserving an indexation based on celestial positions, that have been developed for the point source catalogues of these two surveys. Optimized coding leads to compression factors 1.5 to 2 times better than those achieved by LZ77-type algorithms. The first versions of the DENIS and 2MASS catalogues are fully integrated into the CDS services (VizieR, Aladin), and can be queried via the Web, with average response times below 20 microseconds per source. Within the frame of the DENIS project, data validation has allowed the first public release for this survey (\url(http://cdsweb.u-strasbg.fr/denis-public/)). Comparison of data reduced by the two DENIS pipelines (LDAC and PDAC) led to the definition of filtering criteria for selecting PDAC data suitable for Galactic structure studies. The second part of this thesis is based on the use of a modified version of the Besançon synthetic model of stellar population synthesis. The disc density laws have been changed to allow simulation of a warped and/or flaring stellar disc. Comparisons with PDAC data yield a 2.5~kpc scale length for the thin disc, with radial cutoff at 14~kpc. I present a method for reconstructing the 3D structure of extinction by fitting the model on DENIS data. The warp is observed between $l=230$ and 330\degres\xspace, bending the disc towards $b<0$, as in the gas. The warp is found to start close to the Sun ($R=8.4$~kpc), and the radius for the flare depends on the galactic longitude.La première partie de cette thèse concerne la gestion des très grands catalogues astronomiques. Deux grands projets de cartographie du ciel dans l'infrarouge proche, DENIS et 2MASS, étaient en cours pendant ce travail de thèse. Je présente les méthodes de compression, sans perte d'information et préservant une indexation sur la base des positions célestes, développées pour les catalogues de sources ponctuelles de ces deux relevés. Le codage optimisé permet un gain de compression d'un facteur 1.5 à 2 par rapport à des algorithmes de type LZ77. Les premières versions des catalogues DENIS et 2MASS sont pleinement intégrées aux services du CDS (VizieR, Aladin), et donc interrogeables par le Web, avec des temps d'accès moyens inférieurs à 20 microsecondes par source. Dans le cadre du projet DENIS, le travail de validation des données a permis, dans un premier temps, la première diffusion publique pour ce relevé (\url(http://cdsweb.u-strasbg.fr/denis-public/)). La comparaison des données réduites par les deux chaînes de traitement DENIS (LDAC et PDAC) a ensuite permis de définir des critères de filtrage et d'utiliser les données PDAC pour l'étude de la structure Galactique. La deuxième partie de la thèse s'appuie sur une version modifiée du modèle de synthèse de populations stellaires de Besançon. Les lois de densité du disque ont été modifiées pour pouvoir simuler un disque stellaire gauchi et/ou évasé. Les comparaisons avec les données PDAC indiquent une échelle de longueur $h_R=2.5$~kpc pour le disque, avec une troncature à $R=14$~kpc. Je discute une méthode de reconstruction tridimensionnelle de l'extinction par ajustement du modèle sur les données DENIS. Le gauchissement du disque galactique est observé entre $l=230$ et 330\degres\xspace, et se traduit par une inclinaison du disque stellaire vers $b<0$, comme pour le gaz. Le gauchissement commence près de la position du Soleil ($R=8.4$~kpc), et l'origine de l'évasement montre une dépendance en longitude

VO for Everyone - Getting Ready for the 4th ASTERICS DADI VO School

4 pages, 2 figures, ADASS XXIX proceedingsInternational audienceWe present an update on the efforts of the European Virtual Observatory (EURO-VO) to inform and educate the astronomical community about Virtual Observatory (VO) tools and services. From the 20th to the 22nd of November 2018 the fourth and last Virtual Observatory school of work package 4 (DADI) of the European ASTERICS project has been taking place in Strasbourg. In the light of this event, this paper provides details on the VO-School highlighting the elements of the schools that we consider makes them a success. We present a short overview of recent developments, the current status and content, and future plans for tutorials on the Virtual Observatory

Interactive Submission of Data to be Published in VizieR

International audienceWe present the new interactive submission interface for VizieR and the VizieR associated data service (Landais (2016)). The step by step process supports description of tables and the generation of the CDS standard ReadMe description. This interface also guides authors through a workflow that allows them to describe their data in a standard way so that it can be integrated into the VizieR database (Ochsenbein et al. (2000)) and be published via Virtual Observatory protocols. The VizieR associated data service is a recent addition to the CDS VizieR service. It enables the publication of data associated to papers, such as spectra, images and time series. The interface automatically proposes a mapping of the FITS headers to the IVOA ObsCore meta-data standard (Tody et al. (2011)), which can be modified and validated by the authors. The process can be done in an asynchronous mode and is therefore suited to potentially large collections of FITS resources, and is instantaneous for small data sets.The associated data service today comprises of millions of associated data files. We describe the capabilities of the submission interface, and the lessons learned from initial tests by authors/beta-testers