Francoise Genova

The Aladin Interactive Sky Atlas

The subject of this symposium, Multi-Wavelength Sky Surveys naturally invokes a discussion of methods of astronomical object identification and classification: Given a set of objects detected at a certain waveband, how does one integrate the new sources with previous data? The ALADIN system (Paillou et al. 1994) of the CDS is a software package designed to tackle this problem: It provides simultaneous access to digitized sky photographs, catalogs and databases to facilitate direct, visual comparison of user data with previously classified data, as well as automatic source extraction and calibration tools.

The SPECFIND V2.0 catalogue of radio cross-identifications and spectra - SPECFIND meets the Virtual Observatory

The new release of the SPECFIND radio cross-identification catalogue, SPECFIND V2.0, is presented. It contains 107488 cross-identified objects with at least three radio sources observed at three independent frequencies. Compared to the previous release the number of entry radio catalogues is increased from 20 to 97 containing 115 tables. This large increase was only made possible by the development of four tools at CDS which use the standards and infrastructure of the Virtual Observatory (VO). This was done in the framework of the VO-TECH European Design Study of the Sixth Framework Program. We give an overview of the different classes of radio sources that a user can encounter. Due to the increase of frequency coverage of the input radio catalogues, this release demonstrates that the SPECFIND algorithm is able to detect spectral breaks around a frequency of ~1 GHz.

A method for determining radio continuum spectra and its application to large surveys

A new tool to extract cross-identifications and radio continuum spectra from radio catalogues contained in the VIZIER database of the CDS is presented. The code can handle radio surveys at different frequencies with different resolutions. It has been applied to 22 survey catalogues at 11 different frequencies containing a total of 3.5 million sources, which resulted in over 700 000 independent radio cross-identifications and ∼67 000 independent radio spectra with more than two frequency points. A validation of the code has been performed using independent radio cross-correlations from the literature. The mean error of the determined spectral index is ±0.3. The code produces an output of variable format that can easily be adapted to the purpose of the user.

The International Virtual Observatory Alliance: recent technical developments and the road ahead

The International Virtual Observatory Alliance (IVOA: http://www.ivoa.net) represents 14 international projects working in coordination to realize the essential technologies and interoperability standards necessary to create a new research infrastructure for 21st century astronomy. This international Virtual Observatory will allow astronomers to interrogate multiple data centres in a seamless and transparent way, will provide new powerful analysis and visualisation tools within that system, and will give data centres a standard framework for publishing and delivering services using their data. The first step for the IVOA projects is to develop the standardised framework that will allow such creative diversity. Since its inception in June 2002, the IVOA has already fostered the creation of a new international and widely accepted, astronomical data format (VOTable) and has set up technical working groups devoted to defining essential standards for service registries, content description, data access, data models and query languages following developments in the grid community. These new standards and technologies are being used to build science prototypes, demonstrations, and applications, many of which have been shown in international meetings in the past two years. This paper reviews the current status of IVOA projects, the priority areas for technical development, the science prototypes and planned developments.

Luminous AGB stars in nearby galaxies A study using Virtual Observatory tools

Aims. This study focuses on very luminous (Mbol 1.5 mag and H − Ks > 0.4 mag in the LMC, SMC, M 31, and M 33 from 2MASS data. Methods. The data were taken from the 2MASS All-Sky Point Source catalogue archive. We used Virtual Observatory tools and took advantage of its capabilities at various stages in the analysis. Results. It is well known that stars with the colors we selected correspond mainly to carbon stars. Although the most luminous AGBs detected here contain a large number of carbon stars, they are not included in existing catalogues produced from data in the optical domain, where they are not visible since they are dust-enshrouded. A comparison of the AGB stars detected with combined near and mid–infrared data from MSX and 2MASS in the LMC shows that 10% of the bright AGB stars are bright carbon stars never detected before and that the other 50% are OH/IR oxygen rich stars, whereas the 40% that remain were not cross–matched. Conclusions. The catalogues of the most luminous AGB stars compiled here are an important complement to existing data. In the LMC, these bright AGB stars are centrally located, whereas they are concentrated in an active star-formation ring in M 31. In the SMC and M 33, there are not enough of them to draw definite conclusions, although they tend to be centrally located. Their luminosity functions are similar for the four galaxies we studied.

The precision of large radio continuum source catalogues - An application of the SPECFIND tool

The accuracy in position and flux density of 19 large radio continuum source catalogues has been determined using SPECFIND, a new tool recently made available through the CDS. The ∼67 000 radio continuum spectra with three or more frequencies produced by SPECFIND were used to cross-correlate sources from different catalogues and to calculate offsets in right ascension and declination in the various catalogues with respect to the positions given in the NRAO VLA Sky Survey (NVSS) catalogue, which was adopted as a reference. The flux densities reported in the catalogues were compared to those predicted by the composite spectra, enabling us to assess the quality of the flux density calibration of the different catalogues.

Integrating astronomical data and information services at the CDS

Abstract The CDS is providing several unique services to the world-wide astronomical community: the catalogue service, the SIMBAD database, the ALADIN project, bibliography and literature search, yellow pages, etc. We describe how the CDS works at providing a global perspective on astronomical data and information, with the help of recent technological developments.

CDS as an astronomical information HUB

Absract The Centre de Donnees astronomiques de Strasbough (CDS) has undergone significant evolution in recent years, with the development of new services and a new interfaces, and an extension of its activities linked to the growth in the amount and diversity of data produced in astronomy. The CDS objectives, and the present status of the services, will be recalled. The main evolution trends observed on the medium term, due to the evolution of astronomy and to the very fast technical evolution, will be described. Finally, the strong growth of interconnection between astronomy on-line services, including electronic journals, will be discussed.

DIVISION XII / COMMISSION 5 / WORKING GROUP DESIGNATIONS

At the 2003 Sydney IAU meeting, Marion Schmitz (Caltech, USA) took over the chair of the Commission 5 Working Group Designations, succeeding Helene Dickel. The Working Group Designations of IAU Commission 5 clarifies existing astronomical nomenclature and helps astronomers avoid potential problems when designating their sources. The most important function of WG Designations during the period 2003-2005 was overseeing the IAU REGISTRY FOR ACRONYMS (for newly discovered astronomical sources of radiation: see the website http://cdsweb.u-strasbg.fr/cgi-bin/DicForm >) which is sponsored by the WG and operated by the Centre de Donnees de Strasbourg (CDS). The Clearing House, a subgroup of the WG, screens the submissions for accuracy and conformity to the IAU Recommendations for Nomenclature ( http://cdsweb.u-strasbg.fr/iau-spec.html >). From its beginning in 1997 through August 2006, there have been 132 submissions and 111 acceptances. Attempts to register asterisms, common star names, and suspected variable stars were rejected. The past three years saw 61 acronyms submitted with 50 of them being accepted. (GIRL - yes; WOMEN - no).

Interoperability tools for the Virtual Observatory

Interoperability is one of the important issues in the current efforts to build the Virtual Observatory. We present here some of the tools which already contribute to the efficient exchange of information between archives and databases.