The SIMBAD astronomical database

Simbad is the reference database for identification and bibliography of astronomical objects. It contains identifications, `basic data', bibliography, and selected observational measurements for several million astronomical objects. Simbad is developed and maintained by CDS, Strasbourg. Building the database contents is achieved with the help of several contributing institutes. Scanning the bibliography is the result of the collaboration of CDS with bibliographers in Observatoire de Paris (DASGAL), Institut d'Astrophysique de Paris, and Observatoire de Bordeaux. When selecting catalogues and tables for inclusion, priority is given to optimal multi-wavelength coverage of the database, and to support of research developments linked to large projects. In parallel, the systematic scanning of the bibliography reflects the diversity and general trends of astronomical research. A WWW interface to Simbad is available at: http://simbad.u-strasbg.fr/SimbadComment: 14 pages, 5 Postscript figures; to be published in A&A

Multivariate Data Analysis Applied to Bibliographical Information Retrieval: SIMBAD Quality-Control

this paper, we describe the second method. Preprint submitted to Elsevier Science 5 July 2 Parametrization of the Bibliographical Information 2.1 Method The articles in major astronomical journals are an important source of useful information to check the coherence of the SIMBAD data. We wanted to show that the bibliographical reference information concerning one object is quantifiable and can be compared to other information in the database to detect anomalies. One of the possibilities to analyse the content of a document is to use multivariate data analysis. Factor-space (Ossorio, 1965) is an n-dimensional relevancy space. This space is described by n axes representing a set of n subject matter headings. The words and phrases can be used to scale the axes, and documents are then a vector average of the terms within them. These relevancy scores may be obtained either directly, using human judgement (Ossorio, 1965) or via automated evaluation of classified collections of documents using statistical analysis (Kurtz, 1992). Presently, we simplify our Factor-space by using keywords instead of subject matter headings (Lesteven, 1994). Our research is presently based on SIMBAD and on the NASA-STI bibliographic database. In the NASA-STI database, references are described by the title, the authors, the journal, a list of keywords, the publication year, an abstract and other information. For each category of SIMBAD data (object type, spectral type, IRAS flux, : : :) we can build a specialized "bibliographical space" where the variables are the keywords associated with the selected references and the individuals are the different values of the checked data. To extract the information, we used a Principal Component Analysis (PCA). PCA is the simplest of the multivariate methods..

Identifying the Important Papers for One Astronomical Object

International audienceIn astronomical databases, such as SIMBAD, the number of bibliographical references attached to one astronomical object is continuously growing with the accumulation of published literature over the years. Some objects are cited in many papers, and it may be difficult to identify the most relevant papers, i.e. those which contain extensive results about that object. A first aid for the evaluation of the relevance of a paper consists in reporting additional information about the importance of the object in the article. The number of citations of the object in the paper gives one measure. The relevance can also be evaluated from the location of the citations of the object name in the paper. As an example, when the object name appears in the title of the paper or/and as an "Individual" keyword, that object is generally extensively studied. The variable nomenclature used to designate the astronomical objects is one of the obstacles to be taken into account to derive a significant measure of the impact of the various papers dealing with one object. An evaluation of the classification criteria will be presented

A spatial user interface to the astronomical literature

International audienceWe recall the properties of the Kohonen self-organizing feature map (SOM or SOFM), and explain how such maps can be used for information retrieval. We present an application to a bibliographic database. Our neural net can contain more than one level when necessary, which allows users to modify its spatial configuration. It is available for interactive use on the World-Wide Web (http://simbad.u-strasbg.fr/A+A/map.pl). The interface that we have designed for browsing in the documentary database will be explained in detail

Visual Exploration of Astronomical Documents

International audienceThe CDS bibliographical map is a tool for organizing astronomical text documents into a meaningful map for exploration and search. The system is based on the Self Organizing Map (SOM) algorithm that automatically organizes documents into a two-dimensional grid so that related documents appear close to each other and general topics appear in well defined area. After the determination of optimal parameters for the SOM's learning process, we have developed a graphical WWW interface which allows the visualization of the document distribution. It shows the localization of documents related to given topics (keyword queries). The map is clickable and provide links to the documents. Recent developments include detailed map of small areas, full text indexing, automatic labeling, ... Some applications will be presented. One map is available for interactive use on the Web (http://simbad.u-strasbg.fr/A+A/map.pl)

Maps of information spaces: Assessments from astronomy

International audienceWe discuss the implementation of a cartographic user interface to bibliographic and other information subspaces in astronomy. This includes a front end to two of the five premier scholarly journals in astronomy. We present a range of comparative assessments, in operational frameworks, of this approach to accessing and retrieving astronomical information. Finally, we discuss the particular role that such cartographic user interfaces can play in Web-based information seeking, and contrast this with widely used currently available search technologies

Shared nomenclature and identifiers for telescopes and instruments

International audienceIn the context of sharing public data, science results are expected to be reproducible and therefore we need full traceability of the origin of the data. On the documentalist side, there is a need to relate instrumental origins to the published data. We propose to define a shared nomenclature to index each publication with unique designations for facilities, telescopes and instruments which could benefit from the Virtual Observatory work on semantics. This would help the documentalists to check the consistency of the instrument description in publications or make it more explicit. Observation period, data quality and spectral coverage, for instance, may be checked by referencing a global instrumentation service which gathers the nominal observation parameters for the telescope/facility/instrument involved. Based on this indexation mechanism, then the bibliographic metrics for telescope /instrument usage would be easy to compute, and tracking services like the ESO telescope bibliography database (TelBib) or others would be easier to feed. This paper traces the existing initiatives and gives the example of a facility description framework reusing Virtual Observatory metadata which could be fed by the community

Bibliographical references : from publishers to SIMBAD

<p>Poster that represent different steps of bibliographical data processing for the Simbad database.</p

Integrating Astronomical Data and Information Services at the CDS

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. 1 Introduction The objective of the Strasbourg astronomical Data Centre (CDS) is to provide on-line data and information for the world-wide astronomy community in a multi-wavelength and multi-mission approach. In the present context, with an unprecedented accumulation of data being collected by ground- or space-based telescopes and observatories, the role of the data centres is to bridge the gap between the specialized approach of the scientific teams (where the detailed expertise about the specific data resides), and the general approach of the wider community of researchers (who need an easy access to data, calibrated as far as po..

What is in SIMBAD?

International audienceSIMBAD is a dynamic database of astronomical objects. It provides the bibliography, as well as basic information such as the nature of each object, its coordinates, magnitudes, proper motions and parallax, velocity/redshift, angular size, spectral or morphological type, and the multitude of names (identifiers) given in the literature. The information in SIMBAD is a compilation built from what is published in the literature with expert cross-identification performed at the CDS based on the compatibility of several parameters, to the limit of reasonably good astrometry. We show the data integration processes in SIMBAD