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Ivan Zolotukhin

Publications and source records attributed to Ivan Zolotukhin.

24 records · Page 2Linked to original sources

Middleware for Data Visualization in VO-enabled Data Archives

We present a middleware for visualization and exploration of complex datasets in a VO framework, that performs interaction between data archives and existing VO client applications using PLASTIC. It comprises: (1) PLASTIC-enabled Java control applet, integrated into archive web-pages and interacting with VO applications; (2) cross-browser compatible JavaScript part managing PLASTIC-aware VO Clients (launch, data manipulation) by means of Java LiveConnect. This (or similar) solution is an essential for the new generation VO-enabled data archives providing access to complex observational and theoretical datasets (3D-spectroscopy, N-body simulations, etc.) through web-interface. Thanks to PLASTIC capabilities it is possible to start all necessary client software with a single-click in the archive query result page in a web-browser. This simplifies the scientific usage of the VO resources and makes it easy even for users with no experience in the VO technologies.

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ASPID-SR: Prototype of a VO-compliant Science-Ready Data Archive

ASPID stands for the "Archive of Spectral, Photometric, and Interferometric Data". The world largest collection of raw 3D spectroscopic observations of galactic and extragalactic sources is provided. ASPID-SR is a prototype of an archive of heterogeneous science ready data, fed by ASPID, where we try to exploit all the power of the IVOA Characterisation Data Model. Multi-level Characterisation metadata is provided for every dataset. The archive provides powerful metadata query mechanism with access to every data model element, vital for the efficient scientific usage of a complex informational system. We provide a set of access interfaces: SIAP/SSAP, HTTP-based characterisation metadata query, Web-service accepting ADQL/x.

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Comprehensive Metadata Query Interface for Heterogeneous Data Archives Based on Open Source PostgreSQL ORDBMS

We use PostgreSQL DBMS for storing XML metadata, described by the IVOA Characterisation Data Model. Initial XML type support in the PostgreSQL has recently been implemented. We make heavy use of this feature in order to provide comprehensive search over Characterisation metadata tree. We built a prototype of the Characterisation metadata query service, implementing two access methods: (1) HTTP-GET/POST based interface implements almost direct translation of the query parameter name into XPath of the data model element in the XML serialisation; (2) Web-Service based interface to receive XQuery which is also directly translated into XPath. This service will be used in the ASPID-SR archive, containing science-ready data obtained with the Russian 6-m telescope.

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3D Spectroscopy in the Virtual Observatory: Current Status

Three cornerstones for the 3D data support in the Virtual Observatory are: (1) data model to describe them, (2) data access services providing access to fully-reduced datasets, and (3) client applications which can deal with 3D data. Presently all these components became available in the VO. We demonstrate an application of the IVOA Characterisation data model to description of IFU and Fabry-Perot datasets. Two services providing SSA-like access to 3D-spectral data and Characterisation metadata have been implemented by us: ASPID-SR at SAO RAS for accessing IFU and Fabry-Perot data from the Russian 6-m telescope, and the Giraffe Archive at the VO Paris portal for the VLT FLAMES-Giraffe datasets. We have implemented VO Paris Euro3D Client, handling Euro3D FITS format, that interacts with CDS Aladin and ESA VOSpec using PLASTIC to display spatial and spectral cutouts of 3D datasets. Though the prototype we are presenting is yet rather simple, it demonstrates how 3D spectroscopic data can be fully integrated into the VO infrastructure.

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Search for New Open Clusters in Huge Catalogues

Current catalogues of open clusters are rather heterogeneous and incomplete lists of clusters than true catalogues. Before there has been no attempts of automatic search for open clusters in huge photometric catalogues using homogeneous all-sky approach. We have developed such a method based on extraction from catalogue and successive analysis of stellar densities using the colour-magnitude diagrams. Our algorithm finds density peaks and then verifies the significance of these peaks exploiting the fact that in real clusters only stars lying on the isochrone must show density peaks, in contrast with stars lying far from the isochrone on the CMD. In addition such procedure allows to determine the physical parameters: age, distance and color excess of open clusters. Preliminary study of 150 sq. degrees in Galaxy anticenter region yielded several dozens of new clusters. The software developed will allow to build first homogeneous all-sky open cluster catalogue (it will include essentially refined data for known clusters as well) based on 2MASS data.

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