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Divisions >> Department of physics of stellar systems >> Centre for Astronomical Data

Centre for Astronomical Data

Head of the group

Dr. Dluzhnevskaya Olga B.

MAIN FIELDS OF RESEARCH

 


Development of the methods of parametrization of the stars; investigation of the stellar extinction in the Milky Way.

We study possibilities to parameterize stars and interstellar medium from multicolor photometry performed in modern photometric surveys (GALEX, SDSS, 2MASS, WBVR, etc.). For this purpose, we have developed a method to estimate stellar radius from effective temperature and gravity with the help of evolutionary tracks and model stellar atmospheres. In accordance with the evolution rate at every point of the evolutionary track, star formation rate, and initial mass function, a weight is assigned to the resulting value of radius that allows us to estimate the radius more accurately.

Detection of a composite flux in photometry can also serve as an indication of a photometrically unresolved binarity and can contribute to the parameterization of the components of binary systems. We have developed a method of automatic photometric detection of binaries, based on multi-color photometry, theoretical stellar spectral energy distributions and general understanding of binary evolution. When one considers an ultraviolet photometry, then, in combination with optical and infrared photometry, interstellar reddening can be easier distinguished from temperature reddening. Usage of an interstellar extinction law gives us theoretical color-indices of reddened objects, both single stars and unresolved binaries. When plotted on a multidimensional color space, they allow us to indicate areas, where unresolved binaries can be easily separated from single stars, and to identify binaries among objects, cross-matched in photometric surveys.

Investigators:
O.Yu. Malkov, S.G. Sichevskij, E.Yu. Kilpio, D.A. Chulkov, in collaboration with A.V. Mironov (Sternberg Astronomical Institute of the Moscow State University).

Main publications:

 

Studies of binary and multiple stars. Creation, development, support and management of the astronomical catalogues and databases.

Scientific results strongly rely on previous studies, experiments, and observations. A large number of catalogues is produced by astronomers and needs to be available to the whole community. To support astronomers in their daily research work, we collect, verify, homogenize, and organize catalogued information on binary and multiple stars in the most appropriate and comprehensible way.

Catalogues were selected for integration with priority given to those which can help provide an optimal support for the large projects conducted within the astronomical community. A large effort was devoted in recent years to catalogues of binary stars of various observational types: common proper motion, interferometric, spectroscopic binaries, etc. However, due to lack of comprehensive data sources, in many cases we have constructed general lists of binaries of some specific observational type, e.g., for visual, orbital, eclipsing and X-ray binaries.

Various catalogues mentioned above serve as data sources for binary stars of different observational types. However, there was no database synthesizing the various categories, and the Binary and multiple stars DataBase (BDB, bdb.inasan.ru), developed in Institute of Astronomy, aims to fill this gap.

The BDB database presently contains data on physical and positional parameters for about 260,000 components of 120,000 stellar systems of multiplicity 2 to more than 20, taken from a large variety of published catalogues and databases. To designate and cross-identify components and systems correctly, a self-consistent identification scheme for objects in binary and multiple stars, BSDB, was developed. Also, the Identification List of Binaries (ILB) was constructed to facilitate cross-referencing between different catalogues of binary stars.
BDB is developing both in size, including new catalogues, and in depth, adding new features improving usability and promoting integration of the Virtual Observatory standards. BDB can serve as a database for deriving and combination of empirical data for all types of binary/multiple systems, for determination of stellar and orbital parameters and construction of fundamental relations between them throughout the entire stellar mass and orbital separation ranges, for study of star formation history of binary and single stars and for the preparation of future observing programs concerning various types of binaries.

Investigators:
O.Yu. Malkov, P.V. Kaygorodov, D.A. Kovaleva, D.A. Chulkov, L.R. Yungelson, in collaboration with E.A. Avvakumova (Ural Federal University), B. Debray (Institut UTINAM, , Observatoire des Sciences de l'Univers THETA de Franche-Comté Bourgogne, Université de Franche-Comté, France), V. Tamasian and J. Docobo (Observatorio Astronómico Ramón María Aller, Universidade de Santiago de Compostela, Spain).

Main publications:

 

Development of the Russian Virtual Observatory and its integration into the International Virtual Observatory.

Virtual Observatory is a collection of integrated astronomical data archives and software tools that utilize computer networks to create an environment in which research can be conducted. About fifteen years ago several countries initiated national virtual observatory programs that combine existing databases from ground-based and orbiting observatories and make them easily accessible to researchers. As a result, data from all the world's major observatories will be available to all users and to the public. This is significant not only because of the immense volume of astronomical data but also because the data on stars and galaxies have been compiled from observations in a variety of wavelengths: optical, radio, infrared, gamma ray, X-ray and more. Each wavelength can provide different information about a celestial event or object, but also requires a special expertise to interpret. In a virtual observatory environment, all of this data is integrated so that it can be synthesized and used in a given study.

The International Virtual Observatory Alliance (IVOA) represents twenty national and international projects working in coordination to realize the essential technologies and interoperability standards necessary to create a new research infrastructure. Russian Virtual Observatory (RVO) is one of the founders and important members of the IVOA. Principal RVO goals are stated as follows: i) to provide Russian astronomical community with a convenient access to the world astronomical resources and ii) to unite Russian data, to provide them to the rest of the world and to integrate them into the International Virtual Observatory.

For this purpose, the RVO issues regular reviews of Russian astronomical data sources. Their aim is to analyze main directions of creation and functioning of major data sources constructed by Russian astronomers or with their participation and to compare them with the worldwide trends in these fields. In particular, archives of space projects should be mentioned: past (Astron), present (INTEGRAL, Radioastron), future (SRG, WSO-UV) and planned (Lyra-B, Svecha) missions. High quality photometric (WBVR catalogue) and spectroscopic (VALD database) data sources should be mentioned. Russian contribution to the collection, analysis and dissemination of astronomical data on minor bodies of the Solar System, on variable stars, and on binary and multiple stars of all observational types is also extremely valuable.

An ultimate goal of Virtual Observatory is to strengthen scientific applications of world astronomical data. One of direct applications for the Virtual Observatory community is that of merging catalogues and surveys in order to generate customized views of data. Developing methods for analyzing and extracting information from modern sky surveys is a challenging task in astrophysical studies

Investigators:
O.B.Dluzhnevskaya, O.Yu.Malkov, D.A.Kovaleva, N.N.Samus, S.V.Vereschagin, in collaboration with L.A.Kalinichenko, N.A.Skvortsov, S.A.Stupnikov (IPI RAS), I.V.Zolotukhin (Sternberg Astronomical Institute of the Moscow State University), A.S.Pozanenko (IKI RAS).

Main publications:


 Astronomical data management

CAD-provided resources

Regularly updated resources

 

Selected VizieR catalogues authored by CAD staff:


Mirrors of major databases


Tutorials and information on how to use and manage resources of astronomical data (in Russian)

 

Tutorials on Astronomical data tools and sources management


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