Virtual Atomic and Molecular Data Centre

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Virtual Atomic and Molecular Data Centre (VAMDC), http://www.vamdc.eu (.org)

As an official project VAMDC started in July 2009, with substantial EU e-Infrastructure Program Project funding for a period of 42 months. There are 15 legal partners encompassing 21 institutes or departments from 6 EU countries, the Russian Federation, Venezuela and Serbia, and there are 2 external partners (NIST and CFA, Harvard). The project may live beyond the 42 months as a laboratory without walls.

The Challenge for VAMDC is to provide data access to all A+M data to all end user communities. The data underpins many areas of research, not limited to plasma- and astrophysics, and the potential users come from industry as well as academia. The data is complex and increasingly large, and the handling of the data often involves the use of application tools. There are issues with ensuring data completeness and quality. With all that in mind the key VAMDC objectives are: (1) to implement a VAMDC interface for accessing major existing databases containing heterogeneous data and aimed at different users; (2) to enable data queries across multiple databases each focused on specific research topics; (3) to facilitate the data publishing and quality control process for major A+M data producers; and (4) to involve wide user and producer communities in the development and use of VAMDC tools. The key end user communities are from astrophysical, atmospheric, plasma and combustion science and from the industrial applications field. They perform simulations, observations, and diagnostic interpretation. There is also a teaching outreach component to VAMDC.

In the VAMDC infrastructure it is foreseen that the user accesses a database through some application that is also part of VAMDC. The application connects with the relevant databases and code services and communication takes place according to standardized formats agreed by VAMDC. In the VAMDC project there are networking activities (training and workshops; connections to other groups), service activities (deployment of A+M database and code services, support to the service and user communities) and research activities (standards development, e.g. XML Schema, dictionaries, a query language, a registry; and publishing and data mining tools).

SLAP (http://www.ivoa.net/Documents/SLAP) defines a protocol for retrieving spectral lines from different spectral line databases through a uniform interface. The interface is meant to be reasonably simple to implement by service providers. A basic query will be done in a wavelength range for the different services. The service returns a list of spectral lines formatted as a VOTable. SSLDM (http://www.ivoa.net/Documents/SSLDM/) is integrated with SLAP to allow seamless access to spectral line transitions available worldwide. In SSLDM objects and attributes are defined to characterize properties of lines that are important in astrophysical contexts. SLAP and SSLDM could be a model for further more complicated applications to collisional data and then possibly molecules and surfaces.

For collisional data the Basecol database (http://basecol.obspm.fr) is an important target for XSAMS or for alternative access protocols. Basecol contains published excitation and de-excitation rate coefficients and level data, presently for 21 target molecules and for perturbers H, He, H2 and e-. Basecol embodies a carefully annotated bibliographic database, calculated collisional rates, graphical visualization of collisional rates, fitted and analytic functions of the collisional rates and the associated coefficients, information on the methods used in the calculation of cross sections and rate coefficients, and energy levels of the molecules taken from spectroscopic databases or theoretical calculations. The rate coefficients tables are linked to tables containing the correspondence between labelling of states and their quantum numbers and energy levels. They are also linked to tables containing the corresponding fitted coefficients as well as the fitted functions.

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