INAF - Osservatorio Astronomico di Trieste

Miscellaneous Information

Miscellaneous Information

Abstract Reference: 30793
Identifier: P4.4
Presentation: Poster presentation
Key Theme: 4 Long-term Management of Data Archives

Common access to 2-D and 3-D galactic radio surveys within the VIALACTEA project

Butora Robert, Molinaro Marco, Smareglia Riccardo

VIALACTEA is a project to facilitate the study of star formation in our Galaxy. It is based on data collected in various galactic surveys from past years. This survey data is available in form of FITS files which are accessed through a web service developed by IA2 (Italian center for Astronomical Archives) at INAF-OATs. The service handles ~30000 3-D radio cubes and 2-D images, originating from about 20 surveys, each offering data on several molecular emission lines. All the data is accessible from one interface in form of a web service. The service offers common functionalities: a search engine to perform data discovery, a cutout engine to create sub-cubes or sub-images and a merge service to unite FITS-files data of adjacent areas on the sky if stored in separate files. This allows one compact 3-D or 2-D data package to be acquired and it would contain only the
sky-spectral area which the astronomer is interested in. The services are uniformly parametrized by sky- and spectral-coordinates independently of data calibration and data subdivision in the original survey FITS-files. Currently supported sky-coordinates are Galactic and ICRS. Spectral axis is given by velocity relative to the observer. The searches are performed against all database or can be narrowed down by survey name, species and transition. Positional search allow for cone and boxed regions. Overlap flags are returned to help the user rank the results. Since some of the functions - specifically merging more FITS-file data - are very CPU intensive, internally the service functions can be distributed through several computing resources. This allows to configure the system for optimal performance.