Other activities

People involved at OAB: de Ruiter, Gatti, Montegriffo.

Other computing activities have been carried out during 2003. Among them:

In 2002 and 2003 a project financed by the European Union in the framework of the ``Information Society and Technologies (IST)" programme was carried out by de Ruiter as a collaboration between the OAB, IRA and CINECA (all at Bologna), the IFCTR (Milano), the Observatory of Catania, and ASTRON (the Netherlands). The aim of this project was to produce a software package for displaying and manipulating three dimensional data sets. The data sets may be 3D images (i.e. gridded data), or lists of data with three or more variables. The package can handle a wide variety of data formats (including FITS files). The project was successfully completed at the end of 2003. A User Guide is available on-line; a paper version is in press.

Gatti continues the collaboration with the Administration of the Observatory providing the informatic support, nowaday essential to the administrative work, and writing specific programs and procedures.

Montegriffo has developed original software for data analysis in digital photometry in crowded fields.

• CATAPACK is a package for management and manipulation of photometric catalogues of stellar fields, particularly suitable for the determination of accurate astrometric solutions: it has been conceived for the preparation and execution of some Observatory scientific programs such as that of the ItalFLAMES Consortium. This package has been designed to be user-friendly and portable on different platforms (Compaq TrueUnix64, Linux, HP, Sun). Written in the ANSI C language, it is provided with autoconfiguration tools based on GNU automake, autoconf and libtool. The core of the package is represented by two programs: CataXcorr e CataComb.
• CataXcorr (Catalogues Cross Correlator) performs cross correlations and coordinate transformations between an arbitrary number of input catalogues. The program is able to find accurate transformations with a common reference system of linear or spherical coordinates, independently of scale differences, axis rotation or inversion, producing astrometric solutions and relative calibrations. The main characteristic is its high degree of automatization thanks to a pattern recognition algorithm based on identifications of similar triangles. The program has a GUI based on the Gnu GTK library that permits complete user control over the algorithms and an immediate check of results. Spherical coordinate projections are realized through Mark Calabretta's WCSLIB libraries; coordinate models conform to recent FITS standards and by a simple auxiliary script it is possible to put all relevant WCS information in the original fits images from which catalogs have been produced.

• CataComb (Catalogues Combiner) is a program that allows to combine an arbitrary number of input catalogs producing a single output catalog with the desired quantities. Objects from input catalogs can be associated by means of a cross-correlation table produced by CataXcorr or by identification number. CataComb's main characteristic is flexibility: free format for input catalogs, high number of files that can be processed simultaneously (up to 64), output content controlled by a very simple and intuitive syntax thanks to a parser able to interpret arithmetic and logical expressions of high complexity.

CataPack is currently used and tested by many astronomers at various INAF Institutes (e.g. OAB, TNG and Rome Observatory). OAB, as a member of the ItalFLAMES Consortium, was involved in the ``Science Verification" stage of the instrument: the requested accuracy for observation targets was of 0.2 arcsec only. Astrometry derived with CataXcorr in severely crowded star fields has been successfully tested during the 1st GTO phase (May 2003) when all given targets ($\sim250$ stars in M22; $\sim800$ stars in Omega Cen and 130 stars in NGC2808) were correctly observed. GUI for CataComb is under development: it can produce fast plots of diagrams and maps, mean ridge lines and bestfit relations and also density maps (Hess diagrams and density contour plot).