IoW_20131008 - Gaia

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Initial Gaia Source list

The Initial Gaia Source List (IGSL) is envisioned to be a combination of the best optical astrometry and photometry information on celestial objects available today; a snapshot of the sky as we know it before Gaia. Nominally we have attempted to include all objects brighter than magnitude 21 in the expected Gaia G band. We have included publically available large (e.g. >10000 square degrees) catalogues, and some smaller special area catalogues. The Initial Gaia Source List will be used as the starting point for the Gaia Initial Data Treatment, to provide a source identifier (ID) to the objects in the various support catalogues and to provide extra information for the science alerts programme.

In the figure we plot the density of objects included in the IGSL in galactic coordinates. The square grid visible near the plane is due to differing photometric information and completness in the overlap of the Schmidt plates that were used for the PPMXL and GSC23 input catalogues. The bands that traverse the plane are due to extra objects and photometric information from the SDSS surveys.

Image and text: courtesy of R. L. Smart

[Published: 08/10/2013 ]