The sky is full of stars! Gaia and the Virtual Observatory


The ESA (European Space Agency) presented on April 25 the second data collection of the Gaia mission, a project that aims to map our galaxy with unprecedented precision . The published catalog represents the largest star map built to date. This amount of data poses an interesting challenge for the astronomical community: will we be buried by this huge avalanche of data or, on the contrary, do we have the necessary mechanisms to extract the scientific knowledge that these data enclose? Two are the keys to give a positive answer to this question: the 'Big Data' and the Virtual Observatory.

We talk about 'Big Data' when, as with Gaia, the volume of data to be processed exceeds the capacity of the usual software for its management. In these cases, it is necessary to forget about classical methodologies and apply a series of techniques, including data mining and self-statistical developments, which allow for much more profound multidimensional analyzes than the studies to which we are accustomed.

For its part, the Virtual Observatory (VO, according to its acronym in English) is an international initiative that was born towards the year 2000 with the aim of creating a federation of astronomical data files worldwide. INTA, through the Center for Astrobiology (INTA-CSIC), leads and coordinates, since 2004, the activities of the Virtual Observatory. In the framework of the Gaia project, the VO group has focused on the development of two analysis tools that allow astronomers to work quickly and accurately with all the information that, on Gaia objects, exists in the universe of the Virtual Observatory : VOSA and Clusterix.

The Gaia catalog provides information on the brightness of the stars only in three wavelengths. In order to know the fundamental physical parameters of them, it is necessary to complement the Gaia information with brightness measurements at other wavelengths and analyze these data by comparing them with theoretical models. VOSA, developed in the CAB, in collaboration with scientists from the University of Valparaíso (Chile), performs this process automatically for thousands of objects at once.

For its part, the Clusterix tool, also developed by the VO group and in collaboration with the University of Barcelona (ICCUB-IEEC), allows collect all the existing information about movements and distances, visualize it and assign the probability of belonging of a certain object to a cluster. Star clusters are basic structures to understand the birth and evolution of stars and it is expected that Gaia will significantly increase the number of known clusters thanks to Clusterix.

Figure: image of the Milky Way through Gaia's eyes. The map shows the color and brightness of the nearly 1,700 million stars observed by Gaia between July 2014 and May 2016. © ESA / Gaia / DPAC


Fuente: UCC-CAB

Fecha: 2018-05-06


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