Self‐Organizing Maps in application to the OGLE data and Gaia Science Alerts

Abstract

The Optical Gravitational Lensing Experiment is long‐term observing project aiming at detection of microlensing events in crowded stellar fields. As a natural by‐product it collects photometric time‐series of millions of variable stars towards the Galactic Centre and in Magellanic Clouds. In November 2008 third phase of the OGLE will conclude its continuous run since 2001. Huge data set gathered with superb quality is one of very few of such kind currently available. Nearly a billion objects towards the Galactic bulge and Magellanic Clouds need to be now investigated and classified into variability classes. Self‐Organizing Map (SOM) is a promising tool for exploring large multi‐dimensional datasets. It is quick and convenient to train in an unsupervised process and as an outcome it produces naturally clustered patterns. Application of SOM to the new OGLE‐III data set will be presented along with the first preliminary results. SOM technique, tested on OGLE data, will be also implemented within Gaia mission...