Mining big data to find new and rare objects in the Universe

le 28 novembre 2025, Natalie Webb, 10h45 à 12h45, salle Jules Verne, OMP, site Belin

Summary: Large surveys such as Gaia, the Sloan Digital Sky Survey (SDSS), GALEX, 2MASS, NVSS, FIRST, XMM-Newton and Chandra, have catalogued many different stars and galaxies. Other more exotic objects can also be found such as black holes, neutron stars and white dwarfs, supernova explosions and gamma-ray bursts and black holes destroying stars. During this seminar I will talk about how to mine such large volumes of data and as an example present the European Space Agencies X-ray satellite XMM-Newton and its X-ray catalogue, 4XMM. I will discuss some of the exotic objects that we have found in the catalogue of more than a million detections, such as intermediate mass black holes, tidal disruption events, ultra-luminous X-ray sources, and pulsars, as well as how we can go about finding other new, rare objects. I will present new and recent surveys that push our data sets into the « big data » domain and I will discuss how we can deal with this enormous influx of data and how machine learning techniques can help.