18 février 2020Unveiling the Milky Way stellar halo distribution with multi-wavelength photometry

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Le 4 octobre 2019
De 10h30 à 12h00

Guillaume Thomas

NRC Herzberg Victoria

 

The stellar halo of our Galaxy is mostly formed by stars that were initially lying in dwarf galaxies and globular clusters, which have been disrupted by the tidal field of the Milky Way. Therefore, due to the long survivability of the structures created by these disruptions, the stellar halo is the best place to probe the accretion history of our Galaxy, and to understand its formation history. I will present recent works that were made using in particular the new deep u-band component of the Canada-France-Imaging Survey (CFIS), in combination with other surveys, such as Pan-STARRS 1 or Gaia. With these observations, it has been possible to study the stellar halo with different type of stars, such as the Blue Horizontal Branch stars (BHBs) or White Dwarfs (WDs). More recently, we developed a machine learning based algorithm that disentangles the giants from the dwarfs, and that obtains their distance and metallicity with high precision, using only their photometry. This new dataset will be extremely valuable for future studies of the stellar halo of the Milky Way, based on different stellar populations. To finish I will present a novel method to generate realistic mocks of stellar halos based on cosmological simulations.