Thesis Defense : "Astrostatistics for Luminosity Calibration in the Gaia Era"

  • Author/PhD Student: Max Palmer
  • Date: 13 January 2015
  • Hour: 12:00
  • Place: Sala de Graus (Aulari) Facultat de Física
  • Tribunal:​
    • President: Dr. Jos de Bruijne
    • Secretary: Dr. Claus Fabricius
    • Vocal: Dr. Gisella Clementini
    • Substitutes: Dr. Anthony Brown; Dr. Jordi Torra Roca​
    • Directors: Dr. Francesc Xavier Luri Carrascoso; Dr. Frédéric Arenou; Dra. Francesca Figueras Siñol (Tutora)
  • Abstract: The European Space Agency astrometric satellite Gaia was launched in December 2013. Having completed its commissioning phase, Gaia is transmitting data to Earth that will lead to the creation of an
    astrometric catalogue of more than 10^9 celestial objects. To prepare
    for the use of the Gaia catalogue, we define a set of statistical methods for the correct use of trigonometric parallax data. Direct use of the distance obtained from the inverse of the parallax is problematic, due to the possible effect of numerous known statistical biases and selection effects. We provide a set of methods which utilise parallax information correctly, in order to calibrate the absolute luminosity of several objects of interest: normal stars, variable stars, open clusters, and the Magellanic Clouds. The methods make extensive use of statistical modelling and Bayesian statistics in order to treat the data correctly and without bias.


Friday, 19 December, 2014