Search for multiply-imaged quasars in the Gaia DR2
Langue
en
Communication dans un congrès
Ce document a été publié dans
SF2A, 2019-05-14, Nice.
Résumé en anglais
Gaia was mainly designed for the study of stars in our Galaxy. However, by continuously scanning the entire sky, it also provides informations on all kind of objects that fall in its fields of view, including extragalactic ...Lire la suite >
Gaia was mainly designed for the study of stars in our Galaxy. However, by continuously scanning the entire sky, it also provides informations on all kind of objects that fall in its fields of view, including extragalactic objects. Amongst these extragalactic sources, quasars stand out to be some of the most peculiar objects that Gaia observe. Beside the fact that they play a crucial role in fixing the Gaia Celestial Reference Frame, they also have their intrinsic interest in cosmology. One of their important application occurs when a massive galaxy stands along the line of sight joining the quasar and the observer as, in this case, multiple images of this quasar may form. The time delays measurement between these lensed images then provide a reliable estimation of H0 that is independent of the commonly used cosmic distance ladder. We describe here how the precise relative positions and magnitudes, as provided by Gaia, can be used in order to probe the lensing nature of clusters of objects coming from the Gaia DR2. We present some newly discovered lenses that were spectroscopically confirmed in recent follow-up observations.< Réduire
Mots clés en anglais
Gravitational lensing: strong
Quasars: general
Astrometry
Methods: data analysis
Catalogues
Surveys
Origine
Importé de halUnités de recherche