The Gaia mission: the dawn of Astrometric Cosmology? Status and prospects after 14 months of science operations

[摘要] The concept of precisely gauging a gravity-dominated Universe like ours through the individual observations of its fundamental constituents, the stars, immediately calls astrometry, the oldest quantitative specialty of astronomy, into play. Today, thanks to the launch of the Gaia satellite, astrometry has reached such levels to become a key player in the field of local cosmology and experimental gravitation. Updates on the status of the mission, orbiting in L2 since January 2014 and in nominal observation mode since July 2014, are presented. We also discuss how the astrometric observations from within the gravitational fields of the Solar System can uniquely probe possible deviations from General Relativity and how accurate absolute kinematics at the scale of the Milky Way can, for the first time in situ, account for the predictions of the CDM model for the formation of the Galactic halo.

[发布机构] INAF - Osservatorio Astrofisico di Torino, via Osservatorio 20, Pino Torinese; 10025, Italy^1

[效力级别] 天文学 [学科分类] 天文学(综合)

[关键词] CDM modeling;Gaia mission;GAIA satellite;Galactic halo;General Relativity;Gravitational fields;Science operations;Status and prospect