Speaker
Description
CHAIRED by Prof. Yoshinobu Unno (KEK, Japan)
Two of the most challenging questions facing astrophysics and fundamental Physics are the natures of dark energy, the cause of the accelerated expansion of the Universe, and of dark matter, the dominant but unknown form of matter in the cosmos. The European Space Agency’s (ESA) Euclid mission is a satellite dedicated to answering these questions.
Euclid was launched on July 1st, 2023 from Cape Canaveral on a SpaceX Falcon 9 rocket. From its observing station at the Sun-Earth Lagrange point 2 (L2), 1.5 million kilometers from Earth, it will survey the visible extragalactic sky over six years with a 1.2-meter telescope feeding two instruments: a broad-band visible imager (VIS, covering wavelengths 550-900 nm) and a near-infrared spectrometer and photometer (NISP, covering wavelengths 900-2000 nm) equipped with three imaging filters (YJH bands) and a slitless spectrograph (grism). This will give us images at an angular resolution approaching that of the Hubble Space Telescope, but covering 1/3 of the sky, as well as deep near infrared images and spectra - a rich astronomical survey promising important advances and discoveries.
Coupled with visible imaging data from several ground-based telescopes, Euclid will use observations of gravitational lensing - the distortion of distant galaxy images by foreground gravitational fields bending light rays - and of galaxy positions to accurately measure the large-scale distribution of matter (large-scale cosmic structure) and its evolution with time. This will tell us about the evolution, if any, of dark energy and about the nature of dark matter as it creates the large-scale structure of the Universe.
Led by ESA, with contributions from NASA, Euclid is a large international effort already spanning more than a decade.. The Euclid Consortium (EC) is responsible for delivering the two instruments and for the scientific exploitation of the mission. The EC regroups more than 2000 members in more than 15 countries across Europe, Canada, Japan, and the United States.
I will give an overview of the Euclid mission from inception to the present, including its scientific objectives, technical and operations design, and an update on current status and future milestones.
Prof. James G. Bartlett is Distinguished Professor of Physics at the Astroparticule et Cosmologie (APC) Laboratory of the Université Paris Cité. He is a cosmologist working on the origin and evolution of the Universe and its large-scale structure. He is was a member of the Planck satellite mission that measured the cosmic microwave background anisotropies, and is now member of the Euclid space mission and the Rubin/LSST experiment. He is head of the Cosmology and Euclid groups at APC.
