A stereoscopic census of our Galaxy
Aims of the mission To observe the 6D phase-space map of our galaxy with sufficient accuracy to enable the first detailed reconstruction of its history - Positions and kinematics of objects to distances of several tens of kpc need to be studied to enable this: parallaxes, proper motions and radial velocities required
- Classification of each object from photometry
How can this be done? One large survey of all 109 stars brighter than V=20, over 5 to 6 years, covering each object on average about 80 times, providing: - Astrometry, using the Hipparcos principle
- Photometry, using dispersion spectra
- Radial velocities, medium-resolution spectrograph
The payload Focal plane - 0.5 square meter covered with 103 CCDs
- Operating in TDI mode (Time-delayed integration), following images passing over the CCDs
Scientific potential Solar system: census of smaller bodies Nearby stars: Detection of planets Star clusters: observational isochrones Distances globular clusters, LMC & SMC Fundamental physics: reference frames
Planet detection
Double-star detections
Observational Isochrones
The SMC
Phase B2 has started Phase C will start end 2006 Launch scheduled for end 2011 Operations at L2 Mission duration 5 to 6 years Final mission products around 2020
The Gaia Data Processing and Analysis Consortium is in the process of being created - Consists of 8, relatively independent, coordination units, assigned to specific tasks
- 3 data processing, 3 data analysis, and 2 support units
- DPAC executive for coordination and planning of activities
The size of the job Calibration is in first instance towards an internally defined system Extensive iterations required in astrometry, photometry and radial velocities Processing requirements of order 100000 observations per second
UK involvement Photometric data processing - Software developments and implementation
- Cambridge, Leicester, Edinburgh
Radial velocity data processing - Software developments
- MSSL
- Floor van Leeuwen, IoA Cambridge
- Mark Cropper, MSSL
Industry: E2V will manufacture all CCDs
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