Gaia A Stereoscopic Census of our Galaxy http://www.cosmos.esa.int/web/gaia December 2015 Gaia: Design Considerations Astrometry (G < 20 mag): completeness to 20 mag (on-board detection) 109 stars accuracy: 26 arcsec at G=15 mag (Hipparcos: 1 milliarcsec at 9 mag) scanning satellite, two viewing directions global accuracy, with optimal use of observing time principle: global astrometric reduction (as for Hipparcos) Photometry (G < 20 mag): astrophysical diagnostics (low-dispersion photometry) + chromaticity Teff ~ 100 K, log g, [Fe/H] to 0.2 dex, extinction (at G=15 mag) Radial velocity (GRVS < 16 mag): accuracy: 15 km s-1 at GRVS=16 mag application: third component of space motion, perspective acceleration dynamics, population studies, binaries spectra for GRVS < 12 mag: chemistry, rotation principle: slitless spectroscopy in Ca triplet (845-872 nm) at R = ~10,800 2
Gaia: Complete, Faint, Accurate Hipparcos Gaia Magnitude limit Completeness Bright limit 12 mag 7.3 9.0 mag 0 mag Number of objects 120,000 Effective distance limit 1 kpc 20 mag 20 mag 3 mag (assessment for brighter stars ongoing) 47 million to G = 15 mag 360 million to G = 18 mag 1192 million to G = 20 mag 50 kpc Quasars Galaxies Accuracy
1 (3C 273) None 1 milliarcsec Photometry Radial velocity Observing 2-colour (B and V) None Pre-selected 500,000 1,000,000 7 arcsec at G = 10 mag 26 arcsec at G = 15 mag 600 arcsec at G = 20 mag Low-res. spectra to G = 20 mag 15 km s-1 to GRVS = 16 mag Complete and unbiased 3 Stellar Astrophysics Comprehensive luminosity calibration, for example:
distances to 1% for ~10 million stars to 2.5 kpc distances to 10% for ~100 million stars to 25 kpc rare stellar types and rapid evolutionary phases in large numbers parallax calibration of all distance indicators e.g., Cepheids and RR Lyrae to LMC/SMC Physical properties, for example: clean HertzsprungRussell diagrams throughout the Galaxy Solar-neighbourhood mass and luminosity function e.g., white dwarfs (~400,000) and brown dwarfs (~500) initial mass and luminosity functions in star-forming regions luminosity function for pre-main-sequence stars detection and dating of all spectral types and Galactic populations detection and characterisation of variability for all spectral types 4 One Billion Stars in 3D will provide in our Galaxy
the distance and velocity distributions of all stellar populations the spatial and dynamic structure of the disk and halo its formation history a detailed mapping of the Galactic dark-matter distribution a rigorous framework for stellar-structure and evolution theories a large-scale survey of extra-solar planets (~7,000) a large-scale survey of Solar-system bodies (~250,000) and beyond definitive distance standards out to the LMC/SMC rapid reaction alerts for supernovae and burst sources (~6,000) quasar detection, redshifts, microlensing structure (~500,000) fundamental quantities to unprecedented accuracy: to 210-6 (210-5 present) 5 Exo-Planets: Expected Discoveries Astrometric survey: monitoring of ~150,000 FGK stars to ~200 pc detection limits: ~1MJ and P < 10 years complete census of all stellar types, P ~ 2-9 years masses, rather than lower limits (m sin i) multiple systems measurable, giving relative inclinations Results expected:
~2000 exo-planets (single systems) ~300 multi-planet systems displacement for 47 UMa = 360 asas orbits for ~1000 systems masses down to 10 MEarth to 10 pc 1.2 (") Photometric transits: ~5000 1/07/02 1 0.8 1/01/03 1/07/01 0.6 0.4 Plante : = 100 mas P = 18 mois 0.2 0 1/07/00 1/01/02 1/01/01
1/01/00 0 Figure courtesy 0.2 Franois 0.4 Mignard0.6 cos (") 0.8 6 1.0 Studies of the Solar System Asteroids etc.: deep and uniform (G=20 mag) detection of all moving objects ~250,000 objects observed, mainly main-belt asteroids orbits: 30 times better than present, even after 100 years spin-axis direction, rotation period, shape parameters for majority taxonomy/mineralogical composition versus heliocentric distance diameters for ~1000 to 20%, masses for ~150 to 10% Trojan companions of Mars, Earth, and Venus Kuiper-Belt objects: ~50 objects to G=20 mag (binarity, Plutinos) Centaurs: ~50 objects Near-Earth Objects: Amors, Apollos and Atens (4389, 5156, 811 known today) ~1600 Potentially Hazardous Asteroids (PHA) >1 km predicted (1435 currently known) detection limit: 260-590 m at 1 AU, depending on albedo
7 Light Bending in Solar System Light bending in microarcsec, after subtraction of the much larger effect by the Sun Movie courtesy Jos de Bruijne 8 Satellite and System ESA-only mission Launch: 19 December 2013 Launcher: SoyuzFregat from French Guiana Orbit: L2 Lissajous orbit Ground stations: Cebreros, New Norcia + Malarge Lifetime: 5 years (1 year potential extension) Downlink rate: 4 - 8 Mbps 9 Figure Soyuz: Arianespace; figure Gaia: ESA - C. Carreau Payload and Telescope Two Sic primary mirrors 1.45 0.50 m2 at 106.5
Rotation axis (6h) Basic-Angle-Monitoring (BAM) system SiC torus (optical bench) Combined Focal-Plane Assembly (FPA) with 106 CCD detectors Superposition of two Fields of View (FoV) Figure courtesy EADS-Astrium Radial-Velocity Spectrometer (RVS) 10 Figure courtesy Alex Short Focal Plane 104.26cm 42.35cm Basic Angle Monitor
Basic Angle Monitor Red Photometer CCDs Wave Front Sensor Blue Photometer CCDs Wave Front Sensor Radial-Velocity Spectrometer CCDs Star motion in 10 s Sky Mapper CCDs Astrometric Field CCDs Total field: - active area: 0.75 deg2 - CCDs: 14 + 62 + 14 + 12 (+ 4) - 4500 x 1966 pixels (TDI) - pixel size = 10 m x 30 m = 59 mas x 177 mas
Sky mapper: - detects all objects to G=20 mag - rejects cosmic-ray events - field-of-view discrimination Astrometry: - total detection noise ~ 4 e- Photometry: - spectro-photometer - blue and red CCDs Spectroscopy: - high-resolution spectra 11 - red CCDs On-Board Object Detection Requirements: unbiased sky sampling (magnitude, colour, resolution) all-sky catalogue at Gaia resolution (0.1 arcsec) to G~20 mag does not exist Solution is on-board detection: no input catalogue or observing programme good detection efficiency to G~21 mag Gaia will therefore detect:
variable stars (eclipsing binaries, Cepheids, etc.) supernovae: ~6,000 gravitational-lensing events: ~1000 photometric and ~100 astrometric Solar-system objects, including near-Earth asteroids and Kuiper-Belt objects 12 Sky-Scanning Principle Spin axis Scan rate: Spin period: 45o to Sun 60 arcsec s-1 6 hours 13 Figure ESA Photometry Measurement Concept (1/2) Blue photometer: 330 - 680 nm Red photometer: 640 - 1050 nm 14 Figure courtesy EADS-Astrium Photometry Measurement Concept (2/2) 700
0 0 5 10 15 20 AL pixels 25 30 35 14 Red photometer 900 12 850 10
800 8 750 6 700 4 650 2 600 spectral dispersion per pixel (nm) . 550 950 wavelength (nm) wavelength (nm) 30 spectral dispersion per pixel (nm) . Blue photometer
600 0 0 5 10 15 20 25 30 35 AL pixels RP spectrum of M dwarf (V = 17.3 mag) Red box: data sent to ground White contour: sky-background level Colour coding: signal intensity 15 Figures courtesy Anthony Brown Radial-Velocity Measurement Concept (1/2)
Spectroscopy: 845 - 872 nm (resolution ~10,800) 16 Figure courtesy EADS-Astrium Radial-Velocity Measurement Concept (2/2) Field of view RVS spectrograph CCD detectors RVS spectra of F3 giant (V = 16 mag) S/N = 7 (single measurement) S/N = 130 (summed over mission) 17 Figures courtesy David Katz Data-Reduction Principles Scan width = 0.7 Sky scans (highest accuracy along scan) Figure courtesy Michael Perryman 1. Object matching in successive scans 2. Attitude and calibrations are updated
3. Objects positions etc. are solved 4. Higher-order terms are solved 5. More scans are added 18 6. System is iterated Scientific Organisation Gaia Science Team (GST): 7 members + ESA Project Scientist + DPAC Executive Chair Scientific community: organised in Data Processing and Analysis Consortium (DPAC) 450+ scientists in 20+ countries active at some level GREAT network for post-mission science exploitation Community is active and productive: regular Science Team / DPAC meetings growing archive of scientific and processing-software reports advance of algorithms, calibration models, accuracy models, etc. Data-distribution policy: final catalogue ~2022 intermediate catalogues defined intermediate releases starting 2016 with positions; parallaxes and proper motions will be added in 2017
science-alerts data released immediately no proprietary data rights 19 Data Processing Concept 20 19 93 19 94 19 95 19 96 19 97 19 98 19 99 20 00 20 01 20 02 20 03 20 04 20
Office of Nuclear Security. International Atomic Energy Agency. Points to make: these are moderate activity sources that, while not cat-1, must be considered as in need of significant care when shipping. All applicable regulations for transport should be followed.
Within the 'City' you will find a futuristic opera house, planetarium, IMAX cinema, vast science museum, botanical gardens and a huge aquarium Beaches: Mexico Los animales Los penguinos: Argentina, Chile, Peru, Ecuador * *
Ma Famille La famille de Mr. Ford. Voici Moi. Je m'appelle Bennett. ... Je suis intelligent. J'aime le hockey, les jeux de vidéo, et les comics. Je suis de Prince Albert, Saskatchewan. Voici Ma Femme. Elle s'appelle Lisa. Elle a...
Oracle Purchasing & Oracle iSupplier Portal provide the capability to specify complex payment terms, execute on the contract, and report & track progress against the Progress Payment Schedule. Oracle Payables provides the functionality to record invoices using the complex payment...
You can use the statistical functions on your calculator to find the equation of the regression line - this is the name of the calculated line of best fit. The equation of the regression line in the graph to the...
Circular Motion Newton's Second Law and circular motion Serway and Jewett 6.1, 6.2 Review: Circular Motion Kinematics Particle dynamics : nothing new There is no "centrifugal force" has a radial component as well as (perhaps) a tangential component Example: Pendulum...
For each hat that you are using prepare individual easel pads with a hat & category name at the top. For example: Red (Emotions), White (Facts), Yellow (Benefits), Green (Creativity), Black (Judgement) Hang easel pad papers on wall in your...
Part One/Two: US/NC MapsYou will have to correctly identify places and features of US and NC map. Part Three: Key terms. Fill in the Blank with a Word Bank. Please make sure you are using your study guide to review...
Ready to download the document? Go ahead and hit continue!