The Gaia Archive. Center Forum, Heidelberg, June 10-11, Stefan Jordan. The Gaia Archive, COSADIE Astronomical Data

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1 The Gaia Archive Astronomisches Rechen-Institut am Zentrum für Astronomie der Universität Heidelberg 1

2 2 Gaia and beyond

3 Progress with Gaia 3 HIPPARCOS Gaia accuracy x 50 sensitivity x # of stars x 10000

4 Gaia s schedule 1993: First proposal to ESA 2000: accepted as Cornerstone Mission 2006: Begin of the industrial phase 2007: Preliminary Design Review Ready to launch, transport to Kourou at July 11? September 2013?: Launch After commissioning: Begin of regular measurements 2018: End of nominal measurements (5 years) 2021: Publication of final catalogue? Intermediate catalogues will come 4

5 Gaia s main goals Positions, Parallaxes, and proper motions of 1 billion stars All stars down to 20 th magnitude micro arc seconds accuracy at 15 th magnitude Precise photometry (low resolution spectra) for 1 billion stars High-res infrared spectra for 50 to 100 million stars Additional dimensions : Radial velocity Spectral type (log g, Teff) Chemical abundances Rotational velocities 5

6 Hardware is ready for launch 6 6

7 One of the main mirrors 7

8 Launch Vehicle Soyuz-Fregat 47 meter height Launch from Sinnamary in French Guyana September 19, 2013? French Guiana 21st October 2011: Soyuz lifted off successfully for the first time from Europe's Spaceport in French Guiana with the same configuration as for the Gaia launch in It carried the first two Galileo In-Orbit Validation satellites. 8

9 Orbit of Gaia (Lagrangian point L2) 9 Movie: The Gaia Mission Spanish Participation,

10 Launch Movie: The Gaia Mission Spanish Participation, 10

11 Torus and Instruments Movie: The Gaia Mission Spanish Participation, 11

12 Scanning Law Animation: Berry Holl, Lund 12

13 Main astrometric parameters position at reference epoch ( 0, 0 ) proper motion (µ, µ ) parallax ( ) path of star on the sky 13

14 Blue/red photometer Figure courtesy Anthony Brown DA white dwarf RP spectrum of M dwarf (V=17.3) Red box: data sent to ground White contour: sky-background level Colour coding: signal intensity 14

15 Radial-velocity measurements 15 Field of view RVS spectrograph CCD detectors Figures courtesy David Katz RVS spectra of F3 giant (V=16) S/N = 7 (single measurement) S/N = 130 (summed over mission)

16 Precision of parallaxes 16

17 The Milky Way You are here The movement of stars in our Galaxy is determined by the gravity of the visible and dark matter. Gaia will probe the galactic potential by studying the movement of one billion stars! 17

18 The Milky Way You are here Stars observed by Gaia (simulation) 18

19 Gaia is a discovery machine galaxies quasars 10 5 extragalactic supernovae (new) asteroids 10 8 binaries disk white dwarfs brown dwarfs planetary systems 19

20 Gaia data For one billion stars (all brighter than G=20) astrometry: positions proper motions parallaxes (distances) low-resolution spectra (colours, energy distributions, λ/δλ 4-32) For about 100 million stars (brighter than G=16) radial velocities high-resolution spectra (λ/δλ 11000) in the near infrared Standard errors an correlations In final catalogue: positions for each CCD transit There is currently no other survey which delivers all sky photometry, astrometry, and spectroscopy 20

21 Gaia data (additional data products) Orbit parameters of binary stars Lightcurves, variability information Classification of stars Astrophysical parameters (T eff, log g, metallicity, rotational velocity) 21

22 Needed 22 Crossmatch with existing catalogues Comparison of observed Gaia data and theoretical models Allowing complicated queries of multi-dimensional data Visualisation of the data (3D, 6D, ) Implementation of specific use cases that have been gathered (science driven) Quality assurance: Correlations between the parameters Identification of spurious features, systematic effects Visualisation Documentation

23 Science Goals Galactic astrophysics: Determination of spatially resolved luminosity and initial mass functions, star formation rates and stellar multiplicity. Three-dimensional mapping of interstellar extinction. Six-dimensional phase space (position + velocity ) data coupled with photometry for very large, magnitude-limited samples. Disentangling the complex relationships between the spatial and kinematic distributions of the stars and their ages and chemical enrichment, which encode the Galactic evolution. Map the galactic potential using the number density and kinematics of tracer stars thus determining the distribution of (dark) matter. Understanding the dynamics of our Galaxy (bar, spiral structure, warp). Reveal the galactic merger history. Stellar astrophysics: Accurate distances to stellar clusters and individual stars covering a very wide range of masses and evolutionary stages Together with multi-wavelength spectrophotometry this provides accurate luminosity calibrations and stringent tests of stellar interior models, model atmospheres and stellar evolution. Discovery and classification of variable stars. For nearby stars: Sensitive survey of (visible or invisible) companion objects, including thousands of exoplanets. 23

24 Science Goals Solar system: Detection and measurement of asteroids down to 20 mag about 15 times per year, to 1 mas accuracy per epoch even for objects close (<45 ) to the sun and at high ecliptic latitudes. Determination of their orbits and physical characteristics (size, spin, shape, taxonomic classification). Masses for about 100 asteroids can be determined from close encounters. Observations of Kuiper Belt objects, where masses may be determined for detected binary objects. Reference frame and experimental relativity: The many accurate positions and proper motions define a dense (>1500 stars per degree) net of reference objects. Direct link to the extragalactic reference frame through quasars (about 500,000) providing a kinematically non-rotating system. At 18 mag positions are good to <1 mas over the 40-year period. Quasar observations also give of the acceleration of the Solar System in a cosmological frame from the secular change in their stellar aberration. General relativity can be tested through the gravitational light bending by the Sun and planets and the perihelion precession for about 300 asteroids. Cosmic Distance Scale: Calibrating nearby standard candles (e.g. Cepheids) in order to determine more accurate distances to galaxies. 24

25 Gaia s schedule September 2013: Launch? After commissioning: Begin of regular measurements Science Alerts Launch+22 months: (α, δ) positions only, G magnitudes, proper motion for stars common with Hipparcos. Release of Ecliptic Pole data. Launch+28 months: Five parameter solution for single stars. Integrated BP/RP photometry. Radial velocities for bright nonvariable stars. 25

26 Gaia s schedule Launch+40 months: Five parameter solution for single stars + orbital solutions for binaries with appropriate periods. Object classification, BP/RP spectra + RVS spectra for well behaving objects. Launch+65 months: Additionally variable star classification, solar system objects, non-single star catalogue. Launch+7 or 8 years: Final catalogue. 26

27 CU9: Gaia Archive A central data base at ESAC (Spain) Several mirrors and specialised data centers All data are immediately public to everyone 27

28 Software to the data Huge data volumes Data is becoming the bottleneck: too big to be moved and replicated Move the logic where the data is. From: Jesus Salgado, June

29 A scientific use case: Statistical plots It must be supported to easily generate statistical plots for the whole data set or selected samples of data. Map/Reduce functions (Hadoop) Hive? Relatively low-level API Steep learning curve Data warehouse system for Hadoop that facilitates easy data summarization, ad-hoc queries, and the analysis of large datasets stored in Hadoop compatible file systems. Map/reduce tasks using a SQL-like language (HiveQL) Custom mappers and reducers may be plugged in 29

30 Positions at ARI/ZAH At the ARI/ZAH we looking for a software developer working on the software support of the scientific exploration of the data from the Gaia satellite as well as its electronic publication. Programming in several programming and scripting languages (C, java, python, ) Design and extension of data base systems. One major task will be the development of a software system allowing the rapid retrieval of spectra matching an input template. The job will further include intensive cooperation with local and international partners from computer science and astronomy. Non-permanent but good chance to work for many years on Gaia data. 30

31 End of talk 31

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