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The AMBRE Project
Institute of Astronomy / Observatoire de la Cte d'Azur
5th September 2012, IoA
Galactic Archaeology with the ESO stellar archive
C. Clare Worley
5th December 2012 AMBRE Presentation 2
Presentation Summary
Galactic Archaeology & Stellar Classification
The AMBRE Project
Galactic Archaeology with the FEROS archived spectra
5th December 2012 AMBRE Presentation 3
Galactic Archaeology
The exploration of large spectral datasets for underlying structures and
populations within the Galaxy in order to create a chemical and kinematic
chart with which to test theories of galactic formation & evolution.
Tracing the fossil record within the Milky Way
Key Characteristics:Position, Direction, Velocity, Age, Temperature, Gravity, Chemical Composition
5th December 2012 AMBRE Presentation 4
The Gaia-ESO Survey
A census of a thousand million stars in our GalaxyThe Gaia Mission
300,000 stars sampling all major components of the Milky Way First homogeneous overview of the distributions
of kinematics & elemental abundance
Revolutionise our understanding of Galactic and Stellar Evolution
5th December 2012 AMBRE Presentation 5
Stellar Parametrisation
CLASSICAL DETERMINATION:
Measurement of individual spectral line strengths Atomic/Molecular linelists, Stellar Atmospheric models,
Radiative transfer code Curve of Growth, Spectrum Synthesis Too time consuming for large samples
47 Tuc NGC 6388 NGC 362
50 stars in 3 globular clusters
Worley et al. 2008, 2009, 2010
25 million stars in the Milky Way
?
Effective Temperature: Teff Surface Gravity: log g Metallicity: [Fe/H] or [M/H] (global) Chemical Abundances: [X/Fe] e.g. [/Fe]: =Mg,Si,Ca,Ti...
5th December 2012 AMBRE Presentation 6
Automated Stellar ParametrisationOptimisation Methods:
Minimum distances, Genetic algorithms, Gauss-Newton methodPattern Recognition Methods: Artificial Neural Networks, Support Vector Machines, Decision Trees
Projection on set Vectors: Principal Component Analysis
MATISSE: MATrix Inversion for Spectrum SynthEsisRecio-Blanco, Bijaoui, de Laverny (2006); Bijaoui, Recio-Blanco, de Laverny (2008)
Developed at Observatoire de la Cote d'Azur primarily for the Gaia mission Local multi-linear regression method B vectors reflect sensitivity of key parameters ( = Teff; log g; [M/H]; [/Fe]) Based on High Resolution Optical Synthetic Spectra Grid (de Laverny et al. 2012)
5th December 2012 AMBRE Presentation 7
The AMBRE Project
Worley et al. 2012, A&A, 542, 48,
5th December 2012 AMBRE Presentation 8
The AMBRE ProjectArchologie avec Matisse: aBondances dans les aRchives de l'Eso
ESO Spectrograph Resolving Power Spectral Domain Approximate No. archived spectra
FEROS 48,000 350nm - 920nm 20,000HARPS 115,000 378nm - 691nm 125,000UVES 40,000 to 110,000 300nm - 1100nm 100,000
Flames/GIRAFFE 5,600 to 46,000 370nm - 900nm >100,000Total Sample >350,000
This extensive dataset covers a large range of wavelengths and resolutions, including the wavelength domain and resolutions of Gaia RVS.
This is a unique opportunity to carry out comprehensive testing of MATISSE which is essential to its preparation for use in the Gaia Mission (GSP-spec).
ESO/OCA project: 2009 - 2012
Collaborators: P. de Laverny, A. Recio-Blanco, V. Hill,C. Ordenovic, F. Guitton, J.C. Gazzano, M De Pascale and A. Bijaoui
5th December 2012 AMBRE Presentation 9
Key Objectives for the AMBRE ProjectESO: Advanced data products for ESO archive
Homogeneous determination of stellar parameters for archived spectra Key information for each spectra in the ESO database Available to the entire astronomical community ESO Archive
OCA: Essential testing of MATISSE for GSP-spec & Gaia Gaia RVS wavelengths and resolutions Large scale dataset of real stellar spectra Extensive error analysis prior to Gaia's launch
Galactic Archaeology: Studies of the Milky Way Creation of a galactic chemical chart Selection of specific stellar sample, i.e. halo, thick disk, thin disk... Kinematic & chemical analysis of homogeneous samples
5th December 2012 AMBRE Presentation 10
The AMBRE:FEROS Analysis
FEROS Targets in Galactic Coordinates
Majority of Southern Sky is sampled
FEROS: Instrument Resolution ~ 48,000
Wavelengths 350nm to 920nm
No. Archived Spectra 21551
No. Stars ~ 6285
MATISSE SET-UP: 17 Wavelength Regions: Mg triplet (~5160 ), H (4861 )
1500 from 4000 to 7000 Synthetic Grid & B Functions at Resolution ~15,000
5th December 2012 AMBRE Presentation 11
Comparison to literature values (SIMBAD, PASTEL, S4N...)
Radial Velocity determinationVrad, VsiniError estimatePreferred-mask parameters
Spectral Processing AWavelength selectionNormalisationCosmic ray removalSignal-to-noiseConstant Spectral FWHM
Spectral Processing BSpectral Processing ARadial Velocity correctionMeasured Spectral FWHM
MATISSEStellar parameters (Teff, log g, [Fe/H], [/Fe])Synthetic spectra
Spectral Processing C
Modified Spectral Processing BNormalisation using synthetic spectra
Select alternate: Radial VelocityNormalisation
Final Stellar parametersFinal Radial Velocity
Final Normalised SpectraFinal Synthetic Spectra
YES NO
AMBRE:FEROS Analysis Pipeline
Tests for:Convergence?Goodness of fit? (2)
MATISSEStellar parametersTests
5th December 2012 AMBRE Presentation 12
FEROS Validation: Homogeneous Reference Samples
5th December 2012 AMBRE Presentation 13
Radial Velocity Comparison
S4N Gaia RVS Standards
Vrad : Cross-correlation of observed spectrum with binary masks(Private communication, C. Melo)
5th December 2012 AMBRE Presentation 14
PASTEL Analysis: Effective Temperature
5th December 2012 AMBRE Presentation 15
PASTEL Analysis: Surface Gravity
5th December 2012 AMBRE Presentation 16
PASTEL Analysis: Metallicity
5th December 2012 AMBRE Presentation 17
S4N and Bensby et al 2003: [/Fe]
5th December 2012 AMBRE Presentation 18
Stellar Parameters for the ESO: FEROS archived spectraNo. of FEROS archived spectra = 21551No. of spectra analysed in SPC = 19181No. of spectra rejected = 15043No. of spectra accepted = 6508 (~3087 stars)
Rejection Criteria I: 2370 spectra prior to SPC
Extreme Emission Features (nova), Extremely Noise Spectra, Poor Normalisation, Missing orders
Rejection Criteria II: 12673 spectra after SPC
Radial Velocity Determination Errors and spectral FWHM
Mainly hot/fast rotating stars: outside limits of Synthetic Grid (FGK stars)
5th December 2012 AMBRE Presentation 19
FEROS Spectra: The Parameters6508 spectra 3087 stars 30.2 % of archived sample
5th December 2012 AMBRE Presentation 20
Galactic Archaeology with the ESO:FEROS Archived Spectra
5th December 2012 AMBRE Presentation 21
FEROS Stars: Cross-matching Catalogues Proper Motions & Apparent Magnitudes (V, B, J, K ) (PPMXL)
Distances
1 Hipparcos new reduction (van Leeuwen 2007)
2 Absolute Magnitudes using Isochrones: MV, MB, MJ, MK
Kordopatis et al, 2011a&b
& Interstellar reddening from Theoretical Colours
Gazzano et al. 2010, 2012; Gonzalez et al, 2009
D = 100.2(m M +5) ZGC = Z + Dsinb
Distance from Sun & above Galactic Plane
5th December 2012 AMBRE Presentation 22
PPMXL: V, B, J, K, Proper Motions Hipparcos: V, B-V, Parallaxes, Proper Motions
FEROS Stars: Photometry
PPMXL
Hipparcos
5th December 2012 AMBRE Presentation 23
FEROS Stars: Metallicity Distribution
5th December 2012 AMBRE Presentation 24
Disk Stars: Metallicity Gradients?
FEROS PPMXL SampleRGC, ZGC ~ 1.5 kpc
Dwarfs Not useful for gradients Useful as Volume-limited,
Local Solar Neighbourhood
Giants Dispersed to higher Z More metal-poor
(pc) (pc)
(pc) (pc)
5th December 2012 AMBRE Presentation 25
Chemically & Kinematically Characterised Stellar Sample in the Local Solar Neighbourhood
Stellar Populations: Thick & Thin Disk
Total (radial,vertical) kinetic energyvs
rotational energyThin Disk: < ~50kms-1Thick Disk: ~50kms-1 ~150kms-1Halo: > ~150kms-1 (Bensby 2009)
5th December 2012 AMBRE Presentation 26
Open Clusters: Metallicity Gradient107 stars (147 spectra) over 26 open clusters.
1. Star Coords < 0.5o of cluster centre,
2. Star Vrad < 2 kms-1 of cluster Vrad.
Other Studies:Pedicelli et al. 2009Haywood 2008Chen et al. 2008
5th December 2012 AMBRE Presentation 27
Galactic Archaeology: SN Pollution in Milky Way
SN Type II
SN Type Ia
Comparison to Bensby et al. (2003)[/Fe] to [M/H]with log g > 3.4 dex.
Dwarfs, Sub-Giants
Supernova Type II:-element production
Supernova Type Ia:Fe production
Change in regime from SN Type II to SN Type Ia as pollution source.
21 Thick Disk45 Thin Disk
5th December 2012 AMBRE Presentation 28
SummaryGalactic Archaeology is a rapidly developing field of research
Wealth of data from large scale surveys Advances in automated analysis Development of crucial calibration datasets
The AMBRE Project takes advantage of the pre-existing large spectral datasets in the ESO Archive
Accepted parameters for 30.2% of FEROS spectra Recycling of archive spectra UVES, HARPS analyses almost complete Archive-based galactic chemical chart
5th December 2012 AMBRE Presentation 29
Acknowledgements
Observatoire de la Cte d'Azur European Southern Observatory Centre National d'Etudes Spatiales
5th December 2012 AMBRE Presentation 30
11th September 2012 AMBRE Presentation 31
MATISSE: MATrix Inversion for Spectral SynthEsis
Stellar parameters ( = Teff, log g, [M/H], individual chemical abundances) are derived by the projection of an input observed spectrum O() on a vector function B().
The B() function is an optimal linear combination of theoretical spectra S() calculated from a synthetic spectra grid (the learning phase).
Recio-Blanco, Bijaoui, de Laverny (2006); Bijaoui, Recio-Blanco, de Laverny (2008)
B()Oi()
The B() function reflects the sensitivity of the particular spectral regions to the parameter in question, .
Local multi-linear regression method
i Si()
i
11th September 2012 AMBRE Presentation 32
The Grid of High Resolution Synthetic Spectra
~16000 synthetic spectra Optical domain: 3000 - 12000
MARCS model atmospheres (Gustafsson et al., 2010) Teff : 2500 8000 K log g : 0.0 +5.0 dex [M/H] : -5.0 +1.0 dex [/Fe] : -0.4 +0.8 dex
Molecular line lists from Bertrand Plez
Atomic line lists : depending on the analysis grid
MATISSE TRAINING PHASEB functions are generated corresponding to each point in the spectral grid for each parameter
Computed using OCA Mesocentre ~ 50,000hrs computing time
de Laverny et al. 2012, A&A, 544, 126
5th December 2012 AMBRE Presentation 33
MATISSE: Using the B functions
B0: Teff(0), log g(0), [M/H](0)
Bi: Teff(i), log g(i), [M/H](i)
BBi i B Bi -1i -1
Final: Teff, log g, [M/H]
Teff
log g
[M/H]
3D Representation of Synthetic Grid
11th September 2012 AMBRE Presentation 34
MATISSE: Java InterfaceInputs Comparison of Synthetic and Observed Spectra
Quality flag
11th September 2012 AMBRE Presentation 35
The FEROS Archived Spectra: Normalisation
SPB
SPB Final
SPCi=0
11th September 2012 AMBRE Presentation 36
FEROS Spectra: The RejectionsWell-defined CCF vrad 10 km/s
FWHM CCF 50 km/s
SPC
Spectral FWHM 0.8 m Strong line FWHM 8 m
C. Clare Worley Automated Stellar Classification & Galactic Archaeology Preparing MATISSE for the ESA Gaia MissionAutomated Stellar Classification & Galactic ArchaeologyGlobular Clusters & Large Scale SurveysSlide 4Slide 5Slide 6Slide 7AMBRE Archologie avec Matisse: aBondances dans les aRchives de l'EsoKey Objectives for Gaia, ESO and Galactic ArchaeologySlide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28Slide 29Slide 30Slide 31Slide 32Slide 33Slide 34Slide 35Slide 36