1. Pisa, 4 May 2009 Alessandro Spagna A new kinematic survey (from GSC-II and SDSS-DR7) to study the stellar populations of the Milky Way Alessandro Spagna 1, Beatrice Bucciarelli 1, Mario Lattanzi 1, Paola Re Fiorentin 2, Richard Smart 1 (1 - INAF-OATo, 2 – Univ. of Ljubljana)

2. Pisa, 4 May 2009 Alessandro Spagna Astrometry (positions, proper motions, Trigonometric parallaxes) Photometry (stellar classification, Photometric distances) Spectroscopy (Radial velocities, Chemical abundances) Surveys of galactic stellar populations: basic ingredients

3. Pisa, 4 May 2009 Alessandro Spagna

4. Pisa, 4 May 2009 Alessandro Spagna

5. Pisa, 4 May 2009 Alessandro Spagna SDSS DR7 Imaging 11,660 deg 2 of imaging data (1/4 of the sky) 357 million objects Photometry ugriz, 14.0<g<22.2 Abazajian et al. 2009 ApJS, in press Spectroscopy 300,000 galactic stars 3850 < < 9000 A, R = 2000 Radial velocities, 10 km/s accuracy Yanny et al. 2009 ApJ, 127, 4377

6. Pisa, 4 May 2009 Alessandro Spagna Guide Star Catalog II - Database All sky archive from the digitized Palomar and Anglo Australian Obs. Schmidt surveys 1 billion objects positions ICRF, classification (stellar/extended sources) B J V 12 R F I N photographic photometry, B<22 Multi-epoch positions, 1950< Epoch < 2000 Lasker, Lattanzi, McLean et al, AJ, 136, 735 GSC 2.3 counts: objects per deg 2 down to R F =20.

7. Pisa, 4 May 2009 Alessandro Spagna Proper motions Multi-epoch positions from SDSS and GSC- II (mainly POSS-I and POSS-II) available in the GSC-II DB mirror in Torino. Database structure: HEALPix tesselation level 6, i.e. 49152 regions (0.839 deg 2 ) Transformations from (X,Y) plate coordinates to standard coordinates ( ,  ) computed for HEALPix level 7 (27’x27’) Relative proper motions Absolute p.m. computed with zero-point derived from extra-galactic sources (SDSS classification adopted)

8. Pisa, 4 May 2009 Alessandro Spagna Proper motions Proper motion formal errors:  (µ) = 2-3 mas/yr Proper motions accuracy (test based on 235 QSOs towards the galactic anticenter): Torino catalog = 0.13 ± 0.20 mas/yr = 0.10 ± 0.18 mas/yr  (µ  cos  ) = 3.0 mas/yr  (µ  ) = 2.7 mas/yr Munn’s catalog = 0.07 ± 0.29 mas/yr = 1.07 ± 0.31 mas/yr  (µ  cos  ) = 4.5 mas/yr  (µ  )= 4.8 mas/yr ,  (arcsec) vs.  t (yr) SDSS POSS-II POSS-I p.m. solution from Spagna et al. (1996)

9. Pisa, 4 May 2009 Alessandro Spagna Stellar astrophysical parameters ( Teff, log(g), [Fe/H] ) Methods: SDSS pipeline (SSPP) Lee et al 2008, AJ, 136, 2022 Supervised feed forward neural network (ANN) Re Fiorentin et al 2007, A&A, 467, 1374 Precision :  (Teff) = 130K  (log g) = 0.21  [Fe/H] = 0.11 External comparisons by Allende Prieto et al 2008, AJ, 136, 2070

10. Pisa, 4 May 2009 Alessandro Spagna Stellar astrophysical parameters E(Teff)=0.083 E(log g)=0.31 E(Fe/H)=0.25

11. Pisa, 4 May 2009 Alessandro Spagna Photometric distances Method : 1. Magnitude correction: extinction maps of Schlegel et al. (1998). 2. Photometric parallax: absolute magnitude from Eq. 1 of Ivezic et al (2008), calibrated for FGK (sub)dwarfs with [Fe/H]< -0.5.

12. Pisa, 4 May 2009 Alessandro Spagna SDSS - GSC-II catalog ______________________________________________________________ Object Number* ugriz (µ ,µ  ) Teff, log g, [Fe/H] Vr d UVW mag mas/yr K dex dex km/s kpc km/s ______________________________________________________________________________________________ 41,551,644 sources X X 151,711 stars X X X X X X 30,700 FGK dwarfs** X X X X X X X X ______________________________________________________________ * Area: 9000 deg2 ** Kinematic sample: 4500 3.5, [Fe/H]< -0.5, d < 3 kpc

13. Pisa, 4 May 2009 Alessandro Spagna Kinematics & Chemical properties: overview

14. Pisa, 4 May 2009 Alessandro Spagna Kinematics & Chemical properties: overview

15. Pisa, 4 May 2009 Alessandro Spagna From Re Fiorentin et al (2005) Kinematics & Chemical properties: stellar streams

16. Pisa, 4 May 2009 Alessandro Spagna Kinematics & Chemical properties: overview -1< [Fe/H] < -0.5 -1.0< [Fe/H] < -1.5

17. Pisa, 4 May 2009 Alessandro Spagna Kinematics & Chemical properties: overview -2.0< [Fe/H] < -1.5 [Fe/H] < -2.0

18. Pisa, 4 May 2009 Alessandro Spagna CONCLUSIONS We have produced a new proper motion survey covering 9000 deg 2 based on the multi-epoch positions derived SDSS – DR7 combined with the plate material from the GSC-II database. Accurate absolute proper motions (µ ,µ  ) have been computed for 40 million sources down to magnitude g~22 (r~20). Proper motion errors attain 2-3 mas/yr. Stellar astrophysical parameters (Teff, log g, [Fe/H] ) have been (re)estimated for the SDSS spectroscopic sample by means of updated ANN methods. Full astrometric, photometric, and spectroscopic measurements are available for 150,000 stars. Photometric distances and 3D velocities (UVW) have been computed for FGK (sub)dwarfs with [Fe/H]< -0.5. A kinematic sample of 30,700 tracers within 3 kpc from the Sun has been extracted and will be used to (1) study the kinematic properties of the thick disk and inner halo and (2) search for members of known/new kinematic substructures produced by past merging events.