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The Exploration of the Solar Neighborhood: Done or Begun?

The Exploration of the Solar Neighborhood: Done or Begun?. C. Allende Prieto University of Texas. T. C. Beers D. L. Lambert Y. Li P. S. Barklem H. Newberg M. Asplund R. Wilhelm B. E. Reddy B. Yanny K. Cunha. Index.

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The Exploration of the Solar Neighborhood: Done or Begun?

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  1. The Exploration of the Solar Neighborhood: Done or Begun? C. Allende Prieto University of Texas T. C. Beers D. L. Lambert Y. Li P. S. Barklem H. Newberg M. Asplund R. Wilhelm B. E. Reddy B. Yanny K. Cunha

  2. Index • The Milky Way: Structure and Evolution • Nearby Stars: the Thin Disk - Thick Disk • Kinematics, Ages and Metallicities of Nearby Stars • Ongoing Projects: BTP1, S4N, Elodie, SDSS … • What’s Next: GAIA & RAVE

  3. Structure of the Milky Way

  4. Thin Disk • Thick Disk • Bulge • Stellar Halo • Dark Halo Picture from Gene Smith’s astron. tutorial

  5. Edvardsson et al. (1993) … and BDP2 (Reddy et al. 2003)

  6. Reddy et al. 2003

  7. NEARBY STARS: Existing data • Vr catalogs • [Fe/H] catalogs • Hipparcos astrometry ~ 30,000 stars with kinematics Just a few thousand with [Fe/H]

  8. Sample B - stars with [Fe/H] & Kinematics

  9. THIN DISK - sample B

  10. Stellar Evolution Isochrones logg Teff=Teff (Mi, Age, Z) Teff logg=logg (Mi, Age, Z)

  11. Age (Gyr) Freeman & Bland-Hawthorn 2002

  12. Sample A -- stars with UVW

  13. Structure in the thin disk - e.g. the Hyades open cluster

  14. Ongoing and Future Surveys of ‘nearby’ (and not so nearby) galactic stars B D P 3 … or B T D P 1 Stars within 15 pc : S4N Sloan Digital Sky Survey -- Thick Disk and Halo RAVE

  15. BTDP - Nearby Thick Disk Stars • About 200 nearby thick disk stars • 2dcoude R 60,000 - S/N~ 300 - 1setup - => 27 elements • Directly comparable to BDP2 • + … HET/HRS data for other 12 more distant thick disk stars

  16. 118 nearest stars brighter than K2V • R ~ 50,000 • S/N>300 • Complete coverage 3700 - 9000 Å 3700-10240 Å • Automatic analysis http://hebe.as.utexas.edu/s4n/archive.html

  17. MISSMultiline Inversion of Stellar Spectra

  18. The Sloan Digital Sky Survey “Simply put, the Sloan Digital Sky Survey is the most ambitious astronomical survey project ever undertaken.” Picture: Fermilab Visual Media Services

  19. Breakdown of the SDSS EDR Sample Candidates • QSO = 1461 • BHB = 1242 • Reddening Std = 714 • Spectrophot Std = 706 • Galaxy = 628 • Other = 853 • TOTAL = 5604 “Other” consists of small numbers of carbon stars, white dwarfs, ROSAT sources, and serendipitous objects

  20. The EDR Spectra • Spectra cover range 3800 Å – 9000 Å, with a large range of S/N ratios (10 < S/N < 50) • Resolving power R = 1800 (e.g., 2.2 Å at 4000 Å) • Spectra are (approximately) flux calibrated • SDSS photometry (u, g, r, i, z) available for all • Although the EDR includes WD, sdB, and cool stars, for the purposes of this work, we concentrate on: • FHB and A stars in range 6000 K < Teff < 10000 K • Main-sequence and giant F, G, and early K in range 4500 K < Teff <6500 K

  21. EDR spectra -- Beta pipeline EDR spectra EDR photometry (u’g’r’i’z’) V mag. = V (ugr) cal. M, R, Mv Distance, Age Spectral Fitting - optimization algorithm Model atmospheres Statistical analysis in HRD -- Stellar evolution models Teff, logg, [M/H] E(B-V) Vr

  22. Automated analysis of spectra • Construction of a grid of synthetic spectra • Use of a grid of pre-calculated grid and filter responses to build a photometric grid • Discreet => Continuum • Optimization algorithm

  23. Optimal Spectral Fits – Examples

  24. Optimal Spectral Fits – Examples

  25. Optimal Spectral Fits – Examples

  26. Optimal Spectral Fits – Examples

  27. EDR spectra -- Beta pipeline EDR spectra EDR photometry (u’g’r’i’z’) V mag. = V (ugr) cal. M, R, Mv Distance, Age Spectral Fitting - optimization algorithm Model atmospheres Statistical analysis in HRD -- Stellar evolution models Teff, logg, [M/H] E(B-V) Vr

  28. EDR -- Basic Properties Galactic coords.

  29. EDR -- Basic Properties Range in V

  30. EDR -- Basic Properties Range in (B-V)

  31. EDR -- Basic Properties Radial Velocities

  32. RAVE - the radial velocity experiment • All-sky survey (complete to V=16) • Vr and abundance ratios for 50,000,000 stars between years 2006-2010 • Piezo-electric ball/spines on a 1m-class telescope observe 20,000 stars/night at R~10,000 • Together with GAIA kinematics and abundances

  33. Summary • Basic elements of galactic structure • Fine structure • Origin and evolution of structural components

  34. Summary • … but a very exciting future ahead …

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