2. Dr. Alan Alves-Brito ARC Super Science Fellow Red giant stars as tracers of the chemical evolution of the Galactic bulge

3. Astounding Stories of Super Science - Hobart, April 18-20.2 Main Collaborators  Dr. Jorge Meléndez (IAG/USP, Brazil)  Prof. Martin Asplund (RSAA, Australia)  Dr. Thomas Bensby (Lund Observatory, Sweden)

4. Astounding Stories of Super Science - Hobart, April 18-20.3 Scientific Motivation  age  kinematics  dynamics  chemical enrichment DIRBE@COBE Dwek et al. 1995 OPTICAL IMAGE Axel Mallenhoff 2001

5. Astounding Stories of Super Science - Hobart, April 18-20.4 Tracers of the Galactic bulge K and M giant stars in the field (e.g. Mcwillian & Rich 1994; Fulbright et al. 2006,2007; Zoccali et al. 2006; Lecureur et al. 2007; Zoccali et al. 2008; Meléndez et al. 2008; Ryde et al. 2009; Alves-Brito et al. 2010; Bensby et al. 2010; Alves-Brito et al. 2012b, in preparation) Giant stars in globular clusters (e.g. Alves-Brito et al. 2006; Barbuy et al. 2006; Barbuy et al. 2009) Dwarf, sub-giant and giant stars in gravitational microlenses (e.g. Cohen et al. 2008;2009; Bensby et al. 2008;2009; Alves-Brito et al. 2012c, in preparation)

6. Astounding Stories of Super Science - Hobart, April 18-20.5 When and how the Galactic bulge was formed? Credit: University of Texas, MacDonald Observatory stellar content (classical) vs. morphology (pseudobulge) Kormendy & Kennicutti 2004 see also Elmegreen et al. 2008

7. Astounding Stories of Super Science - Hobart, April 18-20.6 Main goal: Galactic genealogy Big Bang Fe-peak Light elements Neutron capture Grevesse & Sauval 1998 Solar Abundance Pattern

8. Astounding Stories of Super Science - Hobart, April 18-20.7 Chemical enrichment: [X/Fe] ~ SF [O/Fe] ---> SNII/SNIa Tinsley 1979; Chiappini 2004

9. Astounding Stories of Super Science - Hobart, April 18-20.8 Bulge (giants) vs. Disks (dwarves) The bulge chemical enrichment is dominated by SNII (massive stars). It must have formed faster than both the thick and thin disks Ballero et al. (2007): MDF and [Mg/Fe] imply different IMFs for the bulge and the thick disk. Lecureur et al. 2007 and previous works FLAMES:UVES@VLT: R = 20,000 - 40,000 [Fe/H] = log(Fe/H)_star - log(Fe/H)_sun

10. Astounding Stories of Super Science - Hobart, April 18-20.9 Concerns   Giants (bulge) vs. dwarves (disks): Teff  Zero points on stellar parameters  Line list (different lines, atomic data)  Solar abundances  Methods of analysis

11. Astounding Stories of Super Science - Hobart, April 18-20.10 High resolution spectra PHOENIX@Gemini MIKE@Magellan UVES@VLT ELODIE@OHP 2dcoude@McDonald HIRES@Keck R = /  ≥ 60,000 [Fe/H] = log(Fe/H)_star - log(Fe/H)_sun -1.5 < [Fe/H] < +0.5

12. Astounding Stories of Super Science - Hobart, April 18-20.11 Methods

13. Astounding Stories of Super Science - Hobart, April 18-20.12 Alves-Brito, Meléndez, Asplund et al. 2010, A&A, 513, 35 Meléndez, Asplund, Alves-Brito et al. 2008 : CNO Optical data: R = 60,000 : S/N = 200 thick  thin same knee (thick disk) The bulge and the (local) thick disk are indistinguishable

14. Astounding Stories of Super Science - Hobart, April 18-20.13 Bensby, Alves-Brito, Oye et al. 2010, A&A Bensby, Alves-Brito, Oye et al. 2011, ApJ (outer disk) Optical data: MIKE@Magellan R = 55,000 : S/N = 100 Inner Disk (44 giants : 3-7 kpc)  inner disk,  local thick and thin disks; * bulge The metal poor bulge and the (inner) thick disk are indistinguishable

15. Astounding Stories of Super Science - Hobart, April 18-20.14 Alves-Brito, Johnson, Bensby et al. 2012, in preparation The bulge (normal giants and microlensed ones) and the thick disk are indistinguishable

16. Astounding Stories of Super Science - Hobart, April 18-20.15 Gonzalez, Rejkuba, Zoccali et al. 2011, A&A; also using Alves-Brito et al. 2010’s data Different techniques and independent methods ¡confirm our results! The bulge and the thick disk are indistinguishable Optical data: FLAMES@VLT R = 30,000 : S/N = 100 474 giants in 4 different fields

17. Astounding Stories of Super Science - Hobart, April 18-20.16  Similar chemical evolution: genetic link  Short timescale, similar SFR and IMF  Classical bulge vs. secular/dynamical Bulge vs. local and inner thick-disk: Conclusions

18. Astounding Stories of Super Science - Hobart, April 18-20.17  What about the heavy elements?  Bulge vs Thin/Thick disk in the Galactic center  The critical -0.3 < [Fe/H] < +0.0 range  Gaia mission (from 2011-2020): ~1 billion of stars to V=20. 3D map of our Galaxy  Australian GMT, HERMES  SIMPLE@E-Extremely Large Telescopes: high R of dwarf stars in the bulge! More info: bulge vs. inner disks Age spread, kinematics and chemical abundances can constrain different models of bulge formation Perspectives

19. Astounding Stories of Super Science - Hobart, April 18-20.18 Thank you very much

20. Astounding Stories of Super Science - Hobart, April 18-20.19 Bulge MDF

21. Astounding Stories of Super Science - Hobart, April 18-20.20 ~245,000 stars l,b = 1 0.25,-2 0.65 CMD @HST t = 10Gyr ([Fe/H] = 0) Unevolved MS t = 10Gyr ([Fe/H] =0.5) t = GC +- 2.5 Gyr (Ortolani et al. 1995; Zoccali et al. 2003) Sahu et al. 2006

22. Astounding Stories of Super Science - Hobart, April 18-20.21 # 19 gigantes do bojo + 49 gigantes de comparação Meléndez, Asplund, Alves-Brito et al. 2008, A&A : IR: Phoenix@Gemini-S bulge thick disk thin disk halo [O/Fe] vs. [Fe/H] [(C+N)/Fe] vs. [Fe/H] [(C+N)/Fe] = cte [O/Fe] = 0.41 - 0.02*[Fe/H] [O/Fe] = 0.39 - 0.01*[Fe/H]  [O/Fe] = 0.03  0.09 dex The bulge and the (local) thick disk are indistinguishable

23. Astounding Stories of Super Science - Hobart, April 18-20.22 # 11 giants in the bulge X Meléndez et al. 2008 Ryde, Gustafson, Edvardson et al. 2009, A&A IR: CRIRES@VLT : CNO, R = 70,000 : S/N = 40-110 [O/Fe] @ IR : Phoenix and CRIRES results are consistent

24. Astounding Stories of Super Science - Hobart, April 18-20.23 Thick disk formation Michelle et al. 2011  Accretion  Heating via a minor merger  Intense SF in a gas turbulent environment  Radial migration

25. Astounding Stories of Super Science - Hobart, April 18-20.24 Ages of Disk Stars Thick disk: ~10 Gyr Thin disk: <8 Gyr Bensby et al. (2007)

26. Astounding Stories of Super Science - Hobart, April 18-20.25 Inner disk stars

27. Astounding Stories of Super Science - Hobart, April 18-20.26 Inner disk: Toomre Diagram Bensby et al. (2010)

28. Astounding Stories of Super Science - Hobart, April 18-20.27 Uncertainties ∆T = ±100K : ∆logg = ±0.30 dex : ∆v = ±0.20 Km/s Fe: 0.03 dex Mg: 0.07 dex C: 0.11 dex Si: 0.12 dex N: 0.11 dex Ca: 0.10 dex O: 0.14 dex Ti: 0.17 dex

29. Astounding Stories of Super Science - Hobart, April 18-20.28 Uncertainties  Continuum level  Line fitting (?)  Damping parameters  Stellar atmospheres : 1D models  Non-LTE effects