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C. Morossi , M . Franchini , P . Di Marcantonio

Chemical evolution in the Universe: the next 30 years 16-20 Sept , 2013 Castiglione della Pescaia, Italy. Lick/SDSS library v2.0: a new tool to compute model of stellar populations with variable Alpha element abundance ratios. C. Morossi , M . Franchini , P . Di Marcantonio

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C. Morossi , M . Franchini , P . Di Marcantonio

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  1. Chemical evolution in the Universe: the next 30 years 16-20 Sept, 2013 Castiglione della Pescaia, Italy Lick/SDSS library v2.0: a new tool to compute model of stellar populations with variable Alpha element abundance ratios C. Morossi, M. Franchini, P. Di Marcantonio INAF-OsservatorioAstronomico Trieste, Italy M.L. Malagnini Dip. Fisica, Univ. Trieste, Italy &INAF M.Chavez INAOE, Mexico

  2. Lick/SDSS SpectralIndices

  3. Lick/SDSSlibrary v1.0 (Franchini et al. 2010) Computed starting from synthetic spectra degraded at R=1800 (like SDSS) • Two grids of HiRes synthetic spectra: Solar Scaled [ /Fe] = +0.0 (SSA) and -enhanced [ /Fe] = +0.4 (NSSA) • starting from Kurucz atmosphere models (ATLAS9) computed with solar and -enhancedODF’s by Castelli (2003) • using SPECTRUM V.2.75 (Gray and Corbally 1994) There is full consistency between synthetic spectra and the ODF of the atmosphere models Teff : 3500-7000 K (250 K step) log g: 0.5- 5.0 dex (0.5 dex step) [Fe/H]=-2.5,-2.0,-1.5,-1.0,-0.5, [Fe/H]=-2.5,-2.0,-1.5,-1.0,-0.5,0.0,+0.2,+0.5 (NSSA) [Fe/H]=-2.5,-2.0,-1.5,-1.0,-0.5,0.0,+0.2,+0.5 (SSA).0,+0.2,+0.5 (SSA) [Fe/H]=-2.5,-2.0,-1.5,-1.0,-0.5,0.0,+0.2,+0.5 (NSSA)

  4. Stellar atmospheric parameters FromLick/SDSS library v1.0we (Franchini et al. ApJ 2011, 730, 117) derived the atmospheric parameters of more than 4000 F, G, and K SDSS stars by comparing synthetic and observed spectral indices • Indices are negligibly affected by errors in flux calibration and by reddening • Narrow-band indices allow the measurement of the intensity of features of different chemical species separately • Indices are characterized by higher S/N than the original spectra • Homogeneous and self-consistent atmospheric parameter estimates BUT ...

  5. Lick/SDSSlibraryv1.0 mainlimitations • Only 2 values of [ /Fe] • All  element abundances varying in “lock steps” • Matching with observed values via ad-hoc calibration

  6. Is [ /Fe] the same for all the elements? The [Mg/Fe] and [Ca/Fe] derived for more than 4000 F, G, and K SDSS-DR7 stars by means of Lick/SDSSlibrary v1.0 are different !

  7. Lick/SDSSlibrary v2.0 (in preparation) • Kurucz atmosphere models computed with ATLAS12 • Refined and more complete atomic and molecular line list • HiRessynthetic spectra computed with SPECTRUM V.2.76e (Gray and Corbally 1994) • several chemical compositions: Solar Scaled with [Fe/H] from +0.5 to -3.0 with Δ[Fe/H]=0.25 (SSA) -enhanced with [ /Fe] from +1.0 to -1.5 with Δ[α/Fe]=0.25 (NSSA) Individual -element enhanced (i.e. Mg, Si, Ca, Ti) • full consistency between synthetic spectra and atmosphere models • No need of ad-hoc calibration for most of the synthetic indices )

  8. Are the new synthetic indices more reliable? Comparison with the observed ones requires: • Good observations • Accurate estimates of atmospheric stellar parameters

  9. Goodobservations • The UVES ParanalObservatory Project: A Library of High- ResolutionSpectra of Stars across the Hertzsprung-Russell Diagram(2003) Bagnulo, S.; Jehin, E.; Ledoux, C.; Cabanac, R.; Melo, C.; Gilmozzi, R The Messenger (ISSN0722-6691), No.114, p. 10-14 • The ELODIE Archive (2004) Moultaka, J.; Ilovaisky, S. A.; Prugniel, P.; Soubiran, C. The Publications of the Astronomical Society of the Pacific, Volume 116, Issue 821, pp. 693 • The Indo-US Library of CoudéFeed Stellar Spectra (2004) Valdes, Francisco; Gupta, Ranjan; Rose, James A.; Singh, Harinder P.; Bell, David J. The Astrophysical Journal Supplement Series, Volume 152, Issue 2, pp. 251-259. • Medium-resolution Isaac Newton Telescopelibrary of empiricalspectra - II. The stellar atmosphericparameters . (2007) Cenarro, A. J.; Peletier, R. F.; Sánchez-Blázquez, P.; Selam, S. O.; Toloba, E.; Cardiel, N.; Falcón-Barroso, J.; Gorgas, J.; Jiménez-Vicente, J.; Vazdekis, A MonthlyNotices of the RoyalAstronomical Society, Volume 374, Issue 2, pp. 664-690

  10. Accurate estimates of atmospheric stellar parameters (1) The Chemical Evolution of the Galactic Disk - Part One - Analysis and Results Edvardsson, B.; Andersen, J.; Gustafsson, B.; Lambert, D. L.; Nissen, P. E.; Tomkin, J. < .AstronAstrophys., 275, 101 (1993)> Abundances and Kinematics of Field Halo and Disk Stars I: Observational Data and Abundance Analysis Fulbright J.P. . <Astron. J. 120, 1841 (2000)> The chemical compositions of Galactic disc F and G dwarfs Reddy, Bacham E.; Tomkin, Jocelyn; Lambert, David L.; Allende Prieto, Carlos <M.N.R.A.S., 340, 304 (2003)> Stellar chemical signatures and hierarchical galaxy formation. Venn K.A., Irwin M., Shetrone M.D., Tout C.A., Hill V., Tolstoy E. <Astron. J., 128, 1177-1195 (2004)> Alpha-, r-, and s-process element abundance trends in the Galactic thin and thick disks T. Bensby, S. Feltzing, I. Lundstrom, and I. Ilyin <Astron. Astrophys. 433l, 185 (2005)> Giants in the local region. Luck R.E., Heiter U. <Astron. J., 133, 2464-2486 (2007)> Photospheric CNO abundances of solar-type stars. Takeda Y., Honda S. <Publ. Astron. Soc. Jap., 57, 65-82 (2005)> Fundamental parameters and elemental abundances of 160 F-G-K stars based on OAO spectrum database. Takeda Y. <Publ. Astron. Soc. Jap., 59, 335-356 (2007)> A holistic approach to carbon-enhanced metal-poor stars. Masseron T., Johnson J.A., Plez B., Van Eck S., Primas F., Goriely S., Jorissen A. <Astron. Astrophys., 509, A93 (2010)> Homogeneous photospheric parameters and C abundances in G and K nearby stars with and without planets. Da Silva R., Milone A., Reddy B.E. <Astron. Astrophys. 526, A71 (2011)> …

  11. Accurate estimates of atmospheric stellar parameters (2) The comparison of our results with published high-resolution analysis results shows that some of the latter may be affected by systematic errors and/or a lack of self-consistency.

  12. Accurate and complete atomic and molecular line list (1)

  13. Accurate and complete atomic and molecular line list (22) • Individual element abundancies • Self-consistent models and spectra • Empirical log gf’s • Different microturbulence velocity for giants and dwarfs

  14. Preliminary results based on 222 “bona-fide” stars (1)

  15. Preliminary results based on 222 “bona-fide” stars (2)

  16. Chemical evolution in the Universe: the next 30 years 16-20 Sept, 2013 Castiglione della Pescaia, Italy Thank you

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