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Chemical evolution of the Galaxy disk in connection with large-scale winds

Published online by Cambridge University Press:  01 June 2008

Takuji Tsujimoto
Affiliation:
National Astronomical Observatory, Mitaka-shi, Tokyo 181-8588, Japan email: taku.tsujimoto@nao.ac.jp
Joss Bland-Hawthorn
Affiliation:
Institute of Astronomy, School of Physics, University of Sydney, NSW 2006, Australia
Kenneth C. Freeman
Affiliation:
Research School of Astronomy and Astrophysics (RSAA), Australian National University, Cotter Road, Weston Creek, ACT 2611, Australia
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Abstract

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Comparison of elemental abundance features between old and young thin disk stars may reveal the action of ravaging winds from the Galactic bulge, which once enriched the whole disk, and set up the steep abundance gradient in the inner disk (RGC ≲ 10–;12 kpc) and simultaneously the metallicity floor ([Fe/H]~ −0.5) in the outer disk. After the end of a crucial influence by winds, chemical enrichment through accretion of a metal-poor material from the halo onto the disk gradually reduced the metallicity of the inner region, whereas an increase in the metallicity proceeded beyond a solar circle. This results in a flattening of abundance gradient in the inner disk, and our chemical evolution models confirm this mechanism for a flattening, which is in good agreement with the observations. Our scenario also naturally explains an observed break in the metallicity floor of the outer disk by young stars since the limit of self-enrichment in the outer disk is supposed to be [Fe/H]≲ −1 and inevitably incurs a direct influence of the dilution by a low-metal infall whose metallicity is [Fe/H]~ −1. Accordingly, we propose that the enrichment by large-scale winds is a crucial factor for chemical evolution of the disk, and claim to reconsider the models thus far for the disk including the solar neighborhood, in which the metallicity is predicted to monotonously increase with time. Furthermore, we anticipate that a flattening of abundance gradient together with a metal-rich floor in the outer disk are the hallmark of disk galaxies with significant central bulges.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2009

References

Andrievsky, S. M., Luck, R. E., Martin, P., & Lépine, J.R.D. 2004, A&A, 413, 159Google Scholar
Bensby, T., Feltzing, S., Lundström, I., & Ilyiin, I. 2005, A&A, 433, 185Google Scholar
Benson, A. J., Džanović, D., Frenk, C. S., & Sharples, R. 2007, MNRAS, 379, 841Google Scholar
Sellwood, J. A. & Binney, J. J. 2002, MNRAS, 336, 785Google Scholar
Bland-Hawthorn, J. & Cohen, M. 2003, ApJ, 582, 246Google Scholar
Boissier, S. & Prantzos, N. 1999, MNRAS, 307, 857Google Scholar
Carney, B. W., Yong, D., de Almeida, L., & Seitzer, P. 2005, AJ, 130, 1111Google Scholar
Cen, R. & Ostriker, J. P. 1999, ApJ, 514, 1Google Scholar
Chiappini, C., Matteucci, F., & Romano, D. 2001, ApJ, 554, 1044Google Scholar
Cunha, K., Smith, V. V., & Lambert, D. L. 1998, ApJ, 493, 195Google Scholar
Daflon, S. & Cunha, K. 2004, ApJ, 617, 1115Google Scholar
Dalcanton, J. J. 2007, ApJ, 658, 941Google Scholar
Davé, R., Oppenheimer, B. D., & Sivanandam, S. 2008, submitted to MNRASGoogle Scholar
Driver, S. P., Allen, P. D., Liske, J., & Graham, A. W. 2007, ApJ, 657, L85Google Scholar
Edvardsson, B. et al. 1993, A&A, 275, 101Google Scholar
Everett, J. E. et al. 2008, ApJ, 674, 258Google Scholar
Fall, S. M. 2006, in: Athanassoula, E., Bosma, A., & Mujica, R. (eds.) Disks of Galaxies: Kinematics, Dynamics and Perturbations (San Francisco: ASP), p. 389Google Scholar
Feltzing, S. & Gustafsson, B. 1998, A&AS, 129, 237Google Scholar
Friel, E. D. 2006, in: Pasquini, L. & Randich, S. (eds.) Chemical Abundances and Mixing in Stars in the Milky Way and its Satellites (Berlin: Springer), p. 3Google Scholar
Fox, A. J. et al. 2005, ApJ, 630, 332Google Scholar
Gouda, N. et al. 2008, in: Jin, W.-J., Platais, I., & Perryman, M. (eds.), A Giant Step: from Milli- to Micro-arcsecond Astrometry, Proc. IAU Symp. No. 248 (San Francisco: ASP), p. 248Google Scholar
Hou, J. L., Prantzos, N., & Boissier, S. 2000, A&A, 362, 921Google Scholar
Keeney, B. A. et al. 2006, ApJ, 646, 951Google Scholar
Lemasle, B. et al. 2007, A&A, 467, 283Google Scholar
Maciel, W. L., Lago, L. G., & Costa, R. D. D. 2006, A&A, 453, 587Google Scholar
Madau, P., Ferrara, A., & Rees, M.J. 2001, ApJ, 555, 92Google Scholar
Matteucci, F. & François, P. 1989, MNRAS, 239, 885Google Scholar
Navarro, J. F. & White, S. D. M. 1994, MNRAS, 267, 401Google Scholar
Navarro, J. F., Frenk, C. S., & White, S. D. M. 1995, MNRAS, 275, 56CrossRefGoogle Scholar
Reid, I. N., Turner, E. L., Turnbull, M. C., Mountain, M., & Valenti, J. A. 2007, ApJ, 665, 767Google Scholar
Ruffle, P. M. E. et al. 2007, ApJ, 671, 1766Google Scholar
Ryan-Weber, E. V., Pettini, M., & Madau, P. 2006, MNRAS, 371, L78Google Scholar
Simón-Díaz, S. 2006, astro-ph/0611513Google Scholar
Steinmetz, M. & Müller, E. 1995, MNRAS, 276, 549Google Scholar
Tremonti, C. A. et al. 2004, ApJ, 613, 898Google Scholar
Tsujimoto, T. 2007, ApJ, 665, L115Google Scholar
Veilleux, S., Cecil, G., & Bland-Hawthorn, J. 2005, ARA&A, 43, 769Google Scholar
Wyse, R. F. G. & Gilmore, G. 1995, AJ, 110, 2771Google Scholar
Yasui, C., Kobayashi, N., Tokunaga, A. T., Terada, H., & Saito, M. 2008, ApJ, 675, 443Google Scholar
Yong, D., Carney, B. W., & de Almeida, L. 2005, AJ, 130, 597Google Scholar
Yong, D., Carney, B. W., Luísa, M., de Almeida, L., & Pohl, B. L. 2006, AJ, 131, 2256Google Scholar