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Gas accretion as the origin of chemical abundance gradients in distant galaxies

Abstract

It has recently been suggested1,2 that galaxies in the early Universe could have grown through the accretion of cold gas, and that this may have been the main driver of star formation and stellar mass growth3,4,5. Because the cold gas is essentially primordial, it has a very low abundance of elements heavier than helium (referred to as metallicity). If funnelled to the centre of a galaxy, it will result in the central gas having an overall lower metallicity than gas further from the centre, because the gas further out has been enriched by supernovae and stellar winds, and not diluted by the primordial gas. Here we report chemical abundances across three rotationally supported star-forming galaxies at redshift z ≈ 3, only 2 Gyr after the Big Bang. We find ‘inverse’ gradients, with the central, star-forming regions having lower metallicities than less active ones, which is opposite to what is seen in local galaxies6,7. We conclude that the central gas has been diluted by the accretion of primordial gas, as predicted by ‘cold flow’ models.

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Figure 1: Surface brightness and velocity of the [O  iii ] 5,007 Å line, and metallicity maps.
Figure 2: Gas fractions for the different regions in the observed galaxies.

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References

  1. Dekel, A. et al. Cold streams in early massive hot haloes as the main mode of galaxy formation. Nature 457, 451–454 (2009)

    Article  ADS  CAS  Google Scholar 

  2. Bournaud, F. & Elmegreen, B. G. Unstable disks at high redshift: evidence for smooth accretion in galaxy formation. Astrophys. J. 694, L158–L161 (2009)

    Article  ADS  Google Scholar 

  3. Förster Schreiber, N. M. et al. The SINS survey: SINFONI integral field spectroscopy of z 2 star-forming galaxies. Astrophys. J. 706, 1364–1428 (2009)

    Article  ADS  Google Scholar 

  4. Daddi, E. et al. Multiwavelength study of massive galaxies at z 2. I. Star formation and galaxy growth. Astrophys. J. 670, 156–172 (2007)

    Article  ADS  CAS  Google Scholar 

  5. Tacconi, L. J. et al. High molecular gas fractions in normal massive star forming galaxies in the young Universe. Nature 463, 781–784 (2010)

    Article  ADS  CAS  Google Scholar 

  6. Garnett, D. R., Shields, G. A., Skillman, E. D., Sagan, S. P. & Dufour, R. J. Interstellar abundance gradients in NGC 2403: comparison to M33. Astrophys. J. 489, 63–86 (1997)

    Article  ADS  CAS  Google Scholar 

  7. Magrini, L., Sestito, P., Randich, S. & Galli, D. The evolution of the Galactic metallicity gradient from high-resolution spectroscopy of open clusters. Astron. Astrophys. 494, 95–108 (2009)

    Article  ADS  CAS  Google Scholar 

  8. Steidel, C. C. et al. Lyman break Galaxies at redshift z 3: survey description and full data set. Astrophys. J. 592, 728–754 (2003)

    Article  ADS  Google Scholar 

  9. Maiolino, R. et al. AMAZE. I. The evolution of the mass-metallicity relation at z > 3. Astron. Astrophys. 488, 463–479 (2008)

    Article  ADS  Google Scholar 

  10. Mannucci, F. et al. LSD: Lyman-break galaxies stellar populations and dynamics – I. Mass, metallicity and gas at z 3.1. Mon. Not. R. Astron. Soc. 398, 1915–1931 (2009)

    Article  ADS  CAS  Google Scholar 

  11. Pozzetti, L. et al. The VIMOS VLT deep survey. The assembly history of the stellar mass in galaxies: from the young to the old universe. Astron. Astrophys. 474, 443–459 (2007)

    Article  ADS  CAS  Google Scholar 

  12. Hopkins, A. M. & Beacom, J. F. On the normalization of the cosmic star formation history. Astrophys. J. 651, 142–154 (2006)

    Article  ADS  CAS  Google Scholar 

  13. Kennicutt, R. C., Jr Star formation in galaxies along the Hubble sequence. Annu. Rev. Astron. Astrophys. 36, 189–231 (1998)

    Article  ADS  CAS  Google Scholar 

  14. Eisenhauer, F. et al. SINFONI – Integral field spectroscopy at 50 milli-arcsecond resolution with the ESO VLT. Proc. SPIE 4841, 1548–1561 (2003)

    Article  ADS  Google Scholar 

  15. Nagao, T., Maiolino, R. & Marconi, A. Gas metallicity diagnostics in star-forming galaxies. Astron. Astrophys. 459, 85–101 (2006)

    Article  ADS  CAS  Google Scholar 

  16. van Zee, L., Salzer, J. J., Haynes, M. P., O'Donoghue, A. A. & Balonek, T. J. Spectroscopy of outlying H II regions in spiral galaxies: abundances and radial gradients. Astron. J. 116, 2805–2833 (1998)

    Article  ADS  CAS  Google Scholar 

  17. Dopita, M. A. et al. Modeling the pan-spectral energy distribution of starburst galaxies. III. Emission line diagnostics of ensembles of evolving H II regions . Astrophys. J. 167 (Suppl.). 177–200 (2006)

    Article  CAS  Google Scholar 

  18. Levesque, E. M., Kewley, L. J. & Larson, K. L. Theoretical modeling of star-forming galaxies. I. Emission-line diagnostic grids for local and low-metallicity galaxies. Astron. J. 139, 712–727 (2010)

    Article  ADS  CAS  Google Scholar 

  19. Martín-Manjón, M. L., García-Vargas, M. L., Mollá, M. & Díaz, A. I. POPSTAR evolutionary synthesis models. II: optical emission-line spectra from giant HII regions. Mon. Not. R. Astron. Soc. 403, 2012–2032 (2010)

    Article  ADS  Google Scholar 

  20. Molla, M., Ferrini, F. & Diaz, A. I. Evolution of spiral galaxies. VII. Time evolution of the radial distributions of abundances. Astrophys. J. 475, 519–533 (1997)

    Article  ADS  Google Scholar 

  21. Hou, J. L., Prantzos, N. & Boissier, S. Abundance gradients and their evolution in the Milky Way disk. Astron. Astrophys. 362, 921–936 (2000)

    ADS  CAS  Google Scholar 

  22. Tinsley, B. M. Stellar lifetimes and abundance ratios in chemical evolution. Astrophys. J. 229, 1046–1056 (1979)

    Article  ADS  CAS  Google Scholar 

  23. Kereš, D., Katz, N., Weinberg, D. H. & Davé, R. How do galaxies get their gas? Mon. Not. R. Astron. Soc. 363, 2–28 (2005)

    Article  ADS  Google Scholar 

  24. Cresci, G. et al. The SINS survey: modeling the dynamics of z 2 galaxies and the high-z Tully-Fisher relation. Astrophys. J. 697, 115–132 (2009)

    Article  ADS  CAS  Google Scholar 

  25. Genzel, R. et al. From rings to bulges: evidence for rapid secular galaxy evolution at z 2 from integral field spectroscopy in the SINS survey. Astrophys. J. 687, 59–77 (2008)

    Article  ADS  CAS  Google Scholar 

  26. Kennicutt, R. C., Jr The global Schmidt law in star-forming galaxies Astrophys . J. 498, 541–552 (1998)

    ADS  CAS  Google Scholar 

  27. Bouché, N. et al. Dynamical properties of z 2 star-forming galaxies and a universal star formation relation. Astrophys. J. 671, 303–309 (2007)

    Article  ADS  Google Scholar 

  28. Erb, D. K. A model for star formation, gas flows, and chemical evolution in galaxies at high redshifts. Astrophys. J. 674, 151–156 (2008)

    Article  ADS  CAS  Google Scholar 

  29. Mannucci, F., Cresci, G., Maiolino, R., Marconi, A. & Gnerucci, A. A fundamental relation between mass, SFR and metallicity in local and high redshift galaxies. Mon. Not. R. Astron. Soc. . (in the press); preprint at 〈http://arXiv.org/abs/1005.0006〉 (2010)

  30. Chabrier, G. Galactic stellar and substellar initial mass function. Publ. Astron. Soc. Pacif. 115, 763–795 (2003)

    Article  ADS  Google Scholar 

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Acknowledgements

SINFONI data were obtained from observations made with the ESO Telescopes at the Paranal Observatories. We thank the ESO staff for their work and support. This work was supported by INAF and ASI.

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All authors have contributed extensively to data reduction and interpretation.

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Correspondence to G. Cresci.

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The authors declare no competing financial interests.

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The file contains Supplementary Information (measuring metallicities), additional references and Supplementary Figures 1-3 with legends. (PDF 963 kb)

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Cresci, G., Mannucci, F., Maiolino, R. et al. Gas accretion as the origin of chemical abundance gradients in distant galaxies. Nature 467, 811–813 (2010). https://doi.org/10.1038/nature09451

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