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A common mass scale for satellite galaxies of the Milky Way

Nature volume 454, pages 1096–1097 (2008)Cite this article

Abstract

The Milky Way has at least twenty-three known satellite galaxies that shine with luminosities ranging from about a thousand to a billion times that of the Sun. Half of these galaxies were discovered1,2 in the past few years in the Sloan Digital Sky Survey, and they are among the least luminous galaxies in the known Universe. A determination of the mass of these galaxies provides a test of galaxy formation at the smallest scales3,4 and probes the nature of the dark matter that dominates the mass density of the Universe5. Here we use new measurements of the velocities of the stars in these galaxies6,7 to show that they are consistent with them having a common mass of about 107 within their central 300 parsecs. This result demonstrates that the faintest of the Milky Way satellites are the most dark-matter-dominated galaxies known, and could be a hint of a new scale in galaxy formation or a characteristic scale for the clustering of dark matter.

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Figure 1: The integrated mass of the Milky Way dwarf satellites, in units of solar masses, within their inner 0.3 kpc as a function of their total luminosity, in units of solar luminosities.

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References

  1. Willman, B. et al. A new Milky Way companion: unusual globular cluster or extreme dwarf satellite? Astron. J. 129, 2692–2700 (2005)

    Article  ADS  Google Scholar 

  2. Belokurov, V. et al. Cats and dogs, hair and a hero: a quintet of new Milky Way companions. Astrophys. J. 654, 897–906 (2007)

    Article  ADS  Google Scholar 

  3. Mateo, M. L. Dwarf galaxies of the Local Group. Annu. Rev. Astron. Astrophys. 36, 435–506 (1998)

    Article  ADS  CAS  Google Scholar 

  4. Gilmore, G. et al. The observed properties of dark matter on small spatial scales. Astrophys. J. 663, 948–959 (2007)

    Article  ADS  Google Scholar 

  5. Spergel, D. N. et al. Three-year Wilkinson Microwave Anisotropy Probe (WMAP) observations: implications for cosmology. Astrophys. J. 170, S377–S408 (2007)

    Article  ADS  Google Scholar 

  6. Simon, J. D. & Geha, M. The kinematics of the ultra-faint Milky Way satellites: solving the missing satellite problem. Astrophys. J. 670, 313–331 (2007)

    Article  ADS  CAS  Google Scholar 

  7. Walker, M. G. et al. Velocity dispersion profiles of seven dwarf spheroidal galaxies. Astrophys. J. 667, L53–L56 (2007)

    Article  ADS  Google Scholar 

  8. Peebles, P. J. E. Large-scale background temperature and mass fluctuations due to scale invariant primeval perturbations. Astrophys. J. 263, L1–L5 (1982)

    Article  ADS  CAS  Google Scholar 

  9. White, S. D. M., Frenk, C. S. & Davis, M. Clustering in a neutrino-dominated universe. Astrophys. J. 274, L1–L5 (1983)

    Article  ADS  CAS  Google Scholar 

  10. Blumenthal, G. R., Faber, S. M., Primack, J. R. & Rees, M. J. Formation of galaxies and large-scale structure with cold dark matter. Nature 311, 517–525 (1984)

    Article  ADS  CAS  Google Scholar 

  11. Klypin, A., Kravtsov, A. V., Valenzuela, O. & Prada, F. Where are the missing galactic satellites? Astrophys. J. 522, 82–92 (1999)

    Article  ADS  CAS  Google Scholar 

  12. Moore, B. et al. Dark matter substructure within galactic halos. Astrophys. J. 524, L19–L22 (1999)

    Article  ADS  CAS  Google Scholar 

  13. Diemand, J., Moore, B. & Stadel, J. Earth-mass dark matter haloes as the first structures in the early Universe. Nature 433, 389–391 (2005)

    Article  ADS  CAS  Google Scholar 

  14. Diemand, J., Kuhlen, M. & Madau, P. Dark matter substructure and gamma-ray annihilation in the Milky Way halo. Astrophys. J. 657, 262–270 (2007)

    Article  ADS  Google Scholar 

  15. Bode, P., Ostriker, J. P. & Turok, N. Halo formation in warm dark matter models. Astrophys. J. 556, 93–107 (2001)

    Article  ADS  CAS  Google Scholar 

  16. Efstathiou, G. Suppressing the formation of dwarf galaxies via photoionization. Mon. Not. R. Astron. Soc. 256, 43P–47P (1992)

    Article  ADS  Google Scholar 

  17. Kauffmann, G., White, S. D. M. & Guiderdoni, B. The formation and evolution of galaxies within merging dark matter haloes. Mon. Not. R. Astron. Soc. 264, 201–218 (1993)

    Article  ADS  CAS  Google Scholar 

  18. Bullock, J. S., Kravtsov, A. V. & Weinberg, D. H. Reionization and the abundance of galactic satellites. Astrophys. J. 539, 517–521 (2000)

    Article  ADS  Google Scholar 

  19. Kravtsov, A. V., Gnedin, O. Y. & Klypin, A. A. The tumultuous lives of galactic dwarfs and the missing satellites problem. Astrophys. J. 609, 482–497 (2004)

    Article  ADS  CAS  Google Scholar 

  20. Mayer, L., Kazantzidis, S., Mastropietro, C. & Wadsley, J. Early gas stripping as the origin of the darkest galaxies in the Universe. Nature 445, 738–740 (2007)

    Article  ADS  CAS  Google Scholar 

  21. Muñoz, R. R. et al. Exploring halo substructure with giant stars: the dynamics and metallicity of the dwarf spheroidal in Boötes. Astrophys. J. 650, L51–L54 (2006)

    Article  ADS  Google Scholar 

  22. Martin, N. F., Ibata, R. A., Chapman, S. C., Irwin, M. & Lewis, G. F. A. Keck/DEIMOS spectroscopic survey of faint Galactic satellites: searching for the least massive dwarf galaxies. Mon. Not. R. Astron. Soc. 380, 281–300 (2007)

    Article  ADS  CAS  Google Scholar 

  23. Strigari, L. E. et al. Redefining the missing satellites problem. Astrophys. J. 669, 676–683 (2007)

    Article  ADS  Google Scholar 

  24. Mateo, M., Olszewski, E. W., Pryor, C., Welch, D. L. & Fischer, P. The Carina dwarf spheroidal galaxy: How dark is it? Astron. J. 105, 510–526 (1993)

    Article  ADS  Google Scholar 

  25. Piatek, S. & Pryor, C. The effect of galactic tides on the apparent mass-to-light ratios in dwarf spheroidal galaxies. Astron. J. 109, 1071–1085 (1995)

    Article  ADS  Google Scholar 

  26. Fellhauer, M. et al. Is Ursa Major II the progenitor of the orphan stream? Mon. Not. R. Astron. Soc. 375, 1171–1179 (2007)

    Article  ADS  Google Scholar 

  27. Dunkley, J. et al. Five-year Wilkinson Microwave Anisotropy Probe (WMAP) observations: likelihoods and parameters from the WMAP data. Preprint available at 〈http://arxiv.org/abs/0803.0586〉 (2008)

  28. Bullock, J. S. et al. Profiles of dark haloes: evolution, scatter and environment. Mon. Not. R. Astron. Soc. 321, 559–575 (2001)

    Article  ADS  Google Scholar 

  29. Dekel, A. & Silk, J. The origin of dwarf galaxies, cold dark matter, and biased galaxy formation. Astrophys. J. 303, 39–55 (1986)

    Article  ADS  CAS  Google Scholar 

  30. Wyithe, J. S. B. & Loeb, A. Suppression of dwarf galaxy formation by cosmic reionization. Nature 441, 322–324 (2006)

    Article  ADS  CAS  Google Scholar 

  31. Martin, N. F., de Jong, J. T. A. & Rix, H.-W. A comprehensive maximum likelihood analysis of the structural properties of faint Milky Way satellites. Preprint at 〈http://arxiv.org/abs/0805.2945〉 (2008)

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Acknowledgements

We thank K. Johnston and S. White for discussion on this paper, and J. Strader for help in the acquisition of data for the Willman 1 satellite.

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Authors and Affiliations

  1. Department of Physics and Astronomy, Center for Cosmology, University of California, Irvine, California 92697-4574, USA,

    Louis E. Strigari, James S. Bullock & Manoj Kaplinghat

  2. Department of Astronomy, California Institute of Technology, 1200 East California Boulevard, MS105-24, Pasadena, California 91125, USA,

    Joshua D. Simon

  3. Department of Astronomy, Yale University, PO Box 208101, New Haven, Connecticut 06520-8101, USA,

    Marla Geha

  4. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138, USA ,

    Beth Willman

  5. Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK ,

    Matthew G. Walker

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  1. Louis E. Strigari
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  7. Matthew G. Walker
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Correspondence to Louis E. Strigari.

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The file contains Supplementary Discussion with additional references, Supplementary Table 1 and Supplementary Figures 1-2 with Legends. (PDF 487 kb)

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Strigari, L., Bullock, J., Kaplinghat, M. et al. A common mass scale for satellite galaxies of the Milky Way. Nature 454, 1096–1097 (2008). https://doi.org/10.1038/nature07222

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