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Velocity anti-correlation of diametrically opposed galaxy satellites in the low-redshift Universe


Recent work has shown that the Milky Way and the Andromeda galaxies both possess the unexpected property that their dwarf satellite galaxies are aligned in thin and kinematically coherent planar structures1,2,3,4,5,6,7. It is interesting to evaluate the incidence of such planar structures in the larger galactic population, because the Local Group may not be a representative environment. Here we report measurements of the velocities of pairs of diametrically opposed satellite galaxies. In the local Universe (redshift z < 0.05), we find that satellite pairs out to a distance of 150 kiloparsecs from the galactic centre are preferentially anti-correlated in their velocities (99.994 per cent confidence level), and that the distribution of galaxies in the larger-scale environment (out to distances of about 2 megaparsecs) is strongly clumped along the axis joining the inner satellite pair (>7σ confidence). This may indicate that planes of co-rotating satellites, similar to those seen around the Andromeda galaxy, are ubiquitous, and their coherent motion suggests that they represent a substantial repository of angular momentum on scales of about 100 kiloparsecs.

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Figure 1: Satellite correlation test.
Figure 2: Anti-correlated satellites in the SDSS.
Figure 3: Correlation with environment.


  1. Kroupa, P., Theis, C. & Boily, C. M. The great disk of Milky-Way satellites and cosmological sub-structures. Astron. Astrophys. 431, 517–521 (2005)

    ADS  Article  Google Scholar 

  2. Pawlowski, M. S., Pflamm-Altenburg, J. & Kroupa, P. The VPOS: a vast polar structure of satellite galaxies, globular clusters and streams around the Milky Way. Mon. Not. R. Astron. Soc. 423, 1109–1126 (2012)

    ADS  Article  Google Scholar 

  3. Pawlowski, M. S., Kroupa, P. & Jerjen, H. Dwarf galaxy planes: the discovery of symmetric structures in the Local Group. Mon. Not. R. Astron. Soc. 435, 1928–1957 (2013)

    ADS  Article  Google Scholar 

  4. Pawlowski, M. S. & Kroupa, P. The rotationally stabilized VPOS and predicted proper motions of the Milky Way satellite galaxies. Mon. Not. R. Astron. Soc. 435, 2116–2131 (2013)

    ADS  Article  Google Scholar 

  5. Ibata, R. A. et al. A vast, thin plane of corotating dwarf galaxies orbiting the Andromeda galaxy. Nature 493, 62–65 (2013)

    ADS  Article  Google Scholar 

  6. Conn, A. R. et al. The three-dimensional structure of the M31 satellite system; strong evidence for an inhomogeneous distribution of satellites. Astrophys. J. 766, 120 (2013)

    ADS  Article  Google Scholar 

  7. Ibata, R. A. et al. A thousand shadows of Andromeda: rotating planes of satellites in the Millennium-II cosmological simulation. Astrophys. J. 784, L6 (2014)

    ADS  Article  Google Scholar 

  8. Lynden-Bell, D. Dwarf galaxies and globular clusters in high velocity hydrogen streams. Mon. Not. R. Astron. Soc. 174, 695–710 (1976)

    CAS  ADS  Article  Google Scholar 

  9. Adelman-McCarthy, J. K. et al. The fourth data release of the Sloan Digital Sky Survey. Astrophys. J. 162 (supp.), 38 (2006)

    CAS  Article  Google Scholar 

  10. Metz, M., Kroupa, P. & Jerjen, H. The spatial distribution of the Milky Way and Andromeda satellite galaxies. Mon. Not. R. Astron. Soc. 374, 1125–1145 (2007)

    ADS  Article  Google Scholar 

  11. Metz, M., Kroupa, P. & Libeskind, N. I. The orbital poles of Milky Way satellite galaxies: a rotationally supported disk of satellites. Astrophys. J. 680, 287–294 (2008)

    ADS  Article  Google Scholar 

  12. Metz, M., Kroupa, P. & Jerjen, H. Discs of satellites: the new dwarf spheroidals. Mon. Not. R. Astron. Soc. 394, 2223–2228 (2009)

    ADS  Article  Google Scholar 

  13. McConnachie, A. W. et al. The remnants of galaxy formation from a panoramic survey of the region around M31. Nature 461, 66–69 (2009)

    CAS  ADS  Article  Google Scholar 

  14. Ibata, R. A. et al. The large-scale structure of the halo of the Andromeda galaxy. I. Global stellar density, morphology and metallicity properties. Astrophys. J. 780, 128 (2014)

    ADS  Article  Google Scholar 

  15. Conn, A. R. et al. A Bayesian approach to locating the red giant branch tip magnitude. II. Distances to the satellites of M31. Astrophys. J. 758, 11 (2012)

    ADS  Article  Google Scholar 

  16. Tollerud, E. J. et al. The SPLASH survey: spectroscopy of 15 M31 dwarf spheroidal satellite galaxies. Astrophys. J. 752, 45 (2012)

    ADS  Article  Google Scholar 

  17. Collins, M. L. M. et al. A kinematic study of the Andromeda dwarf spheroidal system. Astrophys. J. 768, 172 (2013)

    ADS  Article  Google Scholar 

  18. Chiboucas, K., Jacobs, B. A., Tully, R. B. & Karachentsev, I. D. Confirmation of faint dwarf galaxies in the M81 group. Astron. J. 146, 126 (2013)

    ADS  Article  Google Scholar 

  19. Bellazzini, M., Oosterloo, T., Fraternali, F. & Beccari, G. Dwarfs walking in a row. The filamentary nature of the NGC 3109 association. Astron. Astrophys. 559, L11 (2013)

    ADS  Article  Google Scholar 

  20. Hammer, F. et al. The vast thin plane of M31 corotating dwarfs: an additional fossil signature of the M31 merger and of its considerable impact in the whole Local Group. Mon. Not. R. Astron. Soc. 431, 3543–3549 (2013)

    ADS  Article  Google Scholar 

  21. Walker, M. in Planets, Stars and Stellar Systems Vol. 5 (eds Oswalt, T. & Gilmore, G. ) 1039–1089 (Springer, 2013)

    Book  Google Scholar 

  22. Shaya, E. & Tully, B. The formation of Local Group planes of galaxies. Mon. Not. R. Astron. Soc. 436, 2096–2119 (2013)

    ADS  Article  Google Scholar 

  23. Boylan-Kolchin, M., Springel, V., White, S. D. M., Jenkins, A. & Lemson, G. Resolving cosmic structure formation with the Millennium-II simulation. Mon. Not. R. Astron. Soc. 398, 1150–1164 (2009)

    ADS  Article  Google Scholar 

  24. Guo, Q. et al. Galaxy formation in WMAP1 and WMAP7 cosmologies. Mon. Not. R. Astron. Soc. 428, 1351–1365 (2013)

    ADS  Article  Google Scholar 

  25. Komatsu, E. et al. Seven-year Wilkinson Microwave Anisotropy Probe (WMAP) observations: cosmological interpretation. Astrophys. J. 192 (supp.), 18 (2011)

    Article  Google Scholar 

  26. Bahl, H. & Baumgardt, H. A comparison of the distribution of satellite galaxies around Andromeda and the results of ΛCDM simulations. Mon. Not. R. Astron. Soc. 438, 2916–2923 (2014)

    ADS  Article  Google Scholar 

  27. Blanton, M. R. et al. New York University Value-Added Galaxy Catalog: a galaxy catalog based on new public surveys. Astron. J. 129, 2562–2578 (2005)

    ADS  Article  Google Scholar 

  28. Ade, P. A. R. et al. Planck 2013 results. XVI. Cosmological parameters. Preprint at (2013)

  29. Strauss, M. A. et al. Spectroscopic target selection in the Sloan Digital Sky Survey: the main galaxy sample. Astron. J. 124, 1810–1824 (2002)

    ADS  Article  Google Scholar 

  30. McMillan, P. J. Mass models of the Milky Way. Mon. Not. R. Astron. Soc. 414, 2446–2457 (2011)

    ADS  Article  Google Scholar 

  31. Navarro, J. F., Frenk, C. S. & White, S. D. M. A universal density profile from hierarchical clustering. Astrophys. J. 490, 493–508 (1997)

    ADS  Article  Google Scholar 

  32. Li, Y.-S. & White, S. D. M. Masses for the Local Group and the Milky Way. Mon. Not. R. Astron. Soc. 384, 1459–1468 (2008)

    ADS  Article  Google Scholar 

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Funding for the SDSS and SDSS-II has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, the US Department of Energy, the National Aeronautics and Space Administration, the Japanese Monbukagakusho, the Max Planck Society and the Higher Education Funding Council for England. The Millennium-II simulation databases used in this paper and the web application providing online access to them were constructed as part of the activities of the German Astrophysical Virtual Observatory.

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All authors assisted in the development and writing of the paper. N.G.I. primarily contributed to the development of the test for planar alignments, and R.A.I. implemented this test on the SDSS galaxy catalogue.

Corresponding author

Correspondence to Neil G. Ibata.

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The authors declare no competing financial interests.

Extended data figures and tables

Extended Data Figure 1 Adopted velocity envelope relation.

Dots mark the distance–velocity distribution of satellites in the MS2 simulation that surround isolated host galaxies of similar luminosity and mass to the Milky Way32. The empirical envelope relation shown in red (300exp[−(300 kpc/R)0.8] km s−1) is used in our analysis as a means to reduce contamination from velocity outliers.

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Ibata, N., Ibata, R., Famaey, B. et al. Velocity anti-correlation of diametrically opposed galaxy satellites in the low-redshift Universe. Nature 511, 563–566 (2014).

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