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Signs of galactic cannibalism

Nature volume 412, pages 25–26 (2001)Cite this article

Theories predict that galaxies grow by swallowing smaller galaxies, which may then show up as galactic debris. Astronomers think they have found one such tell-tale structure in a nearby galaxy.

Just as palaeontologists hunt for fossils to reconstruct the evolution of life on Earth, so astronomers hunt for ancient streams of galactic debris to reconstruct the formation history of galaxies. On page 49 of this issue, Ibata and collaborators1 report the discovery of a giant stream-like structure in the Andromeda galaxy. Andromeda is a large spiral galaxy like the Milky Way, and is one of our nearest and largest galactic neighbours. Ibata et al. propose that strong interactions between Andromeda and its smaller companion galaxies led to the formation of this stream of stars. This kind of 'fossil' demonstrates the importance of gravitational interactions in building and shaping mature galaxies, and may further our understanding of the unseen 'dark matter', which constitutes 90% of the mass of the Universe.

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Figure 1: Numerical simulation of a giant galaxy assimilating a smaller companion.
Figure 2: Our nearest neighbour is the Andromeda galaxy, which is a giant spiral galaxy like the Milky Way.

BILL SCHOENING, VANESSA HARVEY/REU PROGRAM/AURA/NOAO/NSF

References

  1. Ibata, R., Irwin, M., Lewis, G., Ferguson, A. M. N. & Tanvir, N. Nature 412, 49–52 (2001).

    Article  ADS  CAS  Google Scholar 

  2. White, S. D. M. & Rees, M. J. Mon. Not. R. Astron. Soc 183, 341–358 (1978).

    Article  ADS  Google Scholar 

  3. van den Bergh, S. et al. Astron. J 112, 359–368 (1996).

    Article  ADS  Google Scholar 

  4. Ivezic, Z. et al. Astron. J. 120, 963–977 (2000).

    Article  ADS  Google Scholar 

  5. Helmi, A., White, S. D. M., de Zeeuw P. T. & Zhao, H. S. Nature 402, 53–55 (1999).

    Article  ADS  CAS  Google Scholar 

  6. Reitzel, D. B., Guhathakurta, P. & Gould, A. Astron. J 116, 707–722 (1998).

    Article  ADS  Google Scholar 

  7. Wyse, R. F. G. & Gilmore, G. Astron. J 95, 1404–1414 (1988).

    Article  ADS  CAS  Google Scholar 

  8. Guhathakurta, P., Choi, P. I. & Reitzel, D. B. Am. Astron. Soc. Meet. 197, 3702 (2000).

    ADS  Google Scholar 

Download references

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  1. Max Planck Institut für Astrophysik, Garching bei München, D-85741, Karl Schwarzschildstrasse 1, Postfach 1317, Germany

    Amina Helmi

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  1. Amina Helmi
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Correspondence to Amina Helmi.

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Helmi, A. Signs of galactic cannibalism. Nature 412, 25–26 (2001). https://doi.org/10.1038/35083656

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