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GALAXY EVOLUTION

Dynamics of Lyman-α blobs

Nature Astronomy volume 4, pages 648–649 (2020)Cite this article

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Lyman-α blobs are spatially extended nebulae of hydrogen line emission that may hold clues for understanding the formation and evolution of massive galaxies at high redshifts. Recent observations and simulations suggest that multiple mechanisms can explain the origin of these objects, notably including gravitational cooling radiation.

Nebulae are astronomical objects that appear to be diffuse gas clouds in interstellar space. Pioneering astronomers in the twentieth century were fascinated by a class of spiral nebulae that we now know are entire galaxies like our own Milky Way. Their intricate distribution of stars in the spiral arms, when seen at great distances with primitive telescopes, resembled the familiar nearby gas clouds. In the twenty-first century, modern observatories capable of multi-wavelength spectroscopy have opened new windows into the distant high-redshift Universe, resulting in the discovery of yet another category of nebulae, known as Lyman-α blobs (LABs). Similar to the historic spiral nebulae, LABs are associated with massive galaxies seen at great distances. They are embedded in a characteristic, extended halo of Lyman-α (Lyα) emission tracing the surrounding atomic hydrogen gas. LABs can be over 400,000 light-years across, or more than four times the diameter of the Milky Way disk, and it remains a mystery what powers these objects. Writing in Nature Astronomy, Yiping Ao and collaborators1 present observational evidence that the Lyα emission associated with a known LAB may be powered by the gravitational potential energy of gas falling toward the central region. When combined with theoretical modelling, such enigmatic LABs provide clues about the origin of giant Lyα nebulae and their role in galaxy formation and evolution.

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Fig. 1: False colour image of a high-redshift Lyman-α blob from a cosmological zoom-in hydrodynamics simulation.

References

  1. Ao, Y. et al. Nat. Astron. https://doi.org/10.1038/s41550-020-1033-3 (2020).

    Article  Google Scholar 

  2. Partridge, R. B. & Peebles, P. J. E. Astrophys. J. 147, 868 (1967).

    Article  ADS  Google Scholar 

  3. Fynbo, J. U., Møller, P. & Warren, S. J. Mon. Not. R. Astron. Soc. 305, 849–858 (1999).

    Article  ADS  Google Scholar 

  4. Steidel, C. C. et al. Astrophys. J. 532, 170–182 (2000).

    Article  ADS  Google Scholar 

  5. Shibuya, T. et al. Publ. Astron. Soc. Jpn. 70, S14 (2018).

    Article  Google Scholar 

  6. Dijkstra, M. Publ. Astron. Soc. Aus. 31, e040 (2014).

    Article  ADS  Google Scholar 

  7. Smith, A., Safranek-Shrader, C., Bromm, V. & Milosavljević, M. Mon. Not. R. Astron. Soc. 449, 4336–4362 (2015).

    Article  ADS  Google Scholar 

  8. Feldmann, R., Hopkins, P., Quataert, E., Faucher-Giguère, C.-A. & Kereš, D. Mon. Not. R. Astron. Soc. 458, L14–L18 (2016).

    Article  ADS  Google Scholar 

  9. Hopkins, P. F. et al. Mon. Not. R. Astron. Soc. 480, 800–863 (2018).

    Article  ADS  Google Scholar 

  10. Hayes, M., Scarlata, C. & Siana, B. Nature 476, 304–307 (2011).

    Article  ADS  Google Scholar 

Download references

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  1. Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA, USA

    Aaron Smith

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Correspondence to Aaron Smith.

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Smith, A. Dynamics of Lyman-α blobs. Nat Astron 4, 648–649 (2020). https://doi.org/10.1038/s41550-020-1075-6

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