Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

The rapid assembly of an elliptical galaxy of 400 billion solar masses at a redshift of 2.3

This article has been updated


Stellar archaeology1 shows that massive elliptical galaxies formed rapidly about ten billion years ago with star-formation rates of above several hundred solar masses per year. Their progenitors are probably the submillimetre bright galaxies2 at redshifts z greater than 2. Although the mean molecular gas mass3 (5 × 1010 solar masses) of the submillimetre bright galaxies can explain the formation of typical elliptical galaxies, it is inadequate to form elliptical galaxies4 that already have stellar masses above 2 × 1011 solar masses at z ≈ 2. Here we report multi-wavelength high-resolution observations of a rare merger of two massive submillimetre bright galaxies at z = 2.3. The system is seen to be forming stars at a rate of 2,000 solar masses per year. The star-formation efficiency is an order of magnitude greater than that of normal galaxies, so the gas reservoir will be exhausted and star formation will be quenched in only around 200 million years. At a projected separation of 19 kiloparsecs, the two massive starbursts are about to merge and form a passive elliptical galaxy with a stellar mass of about 4 × 1011 solar masses. We conclude that gas-rich major galaxy mergers with intense star formation can form the most massive elliptical galaxies by z ≈ 1.5.

This is a preview of subscription content

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Multi-wavelength view of HXMM01.
Figure 2: The infrared luminosity and stellar masses of submillimetre galaxies.
Figure 3: The gas mass and dynamical state of submillimetre galaxies.

Change history

  • 19 June 2013

    The x and y axis labels of Fig. 1b were corrected.


  1. 1

    McCarthy, P. J. et al. Evolved galaxies at z>1.5 from the Gemini Deep Deep Survey: the formation epoch of massive stellar systems. Astrophys. J. 614, L9–L12 (2004)

    ADS  Article  Google Scholar 

  2. 2

    Barger, A. J. et al. Submillimetre-wavelength detection of dusty star-forming galaxies at high redshift. Nature 394, 248–251 (1998)

    CAS  ADS  Article  Google Scholar 

  3. 3

    Bothwell, M. S. et al. A survey of molecular gas in luminous sub-millimetre galaxies. Mon. Not. R. Astron. Soc. 429, 3047–3067 (2013)

    CAS  ADS  Article  Google Scholar 

  4. 4

    Damjanov, I. et al. Red nuggets at z 1.5: compact passive galaxies and the formation of the Kormendy Relation. Astrophys. J. 695, 101–115 (2009)

    ADS  Article  Google Scholar 

  5. 5

    Wardlow, J. L. et al. HerMES: candidate gravitationally lensed galaxies and lensing statistics at submillimeter wavelengths. Astrophys. J. 762, 59–86 (2013)

    ADS  Article  Google Scholar 

  6. 6

    Oliver, S. J. et al. The Herschel Multi-tiered Extragalactic Survey: HerMES. Mon. Not. R. Astron. Soc. 424, 1614–1635 (2012)

    ADS  Article  Google Scholar 

  7. 7

    Magnelli, B. et al. Dust temperature and CO→H2 conversion factor variations in the SFR-M* plane. Astron. Astrophys. 548, A22 (2012)

    Article  Google Scholar 

  8. 8

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

    CAS  ADS  Article  Google Scholar 

  9. 9

    da Cunha, E., Charlot, S. & Elbaz, D. A simple model to interpret the ultraviolet, optical and infrared emission from galaxies. Mon. Not. R. Astron. Soc. 388, 1595–1617 (2008)

    CAS  ADS  Article  Google Scholar 

  10. 10

    Davé, R. et al. The nature of submillimetre galaxies in cosmological hydrodynamic simulations. Mon. Not. R. Astron. Soc. 404, 1355–1368 (2010)

    ADS  Google Scholar 

  11. 11

    Ivison, R. J. et al. Tracing the molecular gas in distant submillimetre galaxies via CO(1–0) imaging with the Expanded Very Large Array. Mon. Not. R. Astron. Soc. 412, 1913–1925 (2011)

    CAS  ADS  Article  Google Scholar 

  12. 12

    Genzel, R. et al. A study of the gas-star formation relation over cosmic time. Mon. Not. R. Astron. Soc. 407, 2091–2108 (2010)

    CAS  ADS  Article  Google Scholar 

  13. 13

    Murray, N., Quataert, E. & Thompson, T. A. The disruption of giant molecular clouds by radiation pressure and the efficiency of star formation in galaxies. Astrophys. J. 709, 191–209 (2010)

    ADS  Article  Google Scholar 

  14. 14

    Di Matteo, T., Springel, V. & Hernquist, L. Energy input from quasars regulates the growth and activity of black holes and their host galaxies. Nature 433, 604–607 (2005)

    CAS  ADS  Article  Google Scholar 

  15. 15

    Martin, D. C. et al. The UV-optical galaxy color-magnitude diagram. III. Constraints on evolution from the blue to the red sequence. Astrophys. J. 173 (Suppl.). 342–356 (2007)

    CAS  Article  Google Scholar 

  16. 16

    van Dokkum, P. G. The recent and continuing assembly of field elliptical galaxies by red mergers. Astron. J. 130, 2647–2665 (2005)

    ADS  Article  Google Scholar 

  17. 17

    Engel, H. et al. Most submillimeter galaxies are major mergers. Astrophys. J. 724, 233–243 (2010)

    ADS  Article  Google Scholar 

  18. 18

    Chapman, S. C., Blain, A. W., Smail, I. & Ivison, R. J. A redshift survey of the submillimeter galaxy population. Astrophys. J. 622, 772–796 (2005)

    CAS  ADS  Article  Google Scholar 

  19. 19

    Ilbert, O. et al. Galaxy stellar mass assembly between 0.2 < z < 2 from the S-COSMOS survey. Astrophys. J. 709, 644–663 (2010)

    CAS  ADS  Article  Google Scholar 

  20. 20

    Strong, A. W. & Mattox, J. R. Gradient model analysis of EGRET diffuse galactic gamma-ray emission. Astron. Astrophys. 308, L21–L24 (1996)

    CAS  ADS  Google Scholar 

  21. 21

    Downes, D. & Solomon, P. M. Rotating nuclear rings and extreme starbursts in ultraluminous galaxies. Astrophys. J. 507, 615–654 (1998)

    CAS  ADS  Article  Google Scholar 

  22. 22

    Narayanan, D., Krumholz, M. R., Ostriker, E. C. & Hernquist, L. A general model for the CO-H2 conversion factor in galaxies with applications to the star formation law. Mon. Not. R. Astron. Soc. 421, 3127–3146 (2012)

    CAS  ADS  Article  Google Scholar 

  23. 23

    Magdis, G. E. et al. GOODS-Herschel: gas-to-dust mass ratios and CO-to-H2 conversion factors in normal and starbursting galaxies at high-z. Astrophys. J. 740, L15–L20 (2011)

    ADS  Article  Google Scholar 

  24. 24

    Riechers, D. A., Hodge, J., Walter, F., Carilli, C. L. & Bertoldi, F. Extended cold molecular gas reservoirs in z≈3.4 submillimeter galaxies. Astrophys. J. 739, L31–L36 (2011)

    ADS  Article  Google Scholar 

  25. 25

    Genzel, R. et al. The metallicity dependence of the CO → H2 conversion factor in z ≥ 1 star-forming galaxies. Astrophys. J. 746, 69–79 (2012)

    ADS  Article  Google Scholar 

  26. 26

    Hainline, L. J. Multi-Wavelength Properties of Submillimeter-Selected Galaxies. PhD thesis, Cal. Inst. Technol. (2008)

  27. 27

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

    CAS  ADS  Article  Google Scholar 

  28. 28

    Elbaz, D. et al. GOODS-Herschel: an infrared main sequence for star-forming galaxies. Astron. Astrophys. 533, A119 (2011)

    Article  Google Scholar 

  29. 29

    Narayanan, D., Bothwell, M. & Davé, R. Galaxy gas fractions at high redshift: the tension between observations and cosmological simulations. Mon. Not. R. Astron. Soc. 426, 1178–1184 (2012)

    CAS  ADS  Article  Google Scholar 

  30. 30

    Behroozi, P. S., Conroy, C. & Wechsler, R. H. A comprehensive analysis of uncertainties affecting the stellar mass-halo mass relation for 0 < z < 4. Astrophys. J. 717, 379–403 (2010)

    CAS  ADS  Article  Google Scholar 

Download references


Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA. This research has made use of data from the HerMES project ( HerMES is a Herschel Key Programme using Guaranteed Time from the SPIRE instrument team, ESAC scientists and a mission scientist. SPIRE has been developed by a consortium of institutes led by Cardiff University (UK) and including the University of Lethbridge (Canada); NAOC (China); CEA, LAM (France); IFSI, the University of Padua (Italy); IAC (Spain); Stockholm Observatory (Sweden); Imperial College London, RAL, UCL-MSSL, UKATC, the University of Sussex (UK); and Caltech/JPL, IPAC and the University of Colorado (USA). This development has been supported by the following national funding agencies: CSA (Canada); NAOC (China); CEA, CNES and CNRS (France); ASI (Italy); MCINN (Spain); SNSB (Sweden); STFC (UK); and NASA (USA). The data presented in this paper will be released through the HeDaM Database in Marseille at

Author information




H.F. and A.C. wrote the manuscript and led the project. C.F., R.J.I., D.A.R., M.G., R.S.B. and A.I.H. contributed significantly to the taking and analysis of the follow-up data with various instruments. All other co-authors of this paper contributed extensively and equally by their varied contributions to the HerMES project, planning of HerMES observations, analysis of HerMES data, and by commenting on this manuscript as part of an internal review process.

Corresponding authors

Correspondence to Hai Fu or Asantha Cooray.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

This file contains Supplementary Text and Data, Supplementary Figures 1-9, Supplementary Tables 1-3, Acknowledgements and additional references. (PDF 951 kb)

PowerPoint slides

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Fu, H., Cooray, A., Feruglio, C. et al. The rapid assembly of an elliptical galaxy of 400 billion solar masses at a redshift of 2.3. Nature 498, 338–341 (2013).

Download citation

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing