Submillimetre-bright galaxies at high redshift are the most luminous, heavily star-forming galaxies in the Universe1 and are characterized by prodigious emission in the far-infrared, with a flux of at least five millijanskys at a wavelength of 850 micrometres. They reside in haloes with masses about 1013 times that of the Sun2, have low gas fractions compared to main-sequence disks at a comparable redshift3, trace complex environments4,5 and are not easily observable at optical wavelengths6. Their physical origin remains unclear. Simulations have been able to form galaxies with the requisite luminosities, but have otherwise been unable to simultaneously match the stellar masses, star formation rates, gas fractions and environments7,8,9,10. Here we report a cosmological hydrodynamic galaxy formation simulation that is able to form a submillimetre galaxy that simultaneously satisfies the broad range of observed physical constraints. We find that groups of galaxies residing in massive dark matter haloes have increasing rates of star formation that peak at collective rates of about 500–1,000 solar masses per year at redshifts of two to three, by which time the interstellar medium is sufficiently enriched with metals that the region may be observed as a submillimetre-selected system. The intense star formation rates are fuelled in part by the infall of a reservoir gas supply enabled by stellar feedback at earlier times, not through major mergers. With a lifetime of nearly a billion years, our simulations show that the submillimetre-bright phase of high-redshift galaxies is prolonged and associated with significant mass buildup in early-Universe proto-clusters, and that many submillimetre-bright galaxies are composed of numerous unresolved components (for which there is some observational evidence11).
This is a preview of subscription content, access via your institution
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Rent or buy this article
Prices vary by article type
Prices may be subject to local taxes which are calculated during checkout
Casey, C. M., Narayanan, D. & Cooray, A. Dusty star-forming galaxies at high redshift. Phys. Rep. 541, 45–161 (2014)
Hickox, R. C. et al. The LABOCA survey of the Extended Chandra Deep Field-South: clustering of submillimetre galaxies. Mon. Not. R. Astron. Soc. 421, 284–295 (2012)
Geach, J. E. et al. On the evolution of the molecular gas fraction of star-forming galaxies. Astrophys. J. 730, L19 (2011)
Fu, H. 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)
Daddi, E. et al. Two bright submillimeter galaxies in a z = 4.05 protocluster in Goods-North, and accurate radio-infrared photometric redshifts. Astrophys. J. 694, 1517–1538 (2009)
Swinbank, A. M. et al. The rest-frame optical spectra of SCUBA galaxies. Astrophys. J. 617, 64–80 (2004)
Baugh, C. M. et al. Can the faint submillimetre galaxies be explained in the Λ cold dark matter model? Mon. Not. R. Astron. Soc. 356, 1191–1200 (2005)
Hayward, C. C. et al. Submillimetre galaxies in a hierarchical universe: number counts, redshift distribution and implications for the IMF. Mon. Not. R. Astron. Soc. 428, 2529–2547 (2013)
Shimizu, I., Yoshida, N. & Okamoto, T. Submillimetre galaxies in cosmological hydrodynamic simulations: source number counts and the spatial clustering. Mon. Not. R. Astron. Soc. 427, 2866–2875 (2012)
Davé, R. et al. The nature of submillimetre galaxies in cosmological hydrodynamic simulations. Mon. Not. R. Astron. Soc. 404, 1355–1368 (2010)
Hodge, J. A. et al. An ALMA survey of submillimeter galaxies in the extended Chandra Deep Field South: source catalog and multiplicity. Astrophys. J. 768, 91 (2013)
Hopkins, P. F. GIZMO: a new class of accurate, mesh-free hydrodynamic simulation methods. Mon. Not. R. Astron. Soc. 450, 53–110 (2015)
Davé, R., Finlator, K. & Oppenheimer, B. D. An analytic model for the evolution of the stellar, gas and metal content of galaxies. Mon. Not. R. Astron. Soc. 421, 98–107 (2012)
Hopkins, P. F. et al. Galaxies on FIRE (Feedback In Realistic Environments): stellar feedback explains cosmologically inefficient star formation. Mon. Not. R. Astron. Soc. 445, 581–603 (2014)
Feldmann, R. & Mayer, L. The Argo Simulation–I. Quenching of massive galaxies at high redshift as a result of cosmological starvation. Mon. Not. R. Astron. Soc. 446, 1939–1956 (2015)
Finkelstein, S. L. et al. A galaxy rapidly forming stars 700 million years after the Big Bang at redshift 7.51. Nature 502, 524–527 (2013)
Weiß, A. et al. ALMA redshifts of millimeter-selected galaxies from the SPT survey: the redshift distribution of dusty star-forming galaxies. Astrophys. J. 767, 88 (2013)
Ivison, R. J. et al. Herschel-ATLAS: a binary HyLIRG pinpointing a cluster of starbursting protoellipticals. Astrophys. J. 772, 137 (2013)
Hezaveh, Y. D. et al. ALMA observations of SPT-discovered, strongly lensed, dusty, star-forming galaxies. Astrophys. J. 767, 132 (2013)
Downes, D. & Solomon, P. M. Rotating nuclear rings and extreme starbursts in ultraluminous galaxies. Astrophys. J. 507, 615–654 (1998)
Michałowski, M. J. et al. The stellar masses and specific star-formation rates of submillimetre galaxies. Astron. Astrophys. 541, A85 (2012)
Behroozi, P. S., Wechsler, R. H. & Conroy, C. The average star formation histories of galaxies in dark matter halos from z = 0–8. Astrophys. J. 770, 57 (2013)
Tacconi, L. J. et al. Phibss: Molecular gas content and scaling relations in z ∼ 1–3 massive, main-sequence star-forming galaxies. Astrophys. J. 768, 74 (2013)
Simpson, J. M. et al. The SCUBA-2 cosmology legacy survey: ALMA resolves the rest-frame far-infrared emission of sub-millimeter galaxies. Astrophys. J. 799, 81 (2015)
Kennicutt, R. C. & Evans, N. J. Star formation in the Milky Way and nearby galaxies. Annu. Rev. Astron. Astrophys. 50, 531–608 (2012)
van Dokkum, P. G. et al. Confirmation of the remarkable compactness of massive quiescent galaxies at z ∼ 2.3: early-type galaxies did not form in a simple monolithic collapse. Astrophys. J. 677, L5–L8 (2008)
Murray, S. G., Power, C. & Robotham, A. S. G. HMFcalc: an online tool for calculating dark matter halo mass functions. Astron. Comput. 3–4, 23–34 (2013)
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)
Riechers, D. A. et al. A dust-obscured massive maximum-starburst galaxy at a redshift of 6.34. Nature 496, 329–333 (2013)
Vieira, J. D. et al. Dusty starburst galaxies in the early Universe as revealed by gravitational lensing. Nature 495, 344–347 (2013)
Hopkins, P. F. A general class of Lagrangian smoothed particle hydrodynamics methods and implications for fluid mixing problems. Mon. Not. R. Astron. Soc. 428, 2840–2856 (2013)
Agertz, O. et al. Fundamental differences between SPH and grid methods. Mon. Not. R. Astron. Soc. 380, 963–978 (2007)
Sijacki, D., Vogelsberger, M., Kereš, D., Springel, V. & Hernquist, L. Moving mesh cosmology: the hydrodynamics of galaxy formation. Mon. Not. R. Astron. Soc. 424, 2999–3027 (2012)
Hayward, C. C., Torrey, P., Springel, V., Hernquist, L. & Vogelsberger, M. Galaxy mergers on a moving mesh: a comparison with smoothed particle hydrodynamics. Mon. Not. R. Astron. Soc. 442, 1996–2016 (2014)
Faucher-Giguère, C.-A. et al. Neutral hydrogen in galaxy haloes at the peak of the cosmic star formation history. Mon. Not. R. Astron. Soc. 449, 987–1003 (2015)
Springel, V., Di Matteo, T. & Hernquist, L. Modelling feedback from stars and black holes in galaxy mergers. Mon. Not. R. Astron. Soc. 361, 776–794 (2005)
Barnes, J. E. Gravitational softening as a smoothing operation. Mon. Not. R. Astron. Soc. 425, 1104–1120 (2012)
Hahn, O. & Abel, T. Multi-scale initial conditions for cosmological simulations. Mon. Not. R. Astron. Soc. 415, 2101–2121 (2011)
Hopkins, P. F., Quataert, E. & Murray, N. Self-regulated star formation in galaxies via momentum input from massive stars. Mon. Not. R. Astron. Soc. 417, 950–973 (2011)
Hopkins, P. F., Quataert, E. & Murray, N. The structure of the interstellar medium of star-forming galaxies. Mon. Not. R. Astron. Soc. 421, 3488–3521 (2012)
Hopkins, P. F., Narayanan, D., Murray, N. & Quataert, E. Dense molecular gas: a sensitive probe of stellar feedback models. Mon. Not. R. Astron. Soc. 433, 69–77 (2013)
Hopkins, P. F. et al. Star formation in galaxy mergers with realistic models of stellar feedback and the interstellar medium. Mon. Not. R. Astron. Soc. 430, 1901–1927 (2013)
Hopkins, P. F. et al. Resolving the generation of starburst winds in Galaxy mergers. Mon. Not. R. Astron. Soc. 433, 78–97 (2013)
Narayanan, D. & Hopkins, P. F. Why is the Milky Way X-factor constant? Mon. Not. R. Astron. Soc. 433, 1223–1229 (2013)
Katz, N., Weinberg, D. H. & Hernquist, L. Cosmological simulations with TreeSPH. Astrophys. J. Suppl. Ser. 105, 19–35 (1996)
Ferland, G. J. et al. The 2013 Release of Cloudy. Rev. Mex. Astron. Astrofis. 49, 137–163 (2013)
Krumholz, M. R., McKee, C. F. & Tumlinson, J. The atomic-to-molecular transition in galaxies. I. An analytic approximation for photodissociation fronts in finite clouds. Astrophys. J. 689, 865–882 (2008)
Krumholz, M. R. & Gnedin, N. Y. A comparison of methods for determining the molecular content of model galaxies. Astrophys. J. 729, 36 (2011)
Hopkins, P. F., Narayanan, D. & Murray, N. The meaning and consequences of star formation criteria in galaxy models with resolved stellar feedback. Mon. Not. R. Astron. Soc. 432, 2647–2653 (2013)
Kroupa, P. The initial mass function of stars: evidence for uniformity in variable systems. Science 295, 82–91 (2002)
Leitherer, C. et al. Starburst99: synthesis models for galaxies with active star formation. Astrophys. J. Suppl. Ser. 123, 3–40 (1999)
Mannucci, F., Della Valle, M. & Panagia, N. Two populations of progenitors for Type Ia supernovae? Mon. Not. R. Astron. Soc. 370, 773–783 (2006)
Bellovary, J. et al. The relative role of galaxy mergers and cosmic flows in feeding black holes. Astrophys. J. 779, 136 (2013)
Anglés-Alcázar, D. et al. Torque-limited growth of massive black holes in galaxies across cosmic time. Astrophys. J. 800, 127 (2015)
Hopkins, P. F., Kocevski, D. D. & Bundy, K. Do we expect most AGN to live in discs? Mon. Not. R. Astron. Soc. 445, 823–834 (2014)
Kocevski, D. D. et al. CANDELS: constraining the AGN-merger connection with host morphologies at z ∼ 2. Astrophys. J. 744, 148 (2012)
Treister, E., Schawinski, K., Urry, C. M. & Simmons, B. D. Major galaxy mergers only trigger the most luminous active galactic nuclei. Astrophys. J. 758, L39 (2012)
Governato, F. et al. The Local Group as a test of cosmological models. New Astron. Rev. 2, 91–106 (1997)
Stadel, J. G. Cosmological N-body Simulations and their Analysis. Ph.D. thesis, Univ. Washington (2001)
Thompson, R. pyGadgetReader: GADGET snapshot reader for python. Astrophysics Source Code Library 1411.001 (2014)
Thompson, R. SPHGR: Smoothed-Particle Hydrodynamics Galaxy Reduction. Astrophysics Source Code Library 1502.012 (2015)
Turk, M. J. et al. yt: A multi-code analysis toolkit for astrophysical simulation data. Astrophys. J. Suppl. Ser. 192, 9 (2011)
Conroy, C., Gunn, J. E. & White, M. The propagation of uncertainties in stellar population synthesis modeling. I. The relevance of uncertain aspects of stellar evolution and the initial mass function to the derived physical properties of galaxies. Astrophys. J. 699, 486–506 (2009)
Conroy, C. & Gunn, J. E. The propagation of uncertainties in stellar population synthesis modeling. III. Model calibration, comparison, and evaluation. Astrophys. J. 712, 833–857 (2010)
Robitaille, T. P. HYPERION: an open-source parallelized three-dimensional dust continuum radiative transfer code. Astron. Astrophys. 536, A79 (2011)
Lucy, L. B. Computing radiative equilibria with Monte Carlo techniques. Astron. Astrophys. 344, 282–288 (1999)
Weingartner, J. C. & Draine, B. T. Dust grain-size distributions and extinction in the Milky Way, Large Magellanic Cloud, and Small Magellanic Cloud. Astrophys. J. 548, 296–309 (2001)
Robitaille, T. P. et al. A self-consistent model of Galactic stellar and dust infrared emission and the abundance of polycyclic aromatic hydrocarbons. Astron. Astrophys. 545, A39 (2012)
Dwek, E. The evolution of the elemental abundances in the gas and dust phases of the galaxy. Astrophys. J. 501, 643–665 (1998)
Vladilo, G. Dust and elemental abundances in damped Lyα absorbers. Astrophys. J. 493, 583–594 (1998)
Watson, D. The Galactic dust-to-metals ratio and metallicity using gamma-ray bursts. Astron. Astrophys. 533, A16 (2011)
Pascucci, I. et al. The 2D continuum radiative transfer problem. Benchmark results for disk configurations. Astron. Astrophys. 417, 793–805 (2004)
Jonsson, P. SUNRISE: polychromatic dust radiative transfer in arbitrary geometries. Mon. Not. R. Astron. Soc. 372, 2–20 (2006)
Jonsson, P., Groves, B. A. & Cox, T. J. High-resolution panchromatic spectral models of galaxies including photoionization and dust. Mon. Not. R. Astron. Soc. 186 (2010)
Torrey, P. et al. Synthetic galaxy images and spectra from the Illustris simulation. Mon. Not. R. Astron. Soc. 447, 2753–2771 (2015)
Ade, P. A. R. et al. Planck 2013 results. XVI. Cosmological parameters. Astron. Astrophys. 571, A16 (2014)
González, J. E., Lacey, C. G., Baugh, C. M. & Frenk, C. S. The role of submillimetre galaxies in hierarchical galaxy formation. Mon. Not. R. Astron. Soc. 413, 749–762 (2011)
Hainline, L. J. et al. The stellar mass content of submillimeter-selected galaxies. Astrophys. J. 740, 96 (2011)
Michałowski, M. J. et al. Determining the stellar masses of submillimetre galaxies: the critical importance of star formation histories. Astron. Astrophys. 571, A75 (2014)
Bothwell, M. S. et al. A survey of molecular gas in luminous sub-millimetre galaxies. Mon. Not. R. Astron. Soc. 429, 3047–3067 (2013)
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)
Tacconi, L. J. et al. Submillimeter galaxies at z ∼ 2: evidence for major mergers and constraints on lifetimes, IMF, and CO-H2 conversion factor. Astrophys. J. 680, 246–262 (2008)
Chakrabarti, S., Fenner, Y., Cox, T. J., Hernquist, L. & Whitney, B. A. An evolutionary model for submillimeter galaxies. Astrophys. J. 688, 972–989 (2008)
Narayanan, D., Cox, T. J., Hayward, C. C., Younger, J. D. & Hernquist, L. The star-forming molecular gas in high-redshift submillimetre galaxies. Mon. Not. R. Astron. Soc. 400, 1919–1935 (2009)
Narayanan, D. et al. The formation of high-redshift submillimetre galaxies. Mon. Not. R. Astron. Soc. 401, 1613–1619 (2010)
Hayward, C. C. et al. What does a submillimeter galaxy selection actually select? The dependence of submillimeter flux density on star formation rate and dust mass. Astrophys. J. 743, 159 (2011)
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)
We thank M. J. Michałowski for providing observational data. Partial support for D.N. was provided by NSF AST-1009452, AST-1442650, NASA HST AR-13906.001 and a Cottrell College Science Award. P.H., C.H., M.T. and R.T. were funded by the Gordon and Betty Moore Foundation (GBMF4561 and grant no. 776). P.H. acknowledges the Alfred P. Sloan Foundation for support. C.-A.F.-G. was supported by NASA awards PF3-140106, NNX15AB22G and NSF AST-1412836. D.K. was supported by NSF AST-1412153. R.F. was supported by NASA HF-51304.01-A, and is a Hubble fellow. The simulations here were run on Stampede at TACC through NSF XSEDE allocations TG-AST120025, TG-AST130039 and TG-AST140023, NASA Pleiades, and the Haverford College cluster.
The authors declare no competing financial interests.
Extended data figures and tables
Extended Data Figure 1 Mass of reservoir gas in the central galaxy that will be consumed during SMG starburst as a function of z.
The colour scale denotes the median scale height from the galaxy centre of mass. The gas mass consumed during the starburst is calculated by tracking the evolution of gas particles that turn into stars during the SMG phase (z ≈ 2–2.7), and is only measured for the central galaxy itself (that is, gas ejected into the halo is not included). The SMG gas reservoir follows a cycle of being pushed outward followed by re-accretion.
Extended Data Figure 2 Distribution of flux density ratio of brightest component in submillimetre-luminous region to total flux density.
The average is shown with the vertical line. Submillimetre-luminous regions often break up into multiples. The region is generally dominated by one component, although smaller subhaloes can contribute on average ∼30% of the observed flux density. The normalization of the ordinate, P, is arbitrary.
The blue histogram shows the distribution of gas surface densities (Σgas) during all phases (that is, all snapshots, Snaps), while the pink histogram shows the same for the submillimetre-luminous phase. The ordinate (N) is weighted by the time a galaxy spends in a given gas surface density bin, and the normalization is arbitrary. We predict that the submillimetre-luminous phases do not have dramatically different surface density distributions compared to the non-submillimetre-luminous phases. This prediction might have been tentatively observed1,87.
Blue stars show individual snapshots of the central submillimetre galaxy, while red circles with error bars (1σ) show observations of BzK galaxies and SMGs with direct CO(J = 1–0) measurements (to avoid complications in converting from higher-lying CO rotational lines to the ground state for a mass conversion). (BzK galaxies are those that have been selected on the basis of their B, z and K band luminosities.) Both the observations and our model show a declining molecular gas fraction (fgas) with increasing galaxy mass (M*), with a typical range of fgas = 0.1–0.4 for galaxies of SMG mass.
Extended Data Figure 5 Predicted spectral energy distribution (SED) for the central submillimetre galaxy.
The ordinate shows the flux density in mJy, while the abscissa shows the wavelength in μm. The blue shaded region shows the range of SEDs for all simulation snapshots that satisfy the fiducial F850μm > 5 mJy submillimetre galaxy selection criteria, while the dark grey points with error bars (1σ) are a compilation of observed data. The individual coloured lines show the SEDs for individual submillimetre-luminous snapshots. The data and models are redshifted to a common redshift z = 2. The model and data compare well, and the model suggests a diverse range of SMG SEDs.
The ordinate denotes the SFR as determined from the infrared SED (SFRIR)25, while the abscissa shows the SFR averaged over the last 50 Myr in the simulations (SFR50). Up to an SFR of ∼800 M⊙ yr−1 the two correspond well. At higher SFRs, however, there is a dramatic departure owing to substantial contribution to the infrared luminosity by older stars.
Lines show the 850 μm duty cycle above a given flux density as a function of flux density for our resolution test models presented in Methods. SR denotes our standard resolution (the resolution of our main model) while HR is a one-level-higher refinement.
The purple line shows model results, while the dark-blue filled region shows observational constraints from an abundance matching assumption22. The model and observations are in reasonable agreement, especially during the submillimetre-luminous phase (vertical shaded region). At late times, the stellar mass of the galaxy is a factor of ∼2 higher than the median observed galaxy.
The simulated galaxy for these tests is our lowest resolution cosmological simulation (m13m14). Each panel shows the 850 μm flux density light curve of the tested model, with time noted on the abscissa (redshift on the bottom, time since the Big Bang on the top). In all panels, the shaded region denotes S850 ≥ 5 mJy, which is the canonical selection criteria for SMGs. Top left, our fiducial set of parameters; top right, simulation with a 100 kpc (on a side) emission region instead of 200 kpc; bottom left, simulation with our model for PAHs turned off; bottom right, fiducial simulation run with ten times the number of photons.
About this article
Cite this article
Narayanan, D., Turk, M., Feldmann, R. et al. The formation of submillimetre-bright galaxies from gas infall over a billion years. Nature 525, 496–499 (2015). https://doi.org/10.1038/nature15383
This article is cited by
Nature Physics (2016)