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Strongly baryon-dominated disk galaxies at the peak of galaxy formation ten billion years ago


In the cold dark matter cosmology, the baryonic components of galaxies—stars and gas—are thought to be mixed with and embedded in non-baryonic and non-relativistic dark matter, which dominates the total mass of the galaxy and its dark-matter halo1. In the local (low-redshift) Universe, the mass of dark matter within a galactic disk increases with disk radius, becoming appreciable and then dominant in the outer, baryonic regions of the disks of star-forming galaxies. This results in rotation velocities of the visible matter within the disk that are constant or increasing with disk radius—a hallmark of the dark-matter model2. Comparisons between the dynamical mass, inferred from these velocities in rotational equilibrium, and the sum of the stellar and cold-gas mass at the peak epoch of galaxy formation ten billion years ago, inferred from ancillary data, suggest high baryon fractions in the inner, star-forming regions of the disks3,4,5,6. Although this implied baryon fraction may be larger than in the local Universe, the systematic uncertainties (owing to the chosen stellar initial-mass function and the calibration of gas masses) render such comparisons inconclusive in terms of the mass of dark matter7. Here we report rotation curves (showing rotation velocity as a function of disk radius) for the outer disks of six massive star-forming galaxies, and find that the rotation velocities are not constant, but decrease with radius. We propose that this trend arises because of a combination of two main factors: first, a large fraction of the massive high-redshift galaxy population was strongly baryon-dominated, with dark matter playing a smaller part than in the local Universe; and second, the large velocity dispersion in high-redshift disks introduces a substantial pressure term that leads to a decrease in rotation velocity with increasing radius. The effect of both factors appears to increase with redshift. Qualitatively, the observations suggest that baryons in the early (high-redshift) Universe efficiently condensed at the centres of dark-matter haloes when gas fractions were high and dark matter was less concentrated.

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Figure 1: Hα gas dynamics from KMOS and SINFONI in six massive star-forming galaxies.
Figure 2: Normalized rotation curves.
Figure 3: Dark-matter fractions.


  1. 1

    White, S. D. M. & Rees, M. J. Core condensation in heavy halos: a two-stage theory for galaxy formation and clustering. Mon. Not. R. Astron. Soc. 183, 341–358 (1978)

    ADS  Google Scholar 

  2. 2

    Sofue, Y. & Rubin, V. Rotation curves of spiral galaxies. Annu. Rev. Astron. Astrophys. 39, 137–174 (2001)

    ADS  CAS  Google Scholar 

  3. 3

    Förster Schreiber, N. M. et al. The SINS survey: SINFONI integral field spectroscopy of z ~ 2 star-forming galaxies. Astrophys. J. 706, 1364–1428 (2009)

    ADS  Google Scholar 

  4. 4

    van Dokkum, P. G. et al. Forming compact massive galaxies. Astrophys. J. 813, 23 (2015)

    ADS  Google Scholar 

  5. 5

    Price, S. H. et al. The MOSDEF survey: dynamical and baryonic masses and kinematic structures of star-forming galaxies at 1.4 ≤ z ≤ 2.6. Astrophys. J. 819, 80 (2016)

    ADS  Google Scholar 

  6. 6

    Wuyts, S. et al. KMOS3D: dynamical constraints on the mass budget in early star-forming disks. Astrophys. J. 831, 149 (2016)

    ADS  Google Scholar 

  7. 7

    Courteau, S. & Dutton, A. A. On the global mass distribution in disk galaxies. Astrophys. J. 801, L20 (2015)

    ADS  Google Scholar 

  8. 8

    Wisnioski, E. et al. The KMOS3D survey: design, first results, and the evolution of galaxy kinematics from 0.7 ≤ z ≤ 2.7. Astrophys. J. 799, 209 (2015)

    ADS  Google Scholar 

  9. 9

    Grogin, N. A. et al. CANDELS: the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey. Astrophys. J. Suppl. Ser. 197, 35 (2011)

    ADS  Google Scholar 

  10. 10

    Koekemoer, A. M. et al. CANDELS: the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey—the Hubble Space Telescope observations, imaging data products, and mosaics. Astrophys. J. Suppl. Ser. 197, 36 (2011)

    ADS  Google Scholar 

  11. 11

    Kong, X. et al. A wide area survey for high-redshift massive galaxies. I. Number counts and clustering of BzKs and EROs. Astrophys. J. 638, 72–87 (2006)

    ADS  CAS  Google Scholar 

  12. 12

    Brammer, G. B. et al. 3D-HST: a wide-field grism spectroscopic survey with the Hubble Space Telescope . Astrophys. J. Suppl. Ser. 200, 13 (2012)

    ADS  Google Scholar 

  13. 13

    Momcheva, I. G. et al. The 3D-HST survey: Hubble Space Telescope WFC3/G141 grism spectra, redshifts, and emission line measurements for ~100,000 galaxies. Astrophys. J. Suppl. Ser. 225, 27 (2016)

    ADS  Google Scholar 

  14. 14

    Burkert, A. et al. High-redshift star-forming galaxies: angular momentum and baryon fraction, turbulent pressure effects, and the origin of turbulence. Astrophys. J. 725, 2324–2332 (2010)

    ADS  CAS  Google Scholar 

  15. 15

    Casertano, S. & van Gorkom, J. H. Declining rotation curves: the end of a conspiracy? Astron. J. 101, 1231–1241 (1991)

    ADS  CAS  Google Scholar 

  16. 16

    Honma, M. & Sofue, Y. On the Keplerian rotation curves of galaxies. Publ. Astron. Soc. Jap. 49, 539–545 (1997)

    ADS  Google Scholar 

  17. 17

    Carignan, C., Chemin, L., Huchtmeier, W. K. & Lockman, F. J. The extended H i rotation curve and mass distribution of M31. Astrophys. J. 641, L109–L112 (2006)

    ADS  CAS  Google Scholar 

  18. 18

    Lang, P. et al. Falling outer rotation curves of star-forming galaxies at0.6 ≤ z ≤2.6 probed with KMOS3D and SINS/zC-SINF (submitted)

  19. 19

    Catinella, B., Giovanelli, R. & Haynes, M. P. Template rotation curves for disk galaxies. Astrophys. J. 640, 751–761 (2006)

    ADS  CAS  Google Scholar 

  20. 20

    Bland-Hawthorn, J. & Gerhard, O. The galaxy in context: structural, kinematic, and integrated properties. Annu. Rev. Astron. Astrophys. 54, 529–596 (2016)

    ADS  CAS  Google Scholar 

  21. 21

    Freeman, K. On the disks of spiral and S0 galaxies. Astrophys. J. 160, 811–830 (1970)

    ADS  Google Scholar 

  22. 22

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

    ADS  Google Scholar 

  23. 23

    Cappellari, M. et al. The ATLAS3D project – XV. Benchmark for early-type galaxies scaling relations from 260 dynamical models: mass-to-light ratio, dark matter, fundamental plane and mass plane. Mon. Not. R. Astron. Soc. 432, 1709–1741 (2013)

    ADS  Google Scholar 

  24. 24

    Peng, Y. et al. Mass and environment as drivers of galaxy evolution in SDSS and zCOSMOS and the origin of the Schechter function. Astrophys. J. 721, 193–221 (2010)

    ADS  Google Scholar 

  25. 25

    Genzel, R. et al. Combined CO and dust scaling relations of depletion time and molecular gas fractions with cosmic time, specific star-formation rate, and stellar mass. Astrophys. J. 800, 20 (2015)

    ADS  Google Scholar 

  26. 26

    van der Wel, A. et al. 3D-HST+CANDELS: the evolution of the galaxy size-mass distribution since z = 3. Astrophys. J. 788, 28 (2014)

    ADS  Google Scholar 

  27. 27

    Guo, Q. & White, S. D. M. Galaxy growth in the concordance ΛCDM cosmology. Mon. Not. R. Astron. Soc. 384, 2–10 (2008)

    ADS  Google Scholar 

  28. 28

    Oser, L., Ostriker, J. P., Naab, T., Johansson, P. H. & Burkert, A. The two phases of galaxy formation. Astrophys. J. 725, 2312–2323 (2010)

    ADS  CAS  Google Scholar 

  29. 29

    Zolotov, A. et al. Compaction and quenching of high-z galaxies in cosmological simulations: blue and red nuggets. Mon. Not. R. Astron. Soc. 450, 2327–2353 (2015)

    ADS  CAS  Google Scholar 

  30. 30

    Moster, B. P., Naab, T. & White, S. D. M. Galactic star formation and accretion histories from matching galaxies to dark matter haloes. Mon. Not. R. Astron. Soc. 428, 3121–3138 (2013)

    ADS  Google Scholar 

  31. 31

    Mancini, C. et al. The zCOSMOS-SINFONI Project. I. Sample selection and natural-seeing observations. Astrophys. J. 743, 86 (2011)

    ADS  Google Scholar 

  32. 32

    Eisenhauer, F. et al. The Universe in 3D: first observations with SPIFFI, the infrared integral field spectrometer for the VLT. The Messenger 113, 17–25 (2003)

    ADS  Google Scholar 

  33. 33

    Bonnet, H. et al. First light of SINFONI at the VLT. The Messenger 117, 17–24 (2004)

    ADS  Google Scholar 

  34. 34

    Sharples, R. M. et al. First light for the KMOS multi-object integral field spectrometer. The Messenger 151, 21–23 (2012)

    ADS  Google Scholar 

  35. 35

    Burkert, A. et al. The angular momentum distribution and baryon content of star-forming galaxies at z ~ 1-3. Astrophys. J. 826, 214 (2016)

    ADS  Google Scholar 

  36. 36

    Skelton, R. E. et al. 3D-HST WFC4-selected photometric catalogs in the five CANDELS/3D-HST fields: photometry, photometric redshifts, and stellar masses. Astrophys . J. Suppl. Ser. 214, 24 (2014)

    ADS  Google Scholar 

  37. 37

    Whitaker, K. E. et al. Constraining the low-mass slope of the star formation sequence at 0.5 < z < 2.5. Astrophys. J. 795, 104 (2014)

    ADS  Google Scholar 

  38. 38

    van Dokkum, P. G. et al. First results from the 3D-HST survey: the striking diversity of massive galaxies at z > 1. Astrophys. J. 743, L15 (2011)

    ADS  Google Scholar 

  39. 39

    Wuyts, S. et al. On star formation rates and star formation histories of galaxies out to z ~ 3. Astrophys. J. 738, 106 (2011)

    ADS  Google Scholar 

  40. 40

    Bruzual, G. & Charlot, S. Stellar population synthesis at the resolution of 2003. Mon. Not. R. Astron. Soc. 344, 1000–1028 (2003)

    ADS  Google Scholar 

  41. 41

    Calzetti, D. et al. The dust content and opacity of actively star-forming galaxies. Astrophys. J. 533, 682–695 (2000)

    ADS  Google Scholar 

  42. 42

    Chabrier, G. Galactic stellar and substellar initial mass function. Publ. Astron. Soc. Pac. 115, 763–795 (2003)

    ADS  Google Scholar 

  43. 43

    Wuyts, E. et al. A consistent study of metallicity evolution at 0.8 < z < 2.6. Astrophys. J. 789, L40 (2014)

    ADS  Google Scholar 

  44. 44

    Wuyts, E. et al. The evolution of metallicity and metallicity gradients from z = 2.7 to 0.6 with KMOS3D . Astrophys. J. 827, 74 (2016)

    ADS  Google Scholar 

  45. 45

    Erb, D. K. et al. The mass-metallicity relation at z ≥ 2. Astrophys. J. 644, 813–828 (2006)

    ADS  CAS  Google Scholar 

  46. 46

    Zahid, H. J., Kewley, L. J. & Bresoline, F. The mass-metallicity and luminosity-metallicity relations from DEEP2 at z ~ 0.8. Astrophys. J. 730, 137 (2011)

    ADS  Google Scholar 

  47. 47

    Zahid, H. J. et al. The FMOS-COSMOS survey of star-forming galaxies at z ~ 1.6. II. The mass-metallicity relation and the dependence on star formation rate and dust extinction. Astrophys. J. 792, 75 (2014)

    ADS  Google Scholar 

  48. 48

    Stott, J. P. et al. A fundamental metallicity relation for galaxies at z = 0.84–1.47 from HiZELS. Mon. Not. R. Astron. Soc. 436, 1130–1141 (2013)

    ADS  CAS  Google Scholar 

  49. 49

    Steidel, C. C. et al. Strong nebular line ratios in the spectra of z ~ 2–3 star-forming galaxies: first results from KBSS-MOSFIRE. Astrophys. J. 795, 165 (2014)

    ADS  Google Scholar 

  50. 50

    Sanders, R. L. et al. The MOSDEF survey: mass, metallicity, and star-formation rate at z ~ 2.3. Astrophys. J. 799, 138 (2015)

    ADS  CAS  Google Scholar 

  51. 51

    Wuyts, S. et al. What do we learn from IRAC observations of galaxies at 2 < z < 3.5? Astrophys. J. 655, 51–65 (2007)

    CAS  Google Scholar 

  52. 52

    Kewley, L. J. et al. Theoretical evolution of optical strong lines across cosmic time. Astrophys. J. 774, 100 (2013)

    ADS  Google Scholar 

  53. 53

    Tacconi, L. J. et al. PHIBSS: unified scaling relations of depletion time and molecular gas fractions with cosmic time, specific star formation rate and stellar mass. Preprint at (2017)

  54. 54

    Förster Schreiber, N. M. et al. Constraints on the assembly and dynamics of galaxies. I. Detailed rest-frame optical morphologies on kiloparsec scale of z ~ 2 star-forming galaxies. Astrophys. J. 731, 65 (2011)

    ADS  Google Scholar 

  55. 55

    Förster Schreiber, N. M. et al. Constraints on the assembly and dynamics of galaxies. II. Properties of kiloparsec-scale clumps in rest-frame optical emission of z ~ 2 star-forming galaxies. Astrophys. J. 739, 45 (2011)

    ADS  Google Scholar 

  56. 56

    Wuyts, S. et al. Smooth(er) stellar mass maps in CANDELS: constrains on the longevity of clumps in high-redshift star-forming galaxies. Astrophys. J. 753, 114 (2012)

    ADS  Google Scholar 

  57. 57

    Lang, P. et al. Bulge growth and quenching since z = 2.5 in CANDELS/3D-HST. Astrophys. J. 788, 11 (2014)

    ADS  Google Scholar 

  58. 58

    Tacchella, S. et al. The confinement of star-forming galaxies into a main sequence through episodes of gas compaction, depletion and replenishment. Mon. Not. R. Astron. Soc. 457, 2790–2813 (2016)

    ADS  CAS  Google Scholar 

  59. 59

    Tacchella, S. et al. Evolution of density profiles in high-z galaxies: compaction and quenching inside-out. Mon. Not. R. Astron. Soc. 458, 242–263 (2016)

    ADS  CAS  Google Scholar 

  60. 60

    Wuyts, S. et al. A CANDELS-3D-HST synergy: resolved star formation patterns at 0.7 < z < 1.5. Astrophys. J. 779, 135 (2013)

    ADS  Google Scholar 

  61. 61

    Genzel, R. et al. The SINS/zC-SINF survey of z ~ 2 galaxy kinematics: evidence for gravitational quenching. Astrophys. J. 785, 75 (2014)

    ADS  Google Scholar 

  62. 62

    Nelson, E. J. et al. Where stars form: inside-out growth and coherent star formation from HST Hα maps of 3200 galaxies across the main sequence at 0.7 < z < 1.5. Astrophys. J. 828, 27 (2016)

    ADS  Google Scholar 

  63. 63

    Tacchella, S. et al. Evidence for mature bulges and an inside-out quenching phase 3 billion years after the Big Bang. Science 348, 314–317 (2015)

    ADS  CAS  PubMed  Google Scholar 

  64. 64

    Tacchella, S. et al. SINS/zC-SINF survey of z ~ 2 galaxy kinematics: rest-frame morphology, structure, and colors from near-infrared Hubble Space Telescope imaging. Astrophys. J. 802, 101 (2015)

    ADS  Google Scholar 

  65. 65

    Wuyts, S. et al. Galaxy structure and mode of star formation in the SFR-mass plane from z ~ 2.5 to z ~ 0.1. Astrophys. J. 742, 96 (2011)

    ADS  Google Scholar 

  66. 66

    Bell, E. F. et al. What turns galaxies off? The different morphologies of star-forming and quiescent galaxies since z ~ 2 from CANDELS. Astrophys. J. 753, 167 (2012)

    ADS  Google Scholar 

  67. 67

    Bruce, V. A. et al. The bulge–disc decomposed evolution of massive galaxies at 1 < z < 3 in CANDELS. Mon. Not. R. Astron. Soc. 444, 1001–1033 (2014)

    ADS  Google Scholar 

  68. 68

    Bruce, V. A. et al. The decomposed bulge and disc size–mass relations of massive galaxies at 1 < z < 3 in CANDELS. Mon. Not. R. Astron. Soc. 444, 1660–1673 (2014)

    ADS  Google Scholar 

  69. 69

    Nelson, E. J. et al. Spatially resolved dust maps from Balmer decrements in galaxies at z ~ 1.4. Astrophys. J. 817, L9 (2016)

    ADS  Google Scholar 

  70. 70

    Tadaki, K. et al. SXDF-ALMA 1.5 arcmin2 deep survey: a compact dusty star-forming galaxy at z = 2.5. Astrophys. J. 811, L3 (2015)

    ADS  Google Scholar 

  71. 71

    Tadaki, K.-i. et al. Bulge-forming galaxies with an extended rotating disk at z ~ 2. Astrophys. J. 834, 135 (2017)

    ADS  Google Scholar 

  72. 72

    Barro, G. et al. Sub-kiloparsec ALMA imaging of compact star-forming galaxies at z ~ 2.5: revealing the formation of dense galactic cores in the progenitors of compact quiescent galaxies. Astrophys. J. 827, L32 (2016)

    ADS  Google Scholar 

  73. 73

    van der Wel, A. et al. Geometry of star-forming galaxies from SDSS, 3D-HST, and CANDELS. Astrophys. J. 792, L6 (2014)

    ADS  Google Scholar 

  74. 74

    Elmegreen, D. M. et al. Galaxy morphologies in the Hubble ultra deep field: dominance of linear structures at the detection limit. Astrophys. J. 631, 85–100 (2005)

    ADS  Google Scholar 

  75. 75

    Law, D. R. et al. An HST/WFC3-IR morphological survey of galaxies at z = 1.5–3.6. I. Survey description and morphological properties of star-forming galaxies. Astrophys. J. 745, 85 (2012)

    ADS  Google Scholar 

  76. 76

    Genzel, R. et al. The rapid formation of a large rotating disk galaxy three billion years after the Big Bang. Nature 442, 786–789 (2006)

    ADS  CAS  PubMed  Google Scholar 

  77. 77

    Kassin, S. et al. The epoch of disk settling: z ~ 1 to now. Astrophys. J. 758, 106 (2012)

    ADS  Google Scholar 

  78. 78

    Newman, S. F. et al. The SINS/zC-SINF survey of z ~ 2 galaxy kinematics: the nature of dispersion-dominated galaxies. Astrophys. J. 767, 104 (2013)

    ADS  Google Scholar 

  79. 79

    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)

    ADS  Google Scholar 

  80. 80

    Davies, R. et al. How well can we measure the intrinsic velocity dispersion of distant disk galaxies? Astrophys. J. 741, 69 (2011)

    ADS  Google Scholar 

  81. 81

    van der Kruit, P. C. & Allen, R. J. The kinematics of spiral and irregular galaxies. Annu. Rev. Astron. Astrophys. 16, 103–139 (1978)

    ADS  Google Scholar 

  82. 82

    Genzel, R. et al. The Sins survey of z ~ 2 galaxy kinematics: properties of the giant star-forming clumps. Astrophys. J. 733, 101 (2011)

    ADS  Google Scholar 

  83. 83

    Newman, S. F. et al. Shocked superwinds from the z ~ 2 clumpy star-forming galaxy, ZC406690. Astrophys. J. 752, 111 (2012)

    ADS  Google Scholar 

  84. 84

    Förster Schreiber, N. M. et al. The SINS/zC-SINF survey of z ~ 2 galaxy kinematics: evidence for powerful active galactic nucleus-driven nuclear outflows in massive star-forming galaxies. Astrophys. J. 787, 38 (2014)

    ADS  Google Scholar 

  85. 85

    Cappellari, M. Structure and kinematics of early-type galaxies from integral field spectroscopy. Annu. Rev. Astron. Astrophys. 54, 597–665 (2016)

    ADS  CAS  Google Scholar 

  86. 86

    Noordermeer, E. The rotation curves of flattened Sérsic bulges. Mon. Not. R. Astron. Soc. 385, 1359–1364 (2008)

    ADS  Google Scholar 

  87. 87

    Bullock, J. S. et al. Profiles of dark haloes: evolution, scatter and environment. Mon. Not. R. Astron. Soc. 321, 559–575 (2001)

    ADS  Google Scholar 

  88. 88

    Gao, L. et al. The redshift dependence of the structure of massive Λ cold dark matter haloes. Mon. Not. R. Astron. Soc. 387, 536–544 (2008)

    ADS  CAS  Google Scholar 

  89. 89

    Dutton, A. A. & Macciò, A. V. Cold dark matter haloes in the Planck era: evolution of structural parameters for Einasto and NFW profiles. Mon. Not. R. Astron. Soc. 441, 3359–3374 (2014)

    ADS  Google Scholar 

  90. 90

    Johansson, P. H., Naab, T. & Ostriker, J. P. Gravitational heating helps make massive galaxies red and dead. Astrophys. J. 697, L38–L43 (2009)

    ADS  CAS  Google Scholar 

  91. 91

    Dutton, A. A. et al. The response of dark matter haloes to elliptical galaxy formation: a new test for quenching scenarios. Mon. Not. R. Astron. Soc. 453, 2447–2464 (2015)

    ADS  CAS  Google Scholar 

  92. 92

    Duffy, A. R. et al. Impact of baryon physics on dark matter structures: a detailed simulation study of halo density profiles. Mon. Not. R. Astron. Soc. 405, 2161–2178 (2010)

    ADS  CAS  Google Scholar 

  93. 93

    Pontzen, A. & Governato, F. How supernova feedback turns dark matter cusps into cores. Mon. Not. R. Astron. Soc. 421, 3464–3471 (2012)

    ADS  Google Scholar 

  94. 94

    Martizzi, D., Teyssier, R. & Moore, B. Cusp–core transformations induced by AGN feedback in the progenitors of cluster galaxies. Mon. Not. R. Astron. Soc. 432, 1947–1954 (2013)

    ADS  Google Scholar 

  95. 95

    Dutton, A. A. et al. NIHAO IX: the role of gas inflows and outflows in driving the contraction and expansion of cold dark matter haloes. Mon. Not. R. Astron. Soc. 461, 2658–2675 (2016)

    ADS  CAS  Google Scholar 

  96. 96

    Lilly, S. J. et al. Gas regulation of galaxies: the evolution of the cosmic specific star formation rate, the metallicity-mass-star-formation rate relation, and the stellar content of halos. Astrophys. J. 772, 119 (2013)

    ADS  Google Scholar 

  97. 97

    Blumenthal, G. R. et al. Contraction of dark matter galactic halos due to baryonic infall. Astrophys. J. 301, 27–34 (1986)

    ADS  CAS  Google Scholar 

  98. 98

    Binney, J. & Tremaine, S. Galactic Dynamics 2nd edn (Princeton Univ. Press, 2008)

  99. 99

    van der Kruit, P. C. & Freeman, K. C. Galaxy disks. Annu. Rev. Astron. Astrophys. 49, 301–371 (2011)

    ADS  CAS  Google Scholar 

  100. 100

    Toomre, A. On the gravitational stability of a disk of stars. Astrophys. J. 139, 1217–1238 (1964)

    ADS  Google Scholar 

  101. 101

    Merritt, D. & Sellwood, J. A. Bending instabilities in stellar systems. Astrophys. J. 425, 551–567 (1994)

    ADS  Google Scholar 

  102. 102

    Levine, E. S., Blitz, L. & Heiles, C. The vertical structure of the outer Milky Way H i disk. Astrophys. J. 643, 881–896 (2006)

    ADS  CAS  Google Scholar 

  103. 103

    Courteau, S. et al. Galaxy masses. Rev. Mod. Phys. 86, 47–119 (2014)

    ADS  Google Scholar 

  104. 104

    Genel, S. et al. Introducing the Illustris project: the evolution of galaxy populations across cosmic time. Mon. Not. R. Astron. Soc. 445, 175–200 (2014)

    ADS  CAS  Google Scholar 

  105. 105

    Schaye, J. et al. The EAGLE project: simulating the evolution and assembly of galaxies and their environments. Mon. Not. R. Astron. Soc. 446, 521–554 (2015)

    ADS  CAS  Google Scholar 

  106. 106

    Johansson, P. H., Naab, T. & Ostriker, J. P. Forming early-type galaxies in ΛCDM simulations. I. Assembly histories. Astrophys. J. 754, 115 (2012)

    ADS  Google Scholar 

  107. 107

    Anglés-Alcázar, D. et al. Cosmological zoom simulations of z = 2 galaxies: the impact of galactic outflows. Astrophys. J. 782, 84 (2014)

    ADS  Google Scholar 

  108. 108

    Governato, F. et al. Forming disc galaxies in ΛCDM simulations. Mon. Not. R. Astron. Soc. 374, 1479–1494 (2007)

    ADS  Google Scholar 

  109. 109

    Scannapieco, C. et al. The formation and survival of discs in a ΛCDM universe. Mon. Not. R. Astron. Soc. 396, 696–708 (2009)

    ADS  CAS  Google Scholar 

  110. 110

    Scannapieco, C. et al. The Aquila comparison project: the effects of feedback and numerical methods on simulations of galaxy formation. Mon. Not. R. Astron. Soc. 423, 1726–1749 (2012)

    ADS  Google Scholar 

  111. 111

    Brook, C. B. et al. Hierarchical formation of bulgeless galaxies – II. Redistribution of angular momentum via galactic fountains. Mon. Not. R. Astron. Soc. 419, 771–779 (2012)

    ADS  Google Scholar 

  112. 112

    Agertz, O., Teyssier, R. & Moore, B. The formation of disc galaxies in a ΛCDM universe. Mon. Not. R. Astron. Soc. 410, 1391–1408 (2011)

    ADS  Google Scholar 

  113. 113

    Aumer, M., White, S. D. M. & Naab, T. Towards a more realistic population of bright spiral galaxies in cosmological simulations. Mon. Not. R. Astron. Soc. 434, 3142–3164 (2013)

    ADS  Google Scholar 

  114. 114

    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)

    ADS  CAS  Google Scholar 

  115. 115

    Marinacci, F., Pakmor, R. & Springel, V. The formation of disc galaxies in high-resolution moving-mesh cosmological simulations. Mon. Not. R. Astron. Soc. 437, 1750–1775 (2014)

    ADS  Google Scholar 

  116. 116

    Übler, H. et al. Why stellar feedback promotes disc formation in simulated galaxies. Mon. Not. R. Astron. Soc. 443, 2092–2111 (2014)

    ADS  Google Scholar 

  117. 117

    Genel, S. et al. Galactic angular momentum in the Illustris simulations: feedback and the Hubble sequence. Astrophys. J. 804, L40 (2015)

    ADS  Google Scholar 

  118. 118

    Fiacconi, D., Feldmann, R. & Mayer, L. The Argo simulation – II. The early build-up of the Hubble sequence. Mon. Not. R. Astron. Soc. 446, 1957–1972 (2015)

    ADS  CAS  Google Scholar 

  119. 119

    Carollo, M. C. et al. Newly quenched galaxies as the cause for the apparent evolution in average size of the population. Astrophys. J. 773, 112 (2013)

    ADS  Google Scholar 

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We thank our colleagues at ESO-Garching and ESO-Paranal, as well as those in the 3D-HST and SINFONI/zC-SINF and KMOS/KMOS3D teams, for their support and high-quality work, which made these technically difficult observations possible. D.W. and M.F. acknowledge the support provided by DFG Projects WI 3871/1-1 and WI 3871/1-2. J.C. acknowledges the support of the Deutsche Zentrum für Luft- und Raumfahrt (DLR) via Project ID 50OR1513. T.A. and A.S. acknowledge support by the I-CORE Program of the PBC and Israel Science Foundation (Center No. 1829/12). We thank S. Lilly and A. Dekel for comments on the manuscript. This work is based on observations obtained at the Very Large Telescope (VLT) of the European Southern Observatory (ESO), Paranal, Chile (ESO programme IDs 076.A-0527, 079.A-0341, 080.A-0330, 080.A-0635, 082.A-0396, 183.A0781, 091.A-0126, 092.A-0091, 093.A-0079, 094.A-0217, 095.A-0047, 096.A-0025, 097.B-0065 and 097.A-0353).

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Drafting text, figures and Methods: R.G., N.M.F.S., H.Ü., T.N., L.J.T., O.G., D.L., A.R., R.S. and A.S.; data analysis and modelling: R.G., H.Ü., P.L., S.W. and R.D.; data acquisition and reduction: R.G., N.M.F.S., H.Ü., P.L., L.J.T., E.W., S.W., A.Be., S.B., J.C., M.F., A.G., J.T.M. and K.T.; KMOS3D and SINS/zC-SINF IFS survey design and management: N.M.F.S., R.B., E.W., C.M.C., A.R., R.S., S.T. and D.W.; 3D-HST survey analysis: N.M.F.S., S.W., G.B., I.M. and E.J.N.; theoretical interpretation: T.N., T.A., A.Bu., S.G. and O.G.

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Correspondence to R. Genzel or N. M. Förster Schreiber.

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Extended data figures and tables

Extended Data Figure 1 Location of the galaxies included in our analysis.

a, Location in stellar-mass–star-formation-rate space. The star-formation rate (SFR) is normalized to that of the ‘main sequence’37 at the redshift and stellar mass of each galaxy . b, Location in stellar-mass–size space. The size is the half-light radius measured in the observed H-band corrected to the rest-frame 5,000 Å and normalized to that of the mass–size relation for star-forming galaxies26 at the redshift and stellar mass of each source . In a and b, the greyscale image shows the distribution of the underlying galaxy population at 0.7 < z < 2.7 taken from the 3D-HST source catalogue at log(M* /M) > 9.0 and KAB < 23 mag (the magnitude cut applied when selecting KMOS3D targets and corresponding roughly to the completeness limits of the parent samples for SINS/zC-SINF targets). The current 2.5-year KMOS3D sample is shown with blue circles, and the SINS/zC-SINF sample with green diamonds. The two KMOS3D and four SINS/zC-SINF galaxies with individual outer rotation curves (RCs) are plotted as yellow circles and diamonds, respectively. Similarly, the KMOS3D and SINS/zC-SINF galaxies included in the stacked rotation curve are plotted as red circles and diamonds. All 3D-HST and KMOS3D galaxies are included in a, whereas only star-forming galaxies (SFGs) are shown in b, defined as having a specific star-formation rate higher than the inverse of the Hubble time at their redshift. The galaxies with individual outer rotation curves lie on and up to a factor of four times the main-sequence (MS) in star-formation rate (with mean and median log(SFR/SFRMS) = 0.24), and have sizes 1.2–2 times the relation (‘M–R SFGs’; mean and median offset in ). In star-formation rate and , the distribution of the stacked rotation-curve sample is essentially the same as the reference 3D-HST population in mean/median offsets (approximately 0.06 dex above the main-sequence and 0.07 dex above the mass–size relation) and in their scatter about the relationships (approximately 0.3 dex in log(SFR) and 0.17 dex in ); see refs 26, 37.

Extended Data Figure 2 Quality of fit and error of parameter determinations.

The reduced chi-squared as a function of the dark-matter fraction fDM at R1/2 for the six galaxies in our sample, once the other parameters (x0, y0, the position angle of the kinematic major axis PAmaj, i, σ0, R1/2 and B/T) are fixed at their best-fit values. Global minima are marked by circles; error bars give Δχ2 = ±4 ranges, corresponding to confidence levels of 95% (2 r.m.s.) under the assumption of single-parameter Gaussian distributions. This is the most important parameter dependence for our dataset.

Extended Data Figure 3 Mean changes in fDM and for changes in the secondary parameters B/T and R1/2, for COS 01351, D3a 6397, GS4 43501 and D3a 15504.

Changes in B/T and R1/2 are labelled ‘B/T ± 0.1’ and ‘Re ± 1σ’, respectively, where 1σ is the uncertainty on R1/2 given in Table 1; is the reduced chi-squared.

Extended Data Figure 4 Cumulative mass as a function of radius for one of our studied galaxies (GS4 43501).

Solid lines show the best fit; error bars show the variations in total (black, grey), baryonic (green) and dark-matter (DM; purple) mass at the outermost projected radius constrained by our data, if deviations from B/T and R1/2 within the uncertainties are considered (only cases with are considered). Dashed lines show the best fit for a model with lower concentration parameter (c = 2 instead of c = 5); dashed-dotted lines show the best fit for a model with adiabatic contraction (AC)97. Both modifications of the dark-matter profile lead to changes in the cumulative mass that are smaller than those obtained by varying B/T and R1/2 within the above uncertainties. The grey lines encompass variations in the dark-matter fraction of fDM(R1/2) = [0.14, 0.27] (best-fit fDM(R1/2) = 0.19).

Extended Data Figure 5 Minor axis cut at Rmajor = 0.71″ of D3a 15504.

Shown are the velocities (data points, with 1 r.m.s. error bars) and disk models for different inclinations (lines): 25° (red), 30° (blue), 40° (magenta) and 50° (green). The minor-axis cut favours a low inclination. In combination with the morphology of the stellar surface density distribution (Fig. 1) and the constraint on the baryonic mass of the disk, this yields an overall inclination of 34° ± 5° (Table 1). Rmajor is the radial distance from the centre of the galaxy along the kinematic major axis.

Extended Data Figure 6 Residual maps.

a, b, Residual maps (data minus model) for velocity (a; vdata − vmodel) and velocity dispersion (b; σdata − σmodel), for the six galaxies studied here. The colour scale is the same in all maps (from −200 km s−1 (purple) to +200 km s−1 (white)). Minimum and maximum values are noted in each map, as are the median and median dispersion (‘disp’) values.

Supplementary information

Supplementary Discussion

This file contains a comparison of the results to state-of-the-art cosmological simulations of galaxy formation, and a brief comment on the connection to the ‘thick disk’-phenomenon in local spiral galaxies. (PDF 145 kb)

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Genzel, R., Schreiber, N., Übler, H. et al. Strongly baryon-dominated disk galaxies at the peak of galaxy formation ten billion years ago. Nature 543, 397–401 (2017).

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