The dusty, albeit ultraviolet bright, infancy of galaxies

J. Devriendt, C. Rimes, C. Pichon, R. Teyssier, D. Le Borgne, D. Aubert, E. Audit, S. Colombi, S. Courty, Y. Dubois, S. Prunet, Y. Rasera, A. Slyz, D. Tweed

Research output: Contribution to journalLetterpeer-review

27 Scopus citations


The largest galaxies acquire their mass early on, when the Universe is still youthful. Cold streams violently feed these young galaxies a vast amount of fresh gas, resulting in very efficient star formation. Using a well resolved hydrodynamical simulation of galaxy formation, we demonstrate that these mammoth galaxies are already in place a couple of billion years after the big bang. Contrary to local star-forming galaxies, where dust re-emits a large part of the stellar ultraviolet (UV) light at infrared and sub-millimetre wavelengths, our self-consistent modelling of dust extinction predicts that a substantial fraction of UV photons should escape from primordial galaxies. Such a model allows us to compute reliably the number of high-redshift objects as a function of luminosity, and yields galaxies whose UV luminosities closely match those measured in the deepest observational surveys available. This agreement is remarkably good considering our admittedly still simple modelling of the interstellar medium physics. The luminosity functions of virtual UV luminous galaxies coincide with the existing data over the whole redshift range from 4 to 7, provided cosmological parameters are set to their currently favoured values. Despite their considerable emission at short wavelengths, we anticipate that the counterparts of the brightest UV galaxies will be detected by future sub-millimetre facilities like ALMA.

Original languageEnglish (US)
Pages (from-to)L84-L88
JournalMonthly Notices of the Royal Astronomical Society: Letters
Issue number1
StatePublished - Mar 2010
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


  • Galaxies: evolution
  • Galaxies: formation
  • Galaxies: high-redshift
  • Galaxies: luminosity function, mass function


Dive into the research topics of 'The dusty, albeit ultraviolet bright, infancy of galaxies'. Together they form a unique fingerprint.

Cite this