CFHTLenS: co-evolution of galaxies and their dark matter haloes

Michael J. Hudson, Bryan Gillis, Jean Coupon, Hendrik Hildebrandt, Thomas Erben, Catherine Heymans, Henk Hoekstra, Thomas D. Kitching, Yannick Mellier, Lance Miller, Ludovic Van Waerbeke, Christopher Bonnett, Liping Fu, Konrad Kuijken, Barnaby Rowe, Tim Schrabback, Elisabetta Semboloni, Edo van Uitert, Malin Velander

Research output: Contribution to journalArticlepeer-review

Abstract

Galaxy-galaxy weak lensing is a direct probe of the mean matter distribution around galaxies. The depth and sky coverage of the Canada-France-Hawaii Telescope Legacy Survey yield statistically significant galaxy halo mass measurements over a much wider range of stellar masses (10(8.75) to 10(11.3) M-circle dot) and redshifts (0.2 <z <0.8) than previous weak lensing studies. At redshift z similar to 0.5, the stellar-to-halo mass ratio (SHMR) reaches a maximum of 4.0 +/- 0.2 per cent as a function of halo mass at similar to 10(12.25) M-circle dot. We find, for the first time from weak lensing alone, evidence for significant evolution in the SHMR: the peak ratio falls as a function of cosmic time from 4.5 +/- 0.3 per cent at z similar to 0.7 to 3.4 +/- 0.2 per cent at z similar to 0.3, and shifts to lower stellar mass haloes. These evolutionary trends are dominated by red galaxies, and are consistent with a model in which the stellar mass above which star formation is quenched 'downsizes' with cosmic time. In contrast, the SHMR of blue, star-forming galaxies is well fitted by a power law that does not evolve with time. This suggests that blue galaxies form stars at a rate that is balanced with their dark matter accretion in such a way that they evolve along the SHMR locus. The redshift dependence of the SHMR can be used to constrain the evolution of the galaxy population over cosmic time.

Original languageEnglish
Pages (from-to)298-314
Number of pages17
JournalMonthly Notices of the Royal Astronomical Society
Volume447
Issue number1
DOIs
Publication statusPublished - 11 Feb 2015

Keywords

  • gravitational lensing: weak
  • galaxies: haloes
  • cosmology: observations
  • dark matter
  • TELESCOPE LENSING SURVEY
  • STELLAR MASS FUNCTION
  • STAR-FORMING GALAXIES
  • SHAPE MEASUREMENT
  • OCCUPATION DISTRIBUTION
  • LAMBDA-CDM
  • REDSHIFT
  • LUMINOSITY
  • EVOLUTION
  • SIMULATIONS

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