CFHTLenS: the relation between galaxy dark matter haloes and baryons from weak gravitational lensing

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

Research output: Contribution to journalArticlepeer-review

Abstract

We present a study of the relation between dark matter halo mass and the baryonic content of their host galaxies, quantified through galaxy luminosity and stellar mass. Our investigation uses 154 deg2 of Canada–France–Hawaii Telescope Lensing Survey (CFHTLenS) lensing and photometric data, obtained from the CFHT Legacy Survey. To interpret the weak lensing signal around our galaxies, we employ a galaxy–galaxy lensing halo model which allows us to constrain the halo mass and the satellite fraction. Our analysis is limited to lenses at redshifts between 0.2 and 0.4, split into a red and a blue sample. We express the relationship between dark matter halo mass and baryonic observable as a power law with pivot points of 1011h−270L and 2×1011h−270M for luminosity and stellar mass, respectively. For the luminosity–halo mass relation, we find a slope of 1.32 ± 0.06 and a normalization of 1.19+0.06−0.07×1013h−170M for red galaxies, while for blue galaxies the best-fitting slope is 1.09+0.20−0.13 and the normalization is 0.18+0.04−0.05×1013h−170M⊙⁠. Similarly, we find a best-fitting slope of 1.36+0.06−0.07 and a normalization of 1.43+0.11−0.08×1013h−170M for the stellar mass–halo mass relation of red galaxies, while for blue galaxies the corresponding values are 0.98+0.08−0.07 and 0.84+0.20−0.16×1013h−170M⁠. All numbers convey the 68 per cent confidence limit. For red lenses, the fraction which are satellites inside a larger halo tends to decrease with luminosity and stellar mass, with the sample being nearly all satellites for a stellar mass of 2×109h−270M⁠. The satellite fractions are generally close to zero for blue lenses, irrespective of luminosity or stellar mass. This, together with the shallower relation between halo mass and baryonic tracer, is a direct confirmation from galaxy–galaxy lensing that blue galaxies reside in less clustered environments than red galaxies. We also find that the halo model, while matching the lensing signal around red lenses well, is prone to overpredicting the large-scale signal for faint and less massive blue lenses. This could be a further indication that these galaxies tend to be more isolated than assumed.

Original languageEnglish
Pages (from-to)2111-2136
Number of pages26
JournalMonthly Notices of the Royal Astronomical Society
Volume437
Issue number3
Early online date30 Nov 2013
DOIs
Publication statusPublished - 21 Jan 2014

Keywords

  • gravitational lensing: weak
  • galaxies: haloes
  • cosmology: observations
  • dark matter
  • DIGITAL SKY SURVEY
  • VLT DEEP SURVEY
  • SPECTROSCOPIC TARGET SELECTION
  • SPACE-TELESCOPE OBSERVATIONS
  • TULLY-FISHER RELATION
  • LARGE-SCALE STRUCTURE
  • STAR-FORMATION RATES
  • STELLAR MASS
  • PHOTOMETRIC REDSHIFTS
  • FORMATION HISTORIES

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