LoCuSS: The near-infrared luminosity and weak-lensing mass scaling relation of galaxy clusters

Sarah L. Mulroy, Graham P. Smith, Chris P. Haines, Daniel P. Marrone, Nobuhiro Okabe, Maria J. Pereira, Eiichi Egami, Arif Babul, Alexis Finoguenov, Rossella Martino

Research output: Contribution to journalArticlepeer-review

15 Scopus citations


We present the first scaling relation between weak-lensing galaxy cluster mass, MWL, and near-infrared luminosity, LK. Our results are based on 17 clusters observed with wide-field instruments on Subaru, the United Kingdom Infrared Telescope, the Mayall Telescope, and the MMT. We concentrate on the relation between projected 2D weak-lensing mass and spectroscopically confirmed luminosity within 1 Mpc, modelled as MWL∞Lbk, obtaining a power-law slope of b = 0.83+0.27-0.24 and an intrinsic scatter of σ lnMWL |LK =10+8-5 percent. Intrinsic scatter of ∼ 10 percent is a consistent feature of our results regardless of how we modify our approach to measuring the relationship between mass and light. For example, deprojecting the mass and measuring both quantities within r500, that is itself obtained from the lensing analysis, yields σlnMWL|LK=10+7-5 percent and b=0.97+0.17-0.17. We also find that selecting members based on their (J - K) colours instead of spectroscopic redshifts neither increases the scatter nor modifies the slope. Overall our results indicate that near-infrared luminosity measured on scales comparable with r500 (typically 1Mpc for our sample) is a low scatter and relatively inexpensive proxy for weak-lensing mass. Near-infrared luminosity may therefore be a useful mass proxy for cluster cosmology experiments.

Original languageEnglish (US)
Pages (from-to)3309-3317
Number of pages9
JournalMonthly Notices of the Royal Astronomical Society
Issue number4
StatePublished - Oct 1 2014


  • Cosmology: observations
  • Galaxies: stellar content
  • Gravitational lensing: weak
  • Infrared: galaxies

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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