Volume 586, February 2016
|Number of page(s)||22|
|Published online||26 January 2016|
Weak-lensing-inferred scaling relations of galaxy clusters in the RCS2: mass-richness, mass-concentration, mass-bias, and more
1 Argelander-Institut für Astronomie, Auf dem Hügel 71, 53121 Bonn, Germany
2 Leiden Observatory, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands
3 University College London, Gower Street, London WC1E 6BT, UK
4 South African Astronomical Observatory, PO Box 9, 7935 Observatory, South Africa
5 The Department of Astronomy and Astrophysics, and the Kavli Institute for Cosmological Physics, The University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637, USA
6 Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, Ontario, M5S 3H4, Canada
Received: 11 June 2015
Accepted: 12 October 2015
We study a sample of ~104 galaxy clusters in the redshift range 0.2 <z< 0.8 with masses M200 > 5×1013 h70-1 M⊙, discovered in the second Red-sequence Cluster Survey (RCS2). The depth and excellent image quality of the RCS2 enabled us to detect the cluster-mass cross-correlation up to z ~ 0.7. To obtain cluster masses, concentrations, and halo biases, we fit a cluster halo model simultaneously to the lensing signal and to the projected density profile of red-sequence cluster members, because the latter provides tight constraints on the cluster miscentring distribution. We parametrised the mass-richness relation as M200 = A × (N200/ 20)α and find A =(15.0±0.8)×1013 h70-1 M⊙ and α = 0.73 ± 0.07 at low redshift (0.2 < z < 0.35). At intermediate redshift (0.35 < z < 0.55), we find a higher normalisation, which points towards a fractional increase in the richness towards lower redshift caused by the build-up of the red sequence. The miscentring distribution is well constrained. Only ~30% of our BCGs coincide with the peak of the dark matter distribution. The distribution of the remaining BCGs are modelled with a 2D-Gaussian, whose width increases from 0.2 to 0.4 h70-1 Mpc towards higher masses. The ratio of width and r200 is constant with mass and has an average value of 0.44 ± 0.01. The mass-concentration and mass-bias relations agree fairly well with literature results at low redshift, but have a higher normalisation at higher redshifts, possibly because of selection and projection effects. The concentration of the satellite distribution decreases with mass and is correlated to the concentration of the halo.
Key words: gravitational lensing: weak / galaxies: clusters: general
© ESO, 2016
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