Oral Presentation

Constraining the Richness-to-Mass Relation of CAMIRA Clusters using the Lensing Effect of Magnification Bias in the Hyper Suprime-Cam Survey

Author(s): I-Non Chiu (ASIAA), Keiichi Umetsu (ASIAA) and the WLWG of the HSC collaboration

Presenter: I-Non Chiu (ASIAA)

The team of the HSC survey is carrying out the multi-band (grizY) imaging over the area of 1400 deg2 with the 8.2m Subaru Telescope.
The unprecedentedly deep (5 sigma limiting magnitude of a 2 arcsec diameter aperture: i~26 mag) imaging uniformly over a large area with the excellent seeing (median seeing of 0.6 arcsec in the i-band) will deliver the breakthrough science to the community, especially in the current era prior to the LSST.
In this work, we present the lensing measurements of the magnification bias effect around the optically selected galaxy clusters out to redshift z ~ 1 in the coverage of ~380 deg2 in the HSC survey.
We then utilize these lensing magnification measurements to calibrate the richness to mass scaling relation of galaxy clusters.
The background sources are selected in the color-color space with the goal of sampling the background galaxies at redshift z ~ 1.5.
The lensing magnification of the background sample is measured by stacking over 3000 clusters in different richness and redshift bins.
We carefully quantify the contamination and the masking effect due to cluster members, and correct them in the joint modelling in a Bayesian framework.
The observed lensing signal is also verified by performing the null test on another flux-limited background sample.
This work demonstrates an important and independent method in calibrating the cluster mass independently of the shear-based analysis.