(Proposal ID) S16A-032

(PI) Futamase, Toshifumi

(Proposal Title)
Systematic Weak-lensing Study of Subhalos in Very Nearby Galaxy Clusters IV

(Abstract)
To complete our scientific goals approved in S14B, S15A and S15B, we pursue our
 systematic weak-lensing study of very nearby massive galaxy clusters in the 
redshift range of 0.02 and 0.06, of which large apparent size enables us to 
directly measure subhalos' masses. The extremely large field-of-view of HSC is 
the unique instrument to cover the entire region of the very nearby clusters 
by one pointing. We propose to observe remaining clusters which will be 
efficiently observed in this semester. We aim (1) to measure global mass 
distribution of very nearby massive clusters, (2) to measure masses of 
cluster subhalos with different selection functions such as shear-selected 
and luminosity-selected, (3) to compare the distributions among subhalos, 
galaxies, X-ray emitting gas, the smooth mass component of the main cluster, 
(4) to conduct the statistical study about subhalo properties such as mass 
function and radial distribution, in a comparison with N-body simulations, 
and (5) to investigate the correlation between subhalo properties and the main 
cluster mass. These information provide not only a stringent test of CDM on 
sub-cluster scales but also the lower bound of the dark matter mass. Queue 
observation enables us to collect full data of the remaining sample of 
clusters.