Day 855

Tuesday.


1503.0614
Emulating the CFHTLenS weak lensing data: cosmological constraints from moments and Minkowski functionals
Petri, Liu, Haiman, May, Hui, Kratochvil

Non-Gaussian features containing the majority of the information in WL.  Examine constraints on the parameter triplet (Omega_m, w, sigma8) from non-G features of the WL kappa field, including a set of moments (up to 4th order) and Minkowski functionals, using publicly available data from CFHTLenS.  Utilize a suite of ray-tracing N-body sims spanning 91 points, replicating the galaxy sky positions, z and shape noise in the CFHTLenS catalogs.  Then build an emulator that interpolates the simulated descriptors as a function of (O,w,s) and use it to compute the likelihood function and parameter constraints.  Employ a PCA to reduce dimensionality and to help stabilize the constraints with respect to the number of bins upside to construct each statistic.  Using the full set of statistics, find Sigma8=sigma8(O/0.27)^0.55=0.75±0.04 (68%CL), in agreement with previous values.  Find that constraints on the (O,s) doublet from the Minkowski functionals suffer a strong bias.  However, high-order moments break the (O,s) degeneracy and provide a tight constraint on these parameters with no apparent bias.  The main contribution comes from quartic moments of derivatives.


1503.06373
Detection of a filament connected to CL0016 with weak gravitational lensing
Higuchi, Oguri, Tanka, Sakurai

Report on the WL detection of a filament between two clusters at z=0.55.  Conduct WL analysis of multi-band Suprime-cam images with lensfit.  The WL signals from the filament are contaminated by signals from the adjacent massive clusters and statistically subtract the cluster component using two different methods.  Both methods yield consistent shear profiles on the filament with >2sigma sig and the average surface mass density of the filament is 3.2±0.1 e14 h Msun / Mpc^2, which is in broad agreement with previous studies.  On-going surveys such as HSC will identify more filaments, which will serve as a new probe of structure formation in the Universe.