Full strength of (weak) Cluster lensing Elinor Medezinski Tel Aviv University Medezinski et al. 2007, Broadhurst et al. 2008, Medezinski et al. 2009, Medezinski et al. 2010 (in prep) Advisors: Tom Broadhurst, Yoel Rephaeli Collaborators: Keiichi Umetsu, Narciso Benitez, Dan Coe, Holland Ford, Masamune Oguri
Color-magnitude, A1689 (Medezinski et al. 2007) E/SO sequence galaxies Three galaxy samples Red – background. (redder than sequence) Blue – faint background. (determine by comparing WL signal to red) Green – cluster +background Set magnitude limit to 26.5 to avoid incompleteness (Medezinski et al. 2007) Red Blue
New approach - Color-Color B,R,z’ for A370 V,R,z’ for RXJ1347 g’,r’,i’ for A1703 (Medezinski et al. 2009) Galaxy number density map 4 Density peaks – different galaxy populations A370
Average radius in Color-Color space Color code = distance from cluster center Blue = low mean radius – cluster galaxies A370
Sample selection in Color-Color Red – background Blue – background Green – cluster +~background Pink – foreground +background
Weak lensing profiles “Dilution” method gT profiles – rising background signal ~zero for green – diluted by unlensed cluster members A370 Red – background Blue – background Green – cluster +~background Pink – foreground +background Weak lensing measured using IMCAT (Umetsu & Broadhurst 2008, Umetsu, Medezinski et al. 2010) “Dilution” method Cluster membership – almost ~100% for entire radius range, →green sample is comprised mostly of cluster.
Foreground contamination Density profiles – foreground shows homogeneous distribution, like background, unlike cluster which is concentrated. A370 Red – background Blue – background Green – cluster +~background Pink – foreground +background gT profiles – foreground also shows diluted signal relative to background
Dilution in other work Oguri et al. 2009 Diluted by a factor of ~2 in the center Leads to underestimated Einstein radius Leads to underestimated Cvir A1703
2D Mass reconstruction + Round, ~relaxed massive clusters Weak-lensing galaxy # density Round, ~relaxed massive clusters Broadhurst et al. 2008
NFW fits give high concentrations (Cvir=rvir/rs) Broadhurst et al. 2008 gT-profiles agree NFW fits give high concentrations (Cvir=rvir/rs) than expected by ΛCDM N-body simulations Use magnification to check consistency of gT results
NFW parameters Cvir-Mvir comparison with other studies and ΛCDM 4σ discrepancy with ΛCDM, even considering orientation and selection bias (Hennawi et al 2007, Oguri & Blanford et al. 2009)
Luminosity & M/L profiles A1689 A1703 A370 RXJ1347-11 Cluster luminosity – “g-weighted” flux to get cluster flux Flux Luminosity Linear fit M/L goes down in the outskirts – morphology-density related effect (Dressler 1980)
M/L profiles M/L goes down in the center – luminous BCGs M/L goes down in the outskirts –morphology-density relation (Dressler 1980) A1689 A1703 A370 RXJ1347-11
Cluster Luminosity Function – A1689 Flat faint-end, no upturn
Lensing distance vs. redshift: Weak lensing strength vs. redshift test of cosmology using WL distortions (Medezinski et al. 2010 in prep) In the weak limit, Lensing distance vs. redshift:
Weak lensing samples Select background galaxy samples –”red”, “blue”, “green” and “dropouts” and measure their lensing profile Red – background Blue – background Green – background Pink – background (high-z dropouts) A370
Fit background WL distortion profile with power law: Bright Red – background Blue – background Green – background Pink – background (high-z dropouts) Fit background WL distortion profile with power law: Find amplitude ai for other samples, with same power law Faint
COSMOS Redshifts 30-band wide field (2 sq. deg.) survey (Capak et al. 2007) Photometric redshifts catalog (Ilbert et al. 2009) mean redshift in color-color space Same selection samples
Results: Faint Bright gT amplitude vs. redshift overlaid on the lensing distance – redshift curves A370 ZwCl0024-17 RXJ1347-11
Summary Developed new scheme to resolve cluster/foreground/background selected in color-color space and better determine weak lensing profiles. Determined light profiles & radial luminosity functions of A1689, A1703, A370, RXJ1347 reliably, with no need to resolve the cluster sequence based on color. Found flat luminosity function, with no need for far-field counts for background subtraction. Constructed M/L profiles to the virial radius, showing physical behavior of DM to light distributions, dropping to the center of cluster, and also dropping to the outskirts. Deduced high NFW concentrations, contradicting ΛCDM simulation expectation values. Use weak lensing distortions to constrain the lensing distance – redshift relation. Future work: Obtain photo-z’s using more colors for consistency checks. Extend to other clusters (CL0024 submitted Umetsu et al. 2009, MACS sample) using existing Subaru. Combine w/ strong-lensing from HST/ACS (Zitrin et al. 2009) – Hubble MCT proposal accepted!! – 25 clusters with 525 orbits. Constrain mass distribution by combining X-ray and SZ from Chandra and Amiba (Amiba paper - Umetsu et al. 2009).