Full strength of (weak) Cluster lensing Elinor Medezinski Tel Aviv University Advisors: Tom Broadhurst, Yoel Rephaeli Collaborators: Keiichi Umetsu, Narciso Benitez, Dan Coe, Holland Ford, Masamune Oguri Medezinski et al. 2007, Broadhurst et al. 2008, Medezinski et al. 2009, Medezinski et al. 2010 (in prep)
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 A370
Weak lensing profiles • 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.
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
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)
Weak lensing strength vs. redshifttest 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
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
Faint Bright Results: • 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).