Full strength of (weak) Full strength of (weak) Cluster lensingCluster lensing

Advisors: Tom Broadhurst, Yoel RephaeliCollaborators: Keiichi Umetsu, Narciso Benitez, Dan Coe,

Holland Ford, Masamune Oguri, Andy Taylor

Granada CLASH team meeting, Sep 21st, 2010

Medezinski et al. 2007, Medezinski et al. 2010a, Medezinski et al. 2010b (submitted)

Elinor MedezinskiElinor MedezinskiTel Aviv UniversityTel Aviv University

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Subaru data reductionSubaru data reductionFor each filter of each cluster • use Subaru pipeline:

– Renaming – Overscan and bias subtraction – Making flat frames– Flat fielding– Distortion and atmospheric dispersion correction– PSF size measurement– PSF size equalization– Sky subtraction– Masking out AG probe– Masking out bad regions– Alignment– Co-adding

• Derive zeropoints

• Catalog making: SExtractor (ColorPro) + imcat shapes (KSB)

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Subaru Cluster Dataset StatusSubaru Cluster Dataset Status• 8.5 clusters done

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Weak Lensing DilutionWeak Lensing Dilution

• Oguri et al. 2009

• Diluted by a factor of ~2 in the center

• Leads to underestimated Einstein radius

• Leads to underestimated Cvir

A1703

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Weak lensing profilesWeak lensing profilesA370• gT profiles –

•rising background signal

•~zero for green – diluted by unlensed cluster members

• Cluster membership – almost ~100% for entire radius range,

→green sample is comprised mostly of cluster.

G

B

Green

clcl D

D

Backg

Greeng

N

Nf

1““Dilution” Dilution” methodmethod

• Red – background• Blue – background• Green – cluster

+~background• Pink – foreground

+background

Weak lensing measured using IMCAT (Umetsu & Broadhurst 2008, Umetsu, Medezinski et al. 2010)

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Setting limitsSetting limits

• Distortion reduces closer to the cluster sequence

Red sample lower limitBlue sample upper limit

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Luminosity & M/L profilesLuminosity & M/L profiles

• 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)

rg

gFFrF

Bi

Gi

Gi

i

Gicl

)(

•A1689

*A1703

A370

♦RXJ1347-11

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Weak lensing samplesWeak lensing samples• Select background galaxy samples – “orange”, “green” ”red”,

“blue”, and “dropouts” and measure their lensing profile

A370• Grey – foreground• Orange – background• Green – background• Red – background• Blue – background• Pink – background

(high-z dropouts)

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• Fit background WL distortion profile with power law:

• Find amplitude ai for other samples, with same power law

Bright

Faint

• Grey – foreground• Orange – background• Green – background• Red – background• Blue – background• Pink – background

(high-z dropouts)

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COSMOS RedshiftsCOSMOS Redshifts

• 30-band wide field (2 sq. deg.) survey (Capak et al. 2007)

• Photometric redshifts catalog (Ilbert et al. 2009)

• Same selection samples• mean redshift in color-

color space

• Grey – foreground• Orange – background• Green – background• Red – background• Blue – background• Pink – background

(high-z dropouts)

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Samples photo-z distributionsSamples photo-z distributions

• Separated redshift bins

• Selection in different field

• Grey – foreground• Orange – background• Green – background• Red – background• Blue – background• Pink – background

(high-z dropouts)

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COSMOS vs. GOODSCOSMOS vs. GOODS

• General agreement

• Low-z peak mostly erroneous

• Examine low-z contamination vs. color limit to make cuts

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WL and redshift vs. magnitudeWL and redshift vs. magnitude

• Red increases as expected

• Blue decreases – sign of shape underestimation at faint mags

• Dds/Ds agrees – cannot determine redshifts accurately beyond z’~25 • Grey – foreground

• Orange – background• Green – background• Red – background• Blue – background• Pink – background

(high-z dropouts)

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• gT amplitude vs. redshift overlaid on the lensing distance – redshift curves

• Using 25 A370’s - Δw≈0.6

RXJ1347-11

A370

ZwCl0024-17

Faint

Bright

Results:Results:

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SummarySummary• 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 determine the lensing distance – redshift relation, and thereby constraining cosmological parameters – Δw≈0.6.

Recent & Future work:

• Obtain photo-z’s using more colors for consistency checks.

• Determine methods uncertainties due to shapes, redshifts, sample selection etc w/ simulations.

• Combine w/ strong-lensing from MCT/CLASH.

• Constrain mass distribution by combining X-ray (Lemze et al. 2008) and SZ (Umetsu et al. 2009).