Center for Cosmology and Astro-Particle Physics Great Lakes Cosmology Workshop VIII, June, 1-3, 2007...

Center for Cosmology and Astro-Particle Physics

Great Lakes Cosmology Workshop VIII, June, 1-3, 2007

Probing Dark Energy with Cluster-Galaxy Weak Lensing

JAIYUL YOO AND DAVID WEINBERG

DEPARTMENT OF ASTRONOMY, THE OHIO STATE UNIVERSITY

• cluster-matter cross correlation (profile & bias)

• stacking rank-ordered clusters: monotonic relation of the mean mass-observable no mass estimate of individual clusters no accurate relation to true cluster mass

• weak lensing of the stacked sample of clusters

Cluster-Galaxy Weak Lensing

PROBING DARK ENERGY WITH CLUSTER-GALAXY WEAK LENSING

Why Robust?

• stacked sample


Why Robust?

• stacked sample ≅ mass-ordered

clusters


Why Robust?

• stacked sample ≅ mass-ordered

clusters

• works for arbitrary relation and bias


Cosmological Probe?• stacked sample is

set by cosmology!

• growth factor, volume, halo mass function (given number of clusters)

• constituent clusters are also different!


Prediction and Observable


angular diameter distance

critical surface density

• clusters provide high S/N (vs cosmic shear)

• spherical symmetric dark matter halo

• apparent lens center (central cD galaxies)

• stacking increases S/N → high redshift clusters

• tangential shear profile

Why Better?

• clusters provide high S/N (vs cosmic shear)

• spherical symmetric dark matter halo

• apparent lens center (central cD galaxies)

• stacking increases S/N → high redshift clusters

• tangential shear profile


Parameter Sensitivity


28.0m24.0m20.0m

Parameter Sensitivity


Dark Energy Constraint


• DES type survey

• 1,2,3 σ contours

• no CMB priors

• flat universe

Conclusion and Prospects

• novel method of cluster-galaxy weak lensing works for arbitrary mass-observables robust to scatter and bias

• readily applicable, strong constraints

• application to OSU Dark Energy Survey with Large Binocular Telescope (LBT)


Stay “fine” tuned!!!

Center for Cosmology and Astro-Particle Physics Great Lakes Cosmology Workshop VIII, June, 1-3, 2007...

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