Ludovic Van WaerbekeDepartment of Physics and Astronomy

University of British Columbia

Statistical lensing in COSMOS

With:

F. Bernardeau (CEA)Y. Mellier (IAP)E. Semboloni (IAP)& the COSMOS team

Weak lensing two-points Weak lensing two-points statistics: What is measured?statistics: What is measured?

Mass power spectrum Mass power spectrum normalisationnormalisation

Slope of the power spectrumSlope of the power spectrum

Mean density parameterMean density parameter

Redshift of the sourcesRedshift of the sources

<<>>~~zzss

1.4 1.4 -(-(nn+2)/2+2)/2

Contaldi et al. 2004

VIRMOSI~24Z~0.9LVW et al.

COSMOS should reach ~ same accuracy with two major differences:-followups. In particular photoz enables lenses selection, 3D lensing, etc…-morphology-depth enables high order statistics despite small FOV.

redshift distributions based on the Hubble deep fields

25.<i<27.Zphot~1.4

Cycle 12 area Polygon masks (ds9 format) are available

PSF anisotropy pattern averaged over cycle 12 chips

Preliminary E and B modes aperture mass

LCDM model with 8=0.8 and zS~1.4

~30 stars per chip

Needs image reprocessing with smaller pixel size?

Star-gal shear aperture correlation

Star-gal shear correlation function

Strong lensing with R. Gavazzi (OMP, Toulouse)

Singular ISZlens~0.4Zsource~3Re=1.58”

M~4.4x1011 Mo h70-1

Inverse pixel mapping into the source plane