AAS 203rd Meeting, January 2004
Session 120 Gravitational Lensing
Poster, Thursday, January 8, 2004, 9:20am-4:00pm, Hanover Hall

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[120.06] Observation of cluster substructure using higher order weakly lensed moments.

J. Irwin, M. V. Shmakova (SLAC)

Since dark matter clusters and groups may have substructure, we have examined the sextupole content of Hubble images looking for a curvature signature in background galaxies that would arise from small impact parameter galaxy-clump lensing. We describe techniques for extracting and analyzing sextupole and higher weakly lensed moments. Indications of substructure, via spatial clumping of curved background galaxies, were observed in the Hubble deep fields. We will present here the results of this analysis for overlapping GOODS fields. The dark cluster and clump masses are estimated. Alternatives to a lensing hypothesis appear improbable. Observation of sextupole moments would provide a means to measure dark matter structure on smaller length scales than heretofore.

The author(s) of this abstract have provided an email address for comments about the abstract: irwin@slac.stanford.edu

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Bulletin of the American Astronomical Society, 35#5
© 2003. The American Astronomical Soceity.