NOAO >   Observing Info >   Approved Programs >   2006A-0546

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Proposal Information for 2006A-0546


PI: Joseph Hennawi, UC Berkeley, joeh@berkeley.edu
Address: Astronomy Department, 601 Campbell Hall, Berkeley, CA 94720-3411, United States

CoI: Mike Gladders, Carnegie
CoI: Neal Dalal, CITA
CoI: Priya Natarajan, Yale
CoI: Masamune Oguri, Princeton
CoI: Michael Strauss, Princeton

Title: WIYN Imaging and GMOS Spectroscopy of Giant Arcs Behind the Strongest Lenses in the Universe

Abstract: We propose to exploit the excellent image quality delivered by the WIYN to search for strongly gravitationally lensed arcs behind the richest clusters discovered in the ~ 8000 deg^2 of the Sloan Digital Sky Survey (SDSS) photometric catalog, an area 20 times larger than any previous giant arc search. The SDSS cluster catalog is complete out to z~ 0.6 for the richest systems, and is the largest cluster catalog in existence. Our deep imaging of the ~ 100 richest clusters in some of this Gpc^3 cosmological volume has already revealed 15 new lensing clusters, including two with multiple sets of multiply imaged arcs, similar to Abell 2218 and CL0024+1654. We propose to complete this search this coming semester. We also request 6.5 hours of GMOS North spectroscopy to determine redshifts of the arcs in our two most dramatic lensing clusters, which are crucial for constructing models of the dark matter distributions and are complementary to future HST imaging of these clusters. The improved statistics and well-defined selection of our lensing cluster sample will transform cluster strong lensing from the study of a handful of rare systems, into a powerful tool to study the densest concentrations of dark matter in the Universe.


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



NOAO >   Observing Info >   Approved Programs >   2006A-0546

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