Physics - Astrophysics, Gravitation, and Cosmology Seminar

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Astrophysics, Gravitation and Cosmology Seminar - " Rare Views of Galaxy Cluster Laboratories"

Event Type
Department of Physics
464 Loomis Lab
Apr 17, 2019   12:00 pm  
Brenda Frye, University of Arizona
Betsy Greifenkamp

Galaxy clusters as astronomical tools generally offer two advantages: to boost the brightnesses of objects in the background, and to study the dark matter in the lens.  We can now introduce a third use: to unveil properties of the underlying dark matter by the detection of caustic crossing events which can yield magnification factors of 10,000 or more.  We review the approach to detect a new set of massive objects such as galaxy clusters by their rest-frame far-infrared colors (and not by the Sunyaev-Z'eldovich effect).  We move on to present Hubble Space Telescope WFC3-IR imaging in the fields of six classical giant arcs discovered using a combination of Planck and Herschel space facilities.  We construct lensing models from the many examples of image multiplicities, and compare our results with galaxy over-densities identified by more conventional methods.  We conclude with a discussion on the emerging field of caustic crossings.

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