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Astronomy Colloquium
"Looking at the Universe through gravitational lenses"
Date: Thursday, February 18th
Time: 3:30 pm
Place: Zoom meeting(see Abstract ) Coffee and tea 3:30pm, Talk 3:45pm
Speaker: Lindsay King, University of Texas-Dallas
Abstract: Massive objects distort space-time, acting as gravitational lenses and distorting light bundles traveling to us from distant sources. Distinctive lensing signatures, including multiple or slightly stretched images of distant galaxies, are seen on the electromagnetic (EM) sky. Most of the matter in the Universe is dark; importantly, these lensing signatures allow us to map and weigh matter in massive objects, irrespective of whether it is luminous or dark. We start with an overview of the principles of lensing, some of the signatures seen on the EM sky on different scales in the Universe, and some of the conclusions that resulted.

One example that we will discuss is our investigation of the dark and luminous matter in a rare and extremely energetic collision between two giant clusters of galaxies, using lensing and other astrophysical data.

Theoretical work has shown that gravitational waves (GW) are also gravitationally lensed. We briefly describe the expected impact of lensing on the GW sky that will be seen with the future LISA space-based detector, and our current research on this topic.
Web Link:
https://uwmadison.zoom.us/j/88513896776?pwd=Y1JtRE1KZllxWkFTamJBSGtGdm9yQT09
Host: Tae Sun Kim UW Astronomy Department
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