Paul Schechter (MIT)

Searching for quadruply lensed quasars with DES, Gaia, LSST and Euclid
When Oct 22, 2020 from 02:30 PM to 03:30 PM
What
  • Colloquium
Where Cyberspace
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Quadruply lensed quasars are beautiful.  They are also powerful tools for studying cosmology, the structure of lensed quasars and the stellar content of lensing galaxies, but only if one can first find them.  To date the Dark Energy Survey and Gaia have approximately doubled the number of known quads, to roughly 50.  LSST and Euclid will allow a tenfold or greater increase.  While some quads can be found using only catalogued sources, others require a return to the original pixels for more aggressive analysis.  Two issues are discussed in detail: 1) extreme deblending and 2) the four (or two) points where an ellipse intersects a hyperbola that passes through its center.