Foreground Physical Effects on
LSST Weak Lensing Science:
A Workshop on the Impact of the Last Kiloparsec

The Workshop was held at the UC Davis Conference Center, which is right next door to the Hyatt Place UC Davis.  Directions to Davis are here. 

This workshop was supported by the LSST Corporation Enabling Science program.

To achieve the ultimate sensitivity of the LSST to weak lensing (WL) science, we must understand in great detail physical effects in the “last kiloparsec” of a photon’s journey.  WL science places stringent requirements on our ability to accurately measure galaxy shapes and redshifts, which in turn demands precise and accurate knowledge of the point spread function, astrometry, and photometry. These measurements are influenced by the interaction of light with Galactic dust, the Earth’s atmosphere, the telescope optics, and the CCD sensors. The LSST Project is developing mechanisms for correcting for systematic effects, once known. We plan a two-day workshop to focus expertise in these areas on assessing our current understanding of these physical effects and to address the following questions:

• What currently limits our understanding of important foregrounds in the last kiloparsec?
• How well must we understand each physical effect so that residual biases do not limit WL science with the LSST, given the unprecedented statistical precision?
• Can current simulation efforts be augmented to improve our understanding of these effects?
• What data could we take now or during LSST commissioning to improve and test our understanding?

See Workshop Agenda for the program, and Deliverables for outcomes summary.