JPL Home NASA Home Caltech Home
Follow this link to skip to the main content
NASA Logo - Jet Propulsion Laboratory
JPL Home Earth Solar System Stars & Galaxies Technology
Science Visitor and Colloquium Program
Information for Visiting Speakers
Astrophysics Colloquium

The Appeal and Chore of Wide-field Surveys
Presented by Peter Melchior
Ohio State University

Thursday, July 9, 2015
4:00 P.M. in 169-336

Several current and forthcoming optical/infrared wide-field surveys are designed to allow the determination of cosmological parameters and the gravitational force law with unprecedented precision. More than ever, progress in the form of robust and accurate results will thus depend on our ability to identify and correct for flaws in the observational data and the analysis thereof. Weak lensing plays a critical role in these surveys, and is notoriously picky about data quality. I will present a few such flaws we discovered in the CCDs used for the Dark Energy Survey (DES), and how we treat them. I will also introduce two new tools that have been developed and are currently employed in DES to rapidly identify unknown flaws and to investigate the response and accuracy of the data analysis pipelines under actual survey conditions. I will demonstrate how these tools help us conduct the first weak-lensing analyses of DES. Based on findings of these first projects, I will present a novel method to identify clusters, filaments, walls, and voids with photometric redshifts, and discuss how to infer additional cosmological information from these different environments.

JPL Contact: Chaz Shapiro (4-7894)

SVCP Astrophysics

Privacy / Copyrights
  NASA Home Page
Site Manager:

CL 08-3220