An Update on LSST Sensors, and What We've Learned about Precision Measurements Using Deeply Depleted CCDs

Monday, 19 May 2014 2:30 p.m. — 3 p.m. MST

AURA Lecture Hall

NOIRLab South Colloquia
CHRISTOPHER STUBBS (Harvard University and NOAO South Visiting Astronomer)

The LSST project is making steady progress towards acquiring the sensors needed to fill the 3 Gpixel focal plane, as well as the guiding and wavefront sensors. I will describe the status of the LSST sensor development effort, which just last week received a strong committee endorsement to move forward with the initial production phase of sensor acquisition.  I'll also describe some of the features we've seen in the LSST prototype sensors, that have heavily influenced our approach to flat-fielding and instrumental signature removal. Specifically, lateral electric fields within the silicon produce anomalies in photometry, astrometry and shapes of astronomical objects. These effects have now also been clearly seen in survey data from both DES and PanSTARRS. A particularly insidious effect is intensity-dependent PSF shape.  Understanding and overcoming these effects will be essential in order to reap the full scientific benefits of the LSST survey.