White Dwarfs for Calibrating the Dark Energy Survey
Abstract
The Dark Energy Survey (DES) is surveying some 5000 square degrees in the southern hemisphere in the grizY filter system using the new Dark Energy Camera. In order to verify meeting photometric calibration requirements, we are obtaining imaging of several hundred white dwarfs (confirmed and candidates) to select nearly 100 or more hydrogen atmosphere (DA) white dwarfs for spectroscopy in the DES footprint. The spectra that are obtained will be extracted and used to derive synthetic spectra that can be compared with DES measurements from imaging in each of the DES grizY filters. This comparison should be able to verify and help calibrate the survey to a level better than 2% photometrically and to better than 0.5% in colors. We will discuss the observational and modeling effort required to develop a well-characterized DAs sample and present some preliminary results. This set would form the basis of a larger set of southern hemisphere survey calibration stars, and additionally serve as a legacy calibration set in the upcoming era of the LSST survey and the giant segmented mirror observatories. These stars will be used to establish and monitor the color zero points for the DES photometric system and can be used to search for systematic errors in the color zero points over the DES footprint. These stars will also be used as some of the primary standards for the DES photometric system which will allow nightly atmospheric monitoring during DES operations.
- Publication:
-
American Astronomical Society Meeting Abstracts #227
- Pub Date:
- January 2016
- Bibcode:
- 2016AAS...22734904A