PreCam, a Precursor Observational Campaign for Calibration of the Dark Energy Survey

TL;DR

PreCam is a precursor survey that creates a detailed star catalog to calibrate the Dark Energy Survey, also testing the hardware of the upcoming Dark Energy Camera.

Contribution

It provides a new, extensive standard star catalog and demonstrates the PreCam instrument's design, testing, and initial performance for DES calibration.

Findings

Catalog of nearly 100,000 standard stars created

PreCam instrument successfully tested and characterized

Preliminary data shows promising astrometric and photometric accuracy

Abstract

PreCam, a precursor observational campaign supporting the Dark Energy Survey (DES), is designed to produce a photometric and astrometric catalog of nearly a hundred thousand standard stars within the DES footprint, while the PreCam instrument also serves as a prototype testbed for the Dark Energy Camera (DECam)'s hardware and software. This catalog represents a potential 100-fold increase in Southern Hemisphere photometric standard stars, and therefore will be an important component in the calibration of the Dark Energy Survey. We provide details on the PreCam instrument's design, construction and testing, as well as results from a subset of the 51 nights of PreCam survey observations on the University of Michigan Department of Astronomy's Curtis-Schmidt telescope at Cerro Tololo Inter-American Observatory. We briefly describe the preliminary data processing pipeline that has been developed for PreCam data and the preliminary results of the instrument performance, as well as astrometry and photometry of a sample of stars previously included in other southern sky surveys.