The QUEST RR Lyrae Survey

Yale University, New Haven CT

Investigators

Abstract

It has long been recognized that the stars and star clusters of the halo of our Galaxy are the oldest populations in the Milky Way, and therefore hold important clues to its earliest period of evolution. Despite decades of work on the halo population, little is known about its structure and its kinematics at large distances from the galactic center. It is not known, for example, if the distant halo is spherical or flattened, or if instead of a smooth density distribution, it is crisscrossed with stellar streams of debris from tidally destroyed satellite galaxies. These questions and related ones will be investigated by Dr. Robert Zinn, of Yale University, using the data collected by the QUEST survey for RR Lyrae variable stars. The QUEST camera is a 4x4 array of 2048x2048 CCDs mounted at the prime focus of the 1.0 meter clear aperture Schmidt telescope at the Llano del Hato Observatory in Venezuela. Science-grade data have been taken continuously since November 1998, including some data for the RR Lyrae survey that will be concluded with this award. The preliminary data have demonstrated the feasibility of the complete survey, which is intended to cover a total of 700 square degrees of the sky. ***