Pan-STARRS1: Galaxy Clustering in the Small Area Survey 2
Abstract
The Pan-STARRS1 survey is currently obtaining imaging in 5 bands (grizy) for the 3π steradian survey, one of the largest optical surveys ever conducted. The finished survey will have spatially varying depth, due to the survey strategy. This paper presents a method to correct galaxy number counts and galaxy clustering for this potential systematic based on a simplified signal to noise measurement. A star and galaxy separation method calibrated using realistic synthetic images is also presented, along with an approach to mask bright stars. By using our techniques on a ~69 sq. degree region of science verification data this paper shows PS1 measurements of the two point angular correlation function as a function of apparent magnitude agree with measurements from deeper, smaller surveys. Clustering measurements appear reliable down to a magnitude limit of rps<22.5. Additionally, stellar contamination and false detection issues are discussed and quantified. This work is the second of two papers which pave the way for the exploitation of the full 3π survey for studies of large scale structure.