Crowded Field Photometry with Rubin: Exploring 47 Tucanae with Data Preview 1

TL;DR

This paper evaluates Rubin Observatory's early data processing capabilities in the crowded 47 Tucanae cluster, demonstrating the potential and limitations of current pipelines and forced photometry for dense stellar environments.

Contribution

It provides an assessment of Rubin's early pipelines in crowded fields and introduces forced photometry as a method to recover sources near the cluster core.

Findings

Standard pipelines fail within 28 pc of the cluster center.

Forced photometry recovers sources down to 14 pc from the center.

Identified 14,744 potential cluster members.

Abstract

We analyze imaging from Data Preview 1 of the Vera C. Rubin Observatory to explore the performance of early LSST pipelines in the 47 Tucanae field. The coadd-\texttt{object} catalog demonstrates the depth and precision possible with Rubin, recovering well-defined color magnitude diagrams for 47 Tuc Small Magellanic Cloud. Unfortunately, the existing pipelines fail to recover sources within $\sim$28 pc of the cluster center, due to the extreme source density. Using Rubin's forced photometry on stars identified via Difference Imaging, we can recover sources down to $\sim$14 pc from the cluster center, and find 14744 potential cluster members with this extended dataset. While this forced photometry has significant systematics, our analysis showcases the potential for detailed structural studies of crowded fields with the Rubin Observatory.