The DECam Field of Streams: a deep view of the Milky Way halo

TL;DR

This paper presents a detailed visual map of the Milky Way halo using deep wide-area photometric surveys, revealing various stellar structures and demonstrating progress in understanding our galaxy's building blocks.

Contribution

It introduces a new visualization of the Milky Way halo structures using DECam data and an isochrone-based matched filter to identify old, metal-poor stars across large sky areas.

Findings

Identification of diverse stellar streams, dwarf galaxies, and globular clusters.

Demonstrates the effectiveness of deep, wide-area surveys in mapping galactic structures.

Highlights future improvements with LSST data.

Abstract

We present a Field of Streams visualizing stellar structures in the Milky Way halo as viewed by the Dark Energy Camera (DECam). We use $g$- and $r$-band imaging from the Dark Energy Survey and the DECam Legacy Survey, covering $18{,}700 \deg^2$ across the sky. Using an isochrone-based matched filter in $g$ vs. $g-r$, we select old and metal-poor stars in three distance bins, and generate a false-color RGB image of the number density of selected stars. The DECam Field of Streams shows a variety of Milky Way halo structures, including dwarf galaxies, globular clusters, and an abundance of stellar streams, illustrating the significant progress that has been made in recent years in uncovering the building blocks of the Milky Way's stellar halo in deep, wide-area photometric surveys. This view of our Galaxy will be improved in the coming years as the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) begins to collect data to greater depths and across a larger fraction of the sky than ever before.