The Gaia-LSST Synergy: resolved stellar populations in selected Local Group stellar systems

TL;DR

This study leverages LSST and Gaia data to comprehensively analyze resolved stellar populations in six Local Group systems, aiming to map their structures, histories, and tidal features with unprecedented detail.

Contribution

It introduces a novel approach combining Gaia and LSST data to study stellar populations, distances, and structures of Local Group systems in a unified framework.

Findings

Mapping of stellar populations and structures up to halo peripheries.

Enhanced distance measurements using variable stars and RGB tip.

Detection of tidal streams and detailed star formation histories.

Abstract

This project aims at exploiting the wide-field and limiting-magnitude capabilities of the LSST to fully characterise the resolved stellar populations in/around six Local Group stellar systems of different morphological type at ~30 to ~400 kpc distance from us. We selected targets that host red giant branch (RGB) stars which are within the reach of Gaia and not yet (all) saturated with the LSST. We will use RR Lyrae stars, Cepheids, SX Phoenicis, delta Scuti stars and Long Period Variables, along with the Color Magnitude Diagram of the resolved stellar populations in these 6 systems to: i) trace their different stellar generations over a spatial extension and with a depth that only the LSST can achieve; ii) measure their distances using variable stars of different type/parent stellar population and the Tip of the RGB; iii) map their 3D structures up to the periphery of their halos; iv) search for tidal streams; and v) study their Star Formation Histories over unprecedented large fractions of their bodies. Our ultimate goals are to provide a complete picture of these nearby stellar systems all the way through to their periphery, and to directly link and cross-calibrate the Gaia and LSST projects.