Identifying High Metallicity M Giants at Intragroup Distances with SDSS

TL;DR

This paper identifies candidate high-metallicity M giant stars at intragroup distances using SDSS data, providing insights into stars ejected from the Milky Way through gravitational interactions.

Contribution

It introduces a method to select intragroup M giant candidates based on color cuts, expanding the catalog of distant stars beyond previous detections.

Findings

Identified 677 intragroup star candidates between 300 kpc and 2 Mpc.

Selected candidates include the reddest M7-M10 giants and distant L dwarfs.

Demonstrated the effectiveness of color cuts in isolating high-metallicity intragroup stars.

Abstract

Tidal stripping and three-body interactions with the central supermassive black hole may eject stars from the Milky Way. These stars would comprise a set of `intragroup' stars that trace the past history of interactions in our galactic neighborhood. Using the Sloan Digital Sky Survey DR7, we identify candidate solar metallicity red giant intragroup stars using color cuts that are designed to exclude nearby M and L dwarfs. We present 677 intragroup candidates that are selected between 300 kpc and 2 Mpc, and are either the reddest intragroup candidates (M7-M10) or are L dwarfs at larger distances than previously detected.