Chemical Cartography of the Sagittarius Stream with Gaia

2023/07/17 by Emily C. Cunningham, Jason A. S. Hunt, Cunningham, Emily C. +14 · 2 voices · 1 citation
Physics and Astronomy · #Stellar, planetary, and galactic studies #Astronomy and Astrophysical Research #Gamma-ray bursts and supernovae

paper · pdf · doi:10.48550/arxiv.2307.08730

Abstract

The stellar stream connected to the Sagittarius (Sgr) dwarf galaxy is the most massive tidal stream that has been mapped in the Galaxy, and is the dominant contributor to the outer stellar halo of the Milky Way. We present metallicity maps of the Sgr stream, using 34,240 red giant branch stars with inferred metallicities from Gaia BP/RP spectra. This sample is larger than previous samples of Sgr stream members with chemical abundances by an order of magnitude. We measure metallicity gradients with respect to Sgr stream coordinates (Λ, B), and highlight the gradient in metallicity with respect to stream latitude coordinate B, which has not been observed before. We find ∇ [M/H] = -2.48 ± 0.08 × 10^-2 dex/deg above the stream track (B>B₀ where B₀=1.5 deg is the latitude of the Sgr remnant) and ∇ [M/H] =- 2.02 ± 0.08 × 10^-2 dex/deg below the stream track (B

Cited by

• Mapping the Distant and Metal-Poor Milky Way with SDSS-V

Discussions

• The chemical composition of the Sagittarius stream becomes clearer thanks to Cunningham et al., who use metallicity from the Gaia XP spectra to map how it varies across the sky (arxiv.org/abs/2307.087 [bsky, 14 points, 1 comments]
• 🔭 On arxiv this evening: SAO REU alum Emily Cunningham has a paper mapping out metallicity gradients in the Sgr Stream https://arxiv.org/abs/2307.08730 [bsky, 7 points, 0 comments]

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