The Milky Way Stellar Halo Is Twisted and Doubly Broken: Insights from DESI DR2 Milky Way Survey Observation

The Astrophysical Journal 2026 Open access

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Authors: Songting Li, Wenting Wang, Sergey E. Koposov, João A. S. Amarante, Alis J. Deason, Nathan R. Sandford, Ting S. Li, Gustavo E. Medina, Jiaxin Han, Monica Valluri, Oleg Y. Gnedin, Namitha Kizhuprakkat
+36 more Andrew P. Cooper, Leandro Beraldo e Silva, Carlos Frenk, Raymond G. Carlberg, Mika Lambert, Tian Qiu, Jessica Nicole Aguilar, Steven Ahlen, Davide Bianchi, David Brooks, Todd Claybaugh, Axel de la Macorra, Peter Doel, Jaime E. Forero-Romero, Enrique Gaztañaga, Satya Gontcho A Gontcho, Gaston Gutierrez, Dick Joyce, Robert Kehoe, Anthony Kremin, C. Lamman, Martin Landriau, Laurent Le Guillou, Ramon Miquel, Will Percival, Francisco Prada, Ignasi Pérez-Ràfols, Graziano Rossi, Eusebio Sanchez, David J. Schlegel, Ray Sharples, Joseph Harry Silber, David Sprayberry, Gregory Tarlé, Benjamin Alan Weaver, Hu Zou Hu Zou
DOI: 10.3847/1538-4357/ae41b9
Cited by: 6
References: 135

Abstract

Abstract Using K giants from the second data release (DR2) of the Dark Energy Spectroscopic Instrument (DESI) Milky Way Survey, we measure the shape, orientation, radial profile, and density anisotropies of the Milky Way (MW) stellar halo over 8 kpc < r GC < 200 kpc. We identify a triaxial stellar halo (axis ratio 10:8:7), 43° tilted from the disk, showing two break radii at ∼16 and ∼76 kpc, likely associated with Gaia-Sausage/Enceladus and the Large Magellanic Cloud (LMC), respectively. The inner stellar halo (

Fields of Study & Subjects

Stellar planetary and galactic studies Astronomy and Astrophysical Research Astrophysics and Star Formation Studies

Publication details

Journal / source
The Astrophysical Journal
Publisher
American Astronomical Society
Volume
999
Issue
1
Pages
108–108
Publication date
26 February 2026
Language
EN