A ∧-like metallicity profile in the disk of the Sagittarius dwarf galaxy

@misc{guo2026like,
  title = {{A $\wedge$-like metallicity profile in the disk of the Sagittarius dwarf galaxy}},
  author = {Zixi Guo and Xiang-Xiang Xue and Jiang Chang and Chao Liu and Zehao Zhong and Bingqing Zhang and Ruizhi Zhang and Shi Shao and Gang Zhao and Zhuohan Li and Xi Kang and Jie Wang and Jianhui Lian and Haining Li and Ruizheng Jiang},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2610.27526},
  eprint = {2610.27526},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2610.27526},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - A ∧-like metallicity profile in the disk of the Sagittarius dwarf galaxy
AU  - Zixi Guo
AU  - Xiang-Xiang Xue
AU  - Jiang Chang
AU  - Chao Liu
AU  - Zehao Zhong
AU  - Bingqing Zhang
AU  - Ruizhi Zhang
AU  - Shi Shao
AU  - Gang Zhao
AU  - Zhuohan Li
AU  - Xi Kang
AU  - Jie Wang
AU  - Jianhui Lian
AU  - Haining Li
AU  - Ruizheng Jiang
PY  - 2026
DA  - 2026/10/20
PB  - arXiv
DO  - 10.48550/arxiv.2610.27526
UR  - https://arxiv.org/abs/2610.27526
AB  - Unveiling the properties of the progenitors that formed the tidal structures of the Milky Way (MW) is essential for exploring the MW's assembly history. Such studies further afford a unique opportunity to dissect the formation and evolution of dwarf galaxies by contrasting surviving and disrupted systems. However, reconstructing the intrinsic structure of progenitors solely from the positions and velocities of their tidal debris remains a formidable challenge. Here, we decode the chemo-kinematic signatures embedded in the stellar streams of the Sagittarius (Sgr) dwarf galaxy through N-body simulations. Our simulation reproduces a vertical metallicity gradient in the Sgr streams. We show that this feature is naturally explained if the stream originated from a disk component with a ∧-like metallicity profile. Remarkably, similar metallicity profiles are identified in MaNGA survey data for a few (3/217) field dwarf galaxies, suggesting this feature is rare but not unique to Sgr. The vertical metallicity gradient of stellar streams preserves extra detailed galactic fossil records, enabling quantitative reconstruction of the peculiar structure of the satellite galaxy. The similar metallicity profiles of Sgr and MW raise the question of a possible special coevolution.
ER  -