2024/12/17 by Weixiang Sun, Han Shen, Sun, Weixiang +5
Earth and Planetary Sciences · Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #High-pressure geophysics and materials #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.2412.12876
openalex publication_date 2024/12/17 · openalex created_date 2024/12/19 · openalex updated_date 2026/07/28
Galactic disk warp has been widely characterized by stellar distributions and stellar kinematics but has not been traced by stellar chemistry. Here, we use a sample with over 170,000 red clump (RC) stars selected from LAMOST and APOGEE first to establish a correlation between the north-south asymmetry in metallicity ([Fe/H]) and the disk warp. Our results indicate that the height of the [Fe/H] mid-plane for the whole RC sample stars is accurately described as Zw = 0.017 (R - 7.112)2 sin(ϕ - 9.218). This morphology aligns closely with the warp traced by Cepheids, suggesting that the disk north-south asymmetry in [Fe/H] may serve as a new tracer for the Galactic warp. Our detailed analysis of the young/thin disk stars of this RC sample suggests that its warp is well-modeled as Zw = 0.016 (R - 6.507)2 sin(ϕ - 4.240), indicating that the line of node (LON) of the Galactic warp is oriented at 4.240-1.747+1.641 degree.