The Galactic Disk North–South Asymmetry in Metallicity May Be a New Tracer for the Disk Warp
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 asymmet...
Saved in:
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2025-01-01
|
| Series: | The Astrophysical Journal Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/2041-8213/ada02a |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | 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] midplane for the whole RC sample stars is accurately described as Z _w = 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 Z _w = 0.016 ( R − 6.507) ^2 sin( ϕ − 4.240), indicating that the line of node of the Galactic warp is oriented at 4.240 ${}_{-1.747}^{+1.641}$ degrees. |
|---|---|
| ISSN: | 2041-8205 |