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...
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IOP Publishing
2025-01-01
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| Series: | The Astrophysical Journal Letters |
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| Online Access: | https://doi.org/10.3847/2041-8213/ada02a |
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| author | Weixiang Sun Han Shen Biwei Jiang Xiaowei Liu |
| author_facet | Weixiang Sun Han Shen Biwei Jiang Xiaowei Liu |
| author_sort | Weixiang Sun |
| collection | DOAJ |
| description | 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. |
| format | Article |
| id | doaj-art-7b32ebecf46d4cfba6a20b918e831713 |
| institution | OA Journals |
| issn | 2041-8205 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
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| series | The Astrophysical Journal Letters |
| spelling | doaj-art-7b32ebecf46d4cfba6a20b918e8317132025-08-20T02:08:47ZengIOP PublishingThe Astrophysical Journal Letters2041-82052025-01-019782L2410.3847/2041-8213/ada02aThe Galactic Disk North–South Asymmetry in Metallicity May Be a New Tracer for the Disk WarpWeixiang Sun0https://orcid.org/0009-0005-9277-6758Han Shen1https://orcid.org/0000-0001-8962-4132Biwei Jiang2https://orcid.org/0000-0003-3168-2617Xiaowei Liu3https://orcid.org/0000-0003-1295-2909School of Physics and Astronomy, Beijing Normal University , Beijing 100875, People’s Republic of China ; sunweixiang@bnu.edu.cn, bjiang@bnu.edu.cnSchool of Physics, University of New South Wales , Kensington, NSW 2032, Australia; ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), AustraliaSchool of Physics and Astronomy, Beijing Normal University , Beijing 100875, People’s Republic of China ; sunweixiang@bnu.edu.cn, bjiang@bnu.edu.cnSouth-Western Institute for Astronomy Research, Yunnan University , Kunming 650500, People’s Republic of China ; x.liu@ynu.edu.cnGalactic 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.https://doi.org/10.3847/2041-8213/ada02aGalaxy structureMilky Way diskStellar abundancesStellar kinematics |
| spellingShingle | Weixiang Sun Han Shen Biwei Jiang Xiaowei Liu The Galactic Disk North–South Asymmetry in Metallicity May Be a New Tracer for the Disk Warp The Astrophysical Journal Letters Galaxy structure Milky Way disk Stellar abundances Stellar kinematics |
| title | The Galactic Disk North–South Asymmetry in Metallicity May Be a New Tracer for the Disk Warp |
| title_full | The Galactic Disk North–South Asymmetry in Metallicity May Be a New Tracer for the Disk Warp |
| title_fullStr | The Galactic Disk North–South Asymmetry in Metallicity May Be a New Tracer for the Disk Warp |
| title_full_unstemmed | The Galactic Disk North–South Asymmetry in Metallicity May Be a New Tracer for the Disk Warp |
| title_short | The Galactic Disk North–South Asymmetry in Metallicity May Be a New Tracer for the Disk Warp |
| title_sort | galactic disk north south asymmetry in metallicity may be a new tracer for the disk warp |
| topic | Galaxy structure Milky Way disk Stellar abundances Stellar kinematics |
| url | https://doi.org/10.3847/2041-8213/ada02a |
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