The Circular Velocity Curve of the Milky Way from 5–25 kpc Using Luminous Red Giant Branch Stars
We present a sample of 254,882 luminous red giant branch (LRGB) stars selected from the APOGEE and LAMOST surveys. By combining photometric and astrometric information from the Two Micron All Sky Survey and Gaia survey, the precise distances of the sample stars are determined by a supervised machine...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/acadd9 |
| _version_ | 1797697204006158336 |
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| author | Yuan Zhou Xinyi Li Yang Huang Huawei Zhang |
| author_facet | Yuan Zhou Xinyi Li Yang Huang Huawei Zhang |
| author_sort | Yuan Zhou |
| collection | DOAJ |
| description | We present a sample of 254,882 luminous red giant branch (LRGB) stars selected from the APOGEE and LAMOST surveys. By combining photometric and astrometric information from the Two Micron All Sky Survey and Gaia survey, the precise distances of the sample stars are determined by a supervised machine-learning algorithm: the gradient-boosted decision trees. To test the accuracy of the derived distances, member stars of globular clusters (GCs) and open clusters are used. The tests by cluster member stars show a precision of about 10% with negligible zero-point offsets, for the derived distances of our sample stars. The final sample covers a large volume of the Galactic disk(s) and halo of 0 < R < 30 kpc and ∣ Z ∣ ≤ 15 kpc. The rotation curve (RC) of the Milky Way across the radius of 5 ≲ R ≲ 25 kpc has been accurately measured with ∼54,000 stars of the thin disk population selected from the LRGB sample. The derived RC shows a weak decline along R with a gradient of −1.83 ± 0.02 (stat.) ± 0.07 (sys.) km s ^−1 kpc ^−1 , in excellent agreement with the results measured by previous studies. The circular velocity at the solar position, yielded by our RC is 234.04 ± 0.08 (stat.) ± 1.36 (sys.) km s ^−1 , again in great consistency with other independent determinations. From the newly constructed RC, as well as constraints from other data, we have constructed a mass model for our Galaxy, yielding a mass of the dark matter halo of M _200 = (8.05 ± 1.15) × 10 ^11 M _⊙ with a corresponding radius of R _200 = 192.37 ± 9.24 kpc and a local dark matter density of 0.39 ± 0.03 GeV cm ^−3 . |
| first_indexed | 2024-03-12T03:36:56Z |
| format | Article |
| id | doaj.art-9b606cb9cc0445fe901b924823b513bd |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-12T03:36:56Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-9b606cb9cc0445fe901b924823b513bd2023-09-03T13:08:36ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-0194627310.3847/1538-4357/acadd9The Circular Velocity Curve of the Milky Way from 5–25 kpc Using Luminous Red Giant Branch StarsYuan Zhou0Xinyi Li1https://orcid.org/0000-0003-2086-0684Yang Huang2https://orcid.org/0000-0003-3250-2876Huawei Zhang3https://orcid.org/0000-0002-7727-1699South-Western Institute for Astronomy Research, Yunnan University , Kunming 650500, People's Republic of China ; bashiyi@163.com, li_xinyi621@mail.ynu.edu.cnSouth-Western Institute for Astronomy Research, Yunnan University , Kunming 650500, People's Republic of China ; bashiyi@163.com, li_xinyi621@mail.ynu.edu.cnUniversity of Chinese Academy of Sciences , Beijing 100049, People's Republic of China ; huangyang@bao.ac.cn; National Astronomical Observatories, Chinese Academy of Sciences , Beijing 100012, People's Republic of ChinaDepartment of Astronomy, Peking University , Beijing 100871, People's Republic of China; Kavli Institute for Astronomy and Astrophysics, Peking University , Beijing 100871, People's Republic of ChinaWe present a sample of 254,882 luminous red giant branch (LRGB) stars selected from the APOGEE and LAMOST surveys. By combining photometric and astrometric information from the Two Micron All Sky Survey and Gaia survey, the precise distances of the sample stars are determined by a supervised machine-learning algorithm: the gradient-boosted decision trees. To test the accuracy of the derived distances, member stars of globular clusters (GCs) and open clusters are used. The tests by cluster member stars show a precision of about 10% with negligible zero-point offsets, for the derived distances of our sample stars. The final sample covers a large volume of the Galactic disk(s) and halo of 0 < R < 30 kpc and ∣ Z ∣ ≤ 15 kpc. The rotation curve (RC) of the Milky Way across the radius of 5 ≲ R ≲ 25 kpc has been accurately measured with ∼54,000 stars of the thin disk population selected from the LRGB sample. The derived RC shows a weak decline along R with a gradient of −1.83 ± 0.02 (stat.) ± 0.07 (sys.) km s ^−1 kpc ^−1 , in excellent agreement with the results measured by previous studies. The circular velocity at the solar position, yielded by our RC is 234.04 ± 0.08 (stat.) ± 1.36 (sys.) km s ^−1 , again in great consistency with other independent determinations. From the newly constructed RC, as well as constraints from other data, we have constructed a mass model for our Galaxy, yielding a mass of the dark matter halo of M _200 = (8.05 ± 1.15) × 10 ^11 M _⊙ with a corresponding radius of R _200 = 192.37 ± 9.24 kpc and a local dark matter density of 0.39 ± 0.03 GeV cm ^−3 .https://doi.org/10.3847/1538-4357/acadd9Galaxy rotation curvesDistance measureMilky Way dynamicsGalaxy kinematics |
| spellingShingle | Yuan Zhou Xinyi Li Yang Huang Huawei Zhang The Circular Velocity Curve of the Milky Way from 5–25 kpc Using Luminous Red Giant Branch Stars The Astrophysical Journal Galaxy rotation curves Distance measure Milky Way dynamics Galaxy kinematics |
| title | The Circular Velocity Curve of the Milky Way from 5–25 kpc Using Luminous Red Giant Branch Stars |
| title_full | The Circular Velocity Curve of the Milky Way from 5–25 kpc Using Luminous Red Giant Branch Stars |
| title_fullStr | The Circular Velocity Curve of the Milky Way from 5–25 kpc Using Luminous Red Giant Branch Stars |
| title_full_unstemmed | The Circular Velocity Curve of the Milky Way from 5–25 kpc Using Luminous Red Giant Branch Stars |
| title_short | The Circular Velocity Curve of the Milky Way from 5–25 kpc Using Luminous Red Giant Branch Stars |
| title_sort | circular velocity curve of the milky way from 5 25 kpc using luminous red giant branch stars |
| topic | Galaxy rotation curves Distance measure Milky Way dynamics Galaxy kinematics |
| url | https://doi.org/10.3847/1538-4357/acadd9 |
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