Abstract
The Milky Way’s neutral hydrogen (H i) disk is warped and flared 1,2 . However, a dearth of accurate H i-based distances has thus far prevented the development of an accurate Galactic Disk model. Moreover, the extent to which our Galaxy’s stellar and gas disk morphologies are mutually consistent is also unclear. Classical Cepheids, primary distance indicators with distance accuracies of 3–5% (ref. 3 ), offer a unique opportunity to develop an intuitive and accurate three-dimensional picture. Here, we establish a robust Galactic Disk model based on 1,339 classical Cepheids. We provide strong evidence that the warp’s line of nodes is not oriented in the Galactic Centre–Sun direction. Instead, it subtends a mean angle of 17.5° ± 1° (formal) ± 3° (systematic) and exhibits a leading spiral pattern. Our Galaxy thus follows Briggs’ rule for spiral galaxies 4 , which suggests that the origin of the warp is associated with torques forced by the massive inner disk 5 . The stellar disk traced by Cepheids follows the gas disk in terms of their amplitudes; the stellar disk extends to at least 20 kpc (refs. 6,7 ). This morphology provides a crucial, updated map for studies of the kinematics and archaeology of the Galactic Disk.
| Language | English |
|---|---|
| Pages | 320-325 |
| Number of pages | 6 |
| Journal | Nature Astronomy |
| Volume | 3 |
| Issue number | 4 |
| Early online date | Feb 2019 |
| DOIs | |
| Publication status | Published - Apr 2019 |
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An intuitive 3D map of the Galactic warp’s precession traced by classical Cepheids. / Chen, Xiaodian; Wang, Shu; Deng, Licai; de Grijs, Richard; Liu, Chao; Tian, Hao.
In: Nature Astronomy, Vol. 3, No. 4, 04.2019, p. 320-325.Research output: Contribution to journal › Article › Research › peer-review
TY - JOUR
T1 - An intuitive 3D map of the Galactic warp’s precession traced by classical Cepheids
AU - Chen,Xiaodian
AU - Wang,Shu
AU - Deng,Licai
AU - de Grijs,Richard
AU - Liu,Chao
AU - Tian,Hao
PY - 2019/4
Y1 - 2019/4
N2 - The Milky Way’s neutral hydrogen (H i) disk is warped and flared 1,2 . However, a dearth of accurate H i-based distances has thus far prevented the development of an accurate Galactic Disk model. Moreover, the extent to which our Galaxy’s stellar and gas disk morphologies are mutually consistent is also unclear. Classical Cepheids, primary distance indicators with distance accuracies of 3–5% (ref. 3 ), offer a unique opportunity to develop an intuitive and accurate three-dimensional picture. Here, we establish a robust Galactic Disk model based on 1,339 classical Cepheids. We provide strong evidence that the warp’s line of nodes is not oriented in the Galactic Centre–Sun direction. Instead, it subtends a mean angle of 17.5° ± 1° (formal) ± 3° (systematic) and exhibits a leading spiral pattern. Our Galaxy thus follows Briggs’ rule for spiral galaxies 4 , which suggests that the origin of the warp is associated with torques forced by the massive inner disk 5 . The stellar disk traced by Cepheids follows the gas disk in terms of their amplitudes; the stellar disk extends to at least 20 kpc (refs. 6,7 ). This morphology provides a crucial, updated map for studies of the kinematics and archaeology of the Galactic Disk.
AB - The Milky Way’s neutral hydrogen (H i) disk is warped and flared 1,2 . However, a dearth of accurate H i-based distances has thus far prevented the development of an accurate Galactic Disk model. Moreover, the extent to which our Galaxy’s stellar and gas disk morphologies are mutually consistent is also unclear. Classical Cepheids, primary distance indicators with distance accuracies of 3–5% (ref. 3 ), offer a unique opportunity to develop an intuitive and accurate three-dimensional picture. Here, we establish a robust Galactic Disk model based on 1,339 classical Cepheids. We provide strong evidence that the warp’s line of nodes is not oriented in the Galactic Centre–Sun direction. Instead, it subtends a mean angle of 17.5° ± 1° (formal) ± 3° (systematic) and exhibits a leading spiral pattern. Our Galaxy thus follows Briggs’ rule for spiral galaxies 4 , which suggests that the origin of the warp is associated with torques forced by the massive inner disk 5 . The stellar disk traced by Cepheids follows the gas disk in terms of their amplitudes; the stellar disk extends to at least 20 kpc (refs. 6,7 ). This morphology provides a crucial, updated map for studies of the kinematics and archaeology of the Galactic Disk.
UR - http://www.scopus.com/inward/record.url?scp=85064049708&partnerID=8YFLogxK
U2 - 10.1038/s41550-018-0686-7
DO - 10.1038/s41550-018-0686-7
M3 - Article
VL - 3
SP - 320
EP - 325
JO - Nature Astronomy
T2 - Nature Astronomy
JF - Nature Astronomy
SN - 2397-3366
IS - 4
ER -