An intuitive 3D map of the Galactic warp's precession traced by classical Cepheids

Abstract

The Milky Way's neutral hydrogen (HI) disk is warped and flared. However, a dearth of accurate HI-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%, offer a unique opportunity to develop an intuitive and accurate three-dimensional picture. Here, we establish a robust Galactic disk model based on 1339 classical Cepheids. We provide strong evidence that the warp's line of nodes is not oriented in the Galactic Center-Sun direction. Instead, it subtends a mean angle of 17.5 \pm 1 (formal) \pm 3 (systematic) and exhibits a leading spiral pattern. Our Galaxy thus follows Briggs' rule for spiral galaxies, which suggests that the origin of the warp is associated with torques forced by the massive inner disk. The stellar disk traced by Cepheids follows the gas disk in terms of their amplitudes; the stellar disk extends to at least 20 kpc. This morphology provides a crucial, updated map for studies of the kinematics and archaeology of the Galactic disk.

23 pages, 9 figures, Published in Nature Astronomy

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Cited by in corpus (64)

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• The SEDIGISM survey: first data release and overview of the Galactic structure
• The SEDIGISM survey: Molecular clouds in the inner Galaxy
• The Rotation Curve, Mass Distribution and Dark Matter Content of the Milky Way from Classical Cepheids
• Mapping the Galactic Metallicity Gradient with Open Clusters: The State-of-the-Art and Future Challenges
• Classical Cepheid period-Wesenheit-metallicity relation in the Gaia bands
• The OGLE Collection of Variable Stars. Nearly 66,000 Mira stars in the Milky Way
• Mapping the Galactic disk with the LAMOST and Gaia Red clump sample. VI: An evidence for the long lived non-steady warp of non-gravitational scenarios
• A Tilted Dark Halo Origin of the Galactic Disk Warp and Flare
• Tracing the Milky Way warp and spiral arms with classical Cepheids
• The volumetric star formation law in the Milky Way
• The Pristine survey XIII: Uncovering the very metal-poor tail of the thin disc
• Oxygen, sulfur, and iron radial abundance gradients of classical Cepheids across the Galactic thin disk
• Structure of the outer Galactic disc with Gaia-DR2
• A three-dimensional map of the Milky Way using 66,000 Mira variable stars
• Weighing the Galactic disk using phase-space spirals III. Probing distant regions of the disk using the Gaia EDR3 proper motion sample
• A twisted and precessing Cepheid warp in the outer Milky Way disc
• Variable star classification across the Galactic bulge and disc with the VISTA Variables in the Vía Láctea survey
• The SEDIGISM survey: The influence of spiral arms on the molecular gas distribution of the inner Milky Way
• The far side of the Galactic bar/bulge revealed through semi-regular variables
• The structure of the Milky Way based on unWISE 3.4$\mu$m integrated photometry
• The Great Wave: Evidence of a large-scale vertical corrugation propagating outwards in the Galactic disc
• Warp and flare of the old Galactic disc as traced by the red clump stars
• The Milky Way as Seen by Classical Cepheids II: Spiral Structure
• Age-metallicity dependent stellar kinematics of the Milky Way disc from LAMOST and Gaia
• Bending waves excited by irregular gas inflow along warps
• Mapping the Galactic disk with the LAMOST and Gaia red clump sample: IV: the kinematic signature of the Galactic warp
• A slightly oblate dark matter halo revealed by a retrograde precessing Galactic disk warp
• The Milky Way, Coming into Focus: Precision Astrometry Probes its Evolution, and its Dark Matter
• The tangled warp of the Milky Way
• Identification of Absorption Lines of Heavy Metals in the Wavelength Range 0.97--1.32 Micron
• Shape of the outer stellar warp in the Large Magellanic Cloud disk
• Evidence for Populations-dependent vertical motions and the Long-lived Non-Steady Lopsided Milky Way Warp
• Vertical Structure and Kinematics of the Galactic Outer Disk
• Warped Disk Galaxies. I. Linking U type Warps in Groups/Clusters to Jellyfish Galaxies
• Line-depth ratios as indicators of effective temperature and surface gravity
• Exploring the structure and kinematics of the Milky Way through A stars
• 3D Parameter Maps of Red Clump Stars in the Milky Way -- Absolute Magnitudes and Intrinsic Colors
• Internally-driven warps in disc galaxies
• The Outer spiral arm of the Milky Way using Red Clump stars
• The completeness of the open cluster census towards the Galactic anticentre
• Search for Classical Cepheids in Galactic Open Clusters and Calibration of the Period Wesenheit Metallicity Relation in the Gaia Bands
• Measuring the Streaming motion in the Milky Way disc with Gaia EDR3 +
• Spiral arms and the angular momentum gap in Milky Way Cepheids
• GaiaUnlimited: The old stellar disc of the Milky Way as traced by the Red Clump
• Kinematical signatures: Distinguishing between warps and radial flows
• Calibrating the Cepheid Period--Wesenheit Relation in the Gaia Bands using Galactic Open Cluster Cepheids
• Towards a fully consistent Milky Way disk model V. The disk model for 4 $-$ 14 kpc
• How stars formed in warps settle into (and contaminate) thick discs
• RR Lyrae stars trace the Milky Way warp
• Two-point correlation function studies for the Milky Way: discovery of spatial clustering from disk excitations and substructure
• Detailed Mapping of the Galactic Disk Structure in the Solar Neighborhood through LAMOST K Dwarfs
• A path towards constraining the evolution of the interstellar medium and outflows in the Milky Way using APOGEE
• A Wave-Corrected Assessment of the Local Midplane
• Ancient Luoyang Bridge reveals a simple metagrating model in optics
• Star formation in the circumgalactic high-velocity cloud Complex H
• Azimuthal Misalignments in Stellar Warp Structure as Dynamical Tracers of Mergers in Milky Way-like Galaxies
• Mapping the Milky Way with Gaia Bp/Rp spectra-IV: the broken and asymmetric density profile of the stellar disk traced by a large sample of red clumps
• Dependence of pulsation mode of Cepheids on metallicity
• Identifying Periodic Variable Stars and Eclipsing Binary Systems with Long-Term Las Cumbres Observatory Photometric Monitoring of ZTF J0139+5245
• No memory of past warps in the vertical density structure of galaxies
• Cepheid Metallicity in the Leavitt Law (C--MetaLL) survey: VIII. High-Resolution IGRINS Spectroscopy of 23 Classical Cepheids: Validating NIR Abundances