The spiral structure of the Milky Way

Abstract

The morphology and kinematics of the spiral structure of the Milky Way is a long-standing problem in astrophysics. In this review we firstly summarize various methods with different tracers used to solve this puzzle. The astrometry of Galactic sources is gradually alleviating this difficult situation caused mainly by large distance uncertainties, as we can currently obtain accurate parallaxes (a few $\mu$as) and proper motions ($\approx$ 1 km~s${}^{-1}$) by using Very Long Baseline Interferometry (VLBI). On the other hand, Gaia mission is providing the largest, uniform sample of parallaxes for O-type stars in the entire Milky Way. Based upon the VLBI maser and Gaia O-star parallax measurements, nearby spiral structures: the Perseus, Local, Sagittarius and Scutum arms are determined in unprecedented detail. Meanwhile, we estimate fundamental Galactic parameters, the distance to the Galactic center, $R_0$, to be 8.35 $\pm$ 0.18 kpc, a circular rotation speed at the Sun, ${\Theta }_0$, to be 240 $\pm$ 10 km~s${}^{-1}$. We found kinematic differences between O stars and interstellar masers: the O stars, on average, rotate faster, $>$~8~ km s${}^{-1}$ than maser-traced high-mass star forming regions.

arXiv comment24 pages, 8 figures. Research in Astronomy and Astrophysics, invited review

References in corpus (103)

• Gaia Data Release 2. Summary of the contents and survey properties
• The Gaia mission
• The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI: Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections
• The Milky Way in Molecular Clouds: A New Complete CO Survey
• Trigonometric Parallaxes of High Mass Star Forming Regions: the Structure and Kinematics of the Milky Way
• A New Electron Density Model for Estimation of Pulsar and FRB Distances
• Trigonometric Parallaxes of Massive Star Forming Regions: VI. Galactic Structure, Fundamental Parameters and Non-Circular Motions
• New catalogue of optically visible open clusters and candidates
• The distance to the Orion Nebula
• The Proper Motion of Sgr A*: II. The Mass of Sgr A*
• Global survey of star clusters in the Milky Way II. The catalogue of basic parameters
• Three Dimensional Structure of the Milky Way Disk
• Physical properties of molecular clouds for the entire Milky Way disk
• The Distance to the Perseus Spiral Arm in the Milky Way
• Parallaxes and proper motions of interstellar masers toward the Cygnus X star-forming complex. I. Membership of the Cygnus X region
• The Equilibrium State of Molecular Regions in the Outer Galaxy
• The observed spiral structure of the Milky Way
• Dawes Review 4: Spiral Structures in Disc Galaxies
• Kinematic Distances to Molecular Clouds identified in the Galactic Ring Survey
• Gas Dynamics and Large-Scale Morphology of the Milky Way Galaxy
• Three-Dimensional Distribution of the ISM in the Milky Way Galaxy: II. The Molecular Gas Disk
• A Trigonometric Parallax of Sgr B2
• The Spiral Structure of the Outer Milky Way in Hydrogen
• Trigonometric Parallaxes of Massive Star Forming Regions: II. Cep A & NGC 7538
• Water maser motions in W3(OH) and a determination of its distance
• ON the Nature of the Local Spiral Arm of the Milky Way
• A Uniform Catalog of Molecular Clouds in the Milky Way
• Trigonometric Parallaxes of Massive Star Forming Regions: I. S 252 & G232.6+1.0
• Micro-Arcsecond Radio Astrometry
• Trigonometric Parallax of W51 Main/South
• Fundamental Parameters of the Milky Way Galaxy Based on VLBI astrometry
• The Bar and Spiral Structure Legacy (BeSSeL) Survey: Mapping the Milky Way with VLBI Astrometry
• Gas flow models in the Milky Way embedded bars
• The RMS Survey: Galactic distribution of massive star formation
• Direct determination of the spiral pattern rotation speed of the Galaxy
• Trigonometric Parallaxes of 6.7 GHz Methanol Masers
• Parallaxes for W49N and G048.60+0.02: Distant Star Forming Regions in the Perseus Spiral Arm
• A Parallactic Distance of 389 +24/-21 parsecs to the Orion Nebula Cluster from Very Long Baseline Array Observations
• Trigonometric Parallaxes of Massive Star Forming Regions: VIII. G12.89+0.49, G15.03-0.68 (M17) and G27.36-0.16
• Trigonometric parallaxes of star forming regions in the Sagittarius spiral arm
• The spiral structure of our Milky Way Galaxy
• Astrometry of Galactic Star Forming Region Sharpless 269 with VERA : Parallax Measurements and Constraint on Outer Rotation Curve
• Three-Dimensional Distribution of the ISM in the Milky Way Galaxy: III. The Total Neutral Gas Disk
• Pulsar Rotation Measures and Large-scale Magnetic Field Reversals in the Galactic Disk
• The Parallax of W43: a Massive Star Forming Complex near the Galactic Bar
• Spatial distribution of Galactic HII regions
• Milky Way Kinematics: Measurements at the Subcentral Point of the Fourth Quadrant
• Trigonometric Parallaxes of Massive Star Forming Regions: III. G59.7+0.1 and W 51 IRS2
• Trigonometric Parallaxes of Star Forming Regions in the Perseus Spiral Arm
• A Molecular Spiral Arm in the Far Outer Galaxy
• Trigonometric Parallaxes of Massive Star Forming Regions: V. G23.01-0.41 and G23.44-0.18
• 3D Distribution of Molecular Gas in the Barred Milky Way
• The masses, and the mass discrepancy of O-type stars
• Trigonometric Parallaxes of Massive Star Forming Regions: IV. G35.20-0.74 and G35.20-1.74
• Methanol and water masers in IRAS 20126+4104: The distance, the disk, and the jet
• Trigonometric parallaxes to star-forming regions within 4 kpc of the galactic center
• Distance to VY Canis Majoris with VERA
• The local spiral structure of the Milky Way
• Finding Distant Galactic HII Regions
• The Outer Disk of the Milky Way Seen in 21-cm Absorption
• Trigonometric Parallaxes of Star Forming Regions in the Scutum Spiral Arm
• A Possible Extension of the Scutum-Centaurus Arm into the Outer Second Quadrant
• A comparison of the local spiral structure from Gaia DR2 and VLBI maser parallaxes
• Mapping Spiral Structure on the far side of the Milky Way
• The Green Bank Telescope HII Region Discovery Survey: III. Kinematic Distances
• Giant molecular clouds and massive star formation in the southern milky way
• Astrometry of H${}_2$O Masers in Nearby Star-Forming Regions with VERA. III. IRAS 22198+6336 in L1204G
• Trigonometric Parallaxes of Massive Star Forming Regions: G012.88+0.48 and W33
• The Three-Dimensional Spatial Distribution of Interstellar Gas in the Milky Way: Implications for Cosmic Rays and High-Energy Gamma-Ray Emissions
• Annual Parallax Measurements of an Infrared Dark Cloud MSXDC G034.43+00.24 with VERA
• Offset between stellar spiral arms and gas arms of the Milky Way
• Trigonometric Parallaxes of Massive Star-Forming Regions: VII. G9.62+0.20 and the Expanding 3 KPC-ARM
• The morphology of the Milky Way - I. Reconstructing CO maps from simulations in fixed potentials
• Catalog of observed tangents to the spiral arms in the Milky Way galaxy
• Parallaxes of Star Forming Regions in the Outer Spiral Arm of the Milky Way
• A Distant Extended Spiral Arm in the Fourth Quadrant of the Milky Way
• The spiral structure of the Milky Way
• Distance and Proper Motion Measurement of the Red Supergiant, S Persei, with VLBI H2O Maser Astrometry
• Molecular Gas, Kinematics, and OB Star Formation in the Spiral Arms of the Southern Milky Way
• Distance to NGC 281 in a Galactic Fragmenting Superbubble: Parallax Measurements with VERA
• The distance to a star forming region in the Outer arm of the Galaxy
• A CGPS Look at the Spiral Structure of the Outer Milky Way I: Distances and Velocities to Star Forming Regions
• On the Interpretation of the l-v Features in the Milky Way Galaxy
• Astrometry of Galactic Star-Forming Region ON2N with VERA: Estimation of the Galactic Constants
• Distance to G14.33-0.64 in the Sagittarius Spiral Arm: H2O Maser Trigonometric Parallax with VERA
• The morphology of the Milky Way - II. Reconstructing CO maps from disc galaxies with live stellar distributions
• Characteristics of Spiral Arms in Late-type Galaxies
• The nature of the methanol maser ring G23.657-00.127
• The Distance and Size of the Red Hypergiant NML Cyg from VLBA and VLA Astrometry
• Astrometry of H${}_2$O masers in the massive star--forming region IRAS 06061+2151 with VERA
• Trigonometric Parallaxes of Massive Star-Forming Regions. IX. The Outer Arm in the First Quadrant
• A Precise Distance to IRAS 00420+5530 via H2O Maser Parallax with the VLBA
• Astrometry of Galactic Star-Forming Region Onsala 1 with VERA: Estimation of Angular Velocity of Galactic Rotation at Sun
• Molecular clouds in the extreme outer Galaxy between $l=34.75^{\circ }$ to $45.25^{\circ }$
• Molecular Clouds in the North American and Pelican Nebulae: Structures
• A substructure inside spiral arms, and a mirror image across the Galactic Meridian
• An Outer Arm in the Second Galactic Quadrant: Structure
• The Molecular Structures of Local Arm and Perseus Arm in the Galactic Region of l=[139.75,149.75]${}^{\circ }$, b=[-5.25,5.25]${}^{\circ }$
• Astrometry of Star Forming Region IRAS 05137+3919 in the far outer Galaxy
• The Distant Outer Gas Arm Between l=35d and l=45d
• Streaming Motions and Kinematic Distances to Molecular Clouds
• H2O maser motions and the distance of the star forming region G192.16-3.84
• Understanding our Galaxy - key contributions from the Parkes telescope

Cited by in corpus (37)

• Galactic spiral structure revealed by Gaia EDR3
• A large catalogue of molecular clouds with accurate distances within 4 kpc of the Galactic disk
• Gas Dynamics in the Galaxy: Total Mass Distribution and the Bar Pattern Speed
• Mapping the Galactic Metallicity Gradient with Open Clusters: The State-of-the-Art and Future Challenges
• Evolution of the local spiral structure of the Milky Way revealed by open clusters
• The spiral structure of the Milky Way
• Mapping Luminous Hot Stars in the Galaxy
• The Galactic spiral structure as revealed by O- and early B-type stars
• Local spiral structure based on the Gaia EDR3 parallaxes
• A Blind All-sky Search for Star Clusters in Gaia EDR3: 886 Clusters within 1.2 kpc of the Sun
• New Open Cluster candidates Found in Galactic Disk Using Gaia DR2/EDR3 Data
• Discovery of the black hole X-ray binary transient MAXIJ1348-630
• What Does the Milky Way Look Like?
• The spiral structure in the Solar neighborhood
• Molecular cloud distances based on the MWISP CO survey and Gaia DR2
• Using classical Cepheids to study the far side of the Milky Way disk. II. The spiral structure in the first and fourth Galactic quadrants
• The SEDIGISM survey: The influence of spiral arms on the molecular gas distribution of the inner Milky Way
• Young stars as tracers of a barred-spiral Milky Way
• Stellar Overdensity in the Local Arm in Gaia DR2
• Segments of spiral arms of the Galaxy traced by classical Cepheids: Effects of age heterogeneity
• Solar System Migration Points to a Renewed Concept: Galactic Habitable Orbits
• Discovery of a new supernova remnant G21.8-3.0
• Parallax-based Distances to Galactic Hii Regions: Nearby Spiral Structure
• Spatial and velocity offsets of Galactic masers from the centers of spiral arms
• The distances to molecular clouds in the fourth Galactic quadrant
• The Outer spiral arm of the Milky Way using Red Clump stars
• HI Self-absorption toward the Cygnus X North: From Atomic Filament to Molecular Filament
• The Effect of Light Deflection by Solar System Objects on High-Precision SKA Astrometry
• Redetermination of the Parameters of the Galactic Spiral Pattern from Classical Cepheids
• New method for estimating molecular cloud distances based on Gaia, 2MASS, and the TRILEGAL galaxy model
• Estimation of the Parameters of the Spiral Pattern in the Galaxy Based on a Sample of Classical Cepheids
• Autonomous Gaussian decomposition of the Galactic Ring Survey. II. The Galactic distribution of 13CO
• Astrophysical Parameters of the Open Cluster Berkeley 6
• Spatial offsets between interstellar bone-like filaments, radio masers, and cold diffuse CO gas, in the Scutum spiral arm
• On the most reliable value of the Galactic aberration constant
• Galaxy rotation curve based on RGB stars from the Gaia DR3 catalogue
• Influence of interstellar environment near the solar system on cosmic-ray spectra and dipole anisotropy