A three-dimensional map of the Milky Way using 66,000 Mira variable stars

Abstract

We study the three-dimensional structure of the Milky Way using 65,981 Mira variable stars discovered by the Optical Gravitational Lensing Experiment (OGLE) survey. The spatial distribution of the Mira stars is analyzed with a model containing three barred components that include the X-shaped boxy component in the Galactic center (GC), and an axisymmetric disk. We take into account the distance uncertainties by implementing the Bayesian hierarchical inference method. The distance to the GC is $R_0=7.66\pm 0.01(stat.)\pm 0.39(sys.)$ kpc, while the inclination of the major axis of the bulge to the Sun-GC line-of-sight is $\theta =20.2^{\circ }\pm 0.6^{\circ }(stat.)\pm 0.7^{\circ }(sys.)$. We present, for the first time, a detailed three-dimensional map of the Milky Way composed of young and intermediate-age stellar populations. Our analysis provides independent evidence for both the X-shaped bulge component and the flaring disk (being plausibly warped). We provide the complete dataset of properties of Miras that were used for calculations in this work. The table includes: mean brightness and amplitudes in nine photometric bands (covering a range of wavelength from 0.5 to 12 $\mu$m), photometric chemical type, estimated extinction, and calculated distance with its uncertainty for each Mira variable. The median distance accuracy to a Mira star is at the level of $6.6\%$.

Accepted for publication in The Astrophysical Journal Supplement Series. 22 pages, 7 figures, 2 tables. The full machine readable Table 1 and corner plot are available through the OGLE website via https://www.astrouw.edu.pl/ogle/ogle4/MILKY_WAY_3D_MAP/, and Zenodo via https://doi.org/10.5281/zenodo.7472598

References in corpus (35)

• The Gaia mission
• The Zwicky Transient Facility: System Overview, Performance, and First Results
• Initial Performance of the NEOWISE Reactivation Mission
• Two Stellar Components in the Halo of the Milky Way
• The Optical to Mid-Infrared Extinction Law Based on the APOGEE, Gaia DR2, Pan-STARRS1, SDSS, APASS, 2MASS and WISE Surveys
• Dynamical modelling of the Galactic bulge and bar: the Milky Way's bar pattern speed, stellar, and dark matter mass distribution
• Outer structure of the Galactic warp and flare: explaining the Canis Major over-density
• Exoplanet population inference and the abundance of Earth analogs from noisy, incomplete catalogs
• The Spiral Structure of the Outer Milky Way in Hydrogen
• Near-Infrared Photometry of Carbon Stars
• An intuitive 3D map of the Galactic warp's precession traced by classical Cepheids
• Kinematics of the old stellar population at the Galactic Center
• The Long Bar in the Milky Way. Corroboration of an old hypothesis
• The long Galactic bar as seen by UKIDSS Galactic Plane Survey
• Chemical evolution of the Milky Way: constraints on the formation of the thick and thin discs
• The age of the Milky Way inner stellar spheroid from RR Lyrae population synthesis
• The Bulge Radial Velocity Assay for RR Lyrae stars (BRAVA-RR) DR2: a Bimodal Bulge?
• The stellar mass distribution of the Milky Way's bar: an analytic model
• Age Demographics of the Milky Way Disk and Bulge
• Large Magellanic Cloud Near-Infrared Synoptic Survey. V. Period-Luminosity Relations of Miras
• 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
• Quantifying the (X/peanut)-shaped Structure of the Milky Way - New Constraints on the Bar Geometry
• The M33 Synoptic Stellar Survey. II. Mira Variables
• Absence of an X-shaped Structure in the Milky Way Bulge Using Mira Variable Stars
• Mira variables in the Milky Way's nuclear stellar disc: discovery and classification
• Discovery of carbon-rich Miras in the Galactic bulge
• Multiwavelength properties of Miras
• Trigonometric Distance and Proper Motion of IRAS 20056+3350: Massive Star Forming Region on the Solar Circle
• Age-morphology dependence of the Milky Way boxy/peanut bulge seen in Mira variables
• Differential rotation of the halo traced by the K-giant stars
• The small boxy/peanut structure of the Milky Way traced by old stars
• Distribution of red clump stars does not support the X-shaped Galactic bulge
• The global structure of the Milky Way's stellar halo based on the orbits of local metal-poor stars
• Analysing the structure of the bulge with Mira variables

Cited by in corpus (6)

• The CosmoVerse White Paper: Addressing observational tensions in cosmology with systematics and fundamental physics
• The far side of the Galactic bar/bulge revealed through semi-regular variables
• RR Lyrae stars trace the Milky Way warp
• Unveiling VVV/WISE Mira variables on the far side of the Galactic disk: Distances, kinematics and a new extinction law
• Long-period maser-bearing Miras in the Galactic center: period-luminosity relations and extinction estimates
• The Variable Sky Through the OGLE Eye