The long Galactic bar as seen by UKIDSS Galactic Plane Survey

Abstract

Over the last decade there have been a series of results supporting the hypothesis of the existence of a long thin bar in the Milky Way with a half-length of 4.5 kpc and a position angle of around 45 deg. This is apparently a very different structure from the triaxial bulge of the Galaxy, which is thicker and shorter and dominates the star counts at |l|<10 deg. In this paper, we analyse the stellar distribution in the inner Galaxy to see if there is clear evidence for two triaxial or bar-like structures in the Milky Way. By using the red-clump population as a tracer of Galactic structure, we determine the apparent morphology of the inner Galaxy. Deeper and higher spatial resolution NIR photometry from the UKIDSS Galactic Plane Survey allows us to use in-plane data even at the innermost Galactic longitudes, a region where the source confusion is a dominant effect that makes it impossible to use other NIR databases such as 2MASS or TCS-CAIN. We show that results previously obtained with using the red-clump giants are confirmed with the in-plane data from UKIDSS GPS. There are two different structures coexisting in the inner Galactic plane: one with a position angle of 23.60+-2.19 deg that can be traced from the Galactic Centre up to l=10 deg (the Galactic bulge), and other with a larger position angle of 42.44+-2.14 deg, that ends around l=28 deg (the long Galactic bar).

(8 pages, 14 figures, accepted for publication in A&A)

References in corpus (29)

• The UKIRT Infrared Deep Sky Survey (UKIDSS)
• GLIMPSE: I. A SIRTF Legacy Project to Map the Inner Galaxy
• First GLIMPSE Results on the Stellar Structure of the Galaxy
• The photometric structure of the inner Galaxy
• COBE's Galactic Bar and Disk
• Old stellar Galactic disc in near-plane regions according to 2MASS: scales, cut-off, flare and warp
• Spiral arms, bar shape and bulge microlensing in the Milky Way
• Interstellar Extinction Law in the J, H, and Ks Bands toward the Galactic Center
• Modelling the Galactic Bar Using Red Clump Giants
• K-Band Calibration of the Red Clump Luminosity
• Color-Magnitude Diagram Distribution of the Bulge Red Clump Stars - Evidence for the Galactic Bar
• Population effects on the red giant clump absolute magnitude: The K-band
• The structure of the Galactic bar
• Detection of the old stellar component of the major Galactic bar
• Infrared stellar populations in the central parts of the Milky Way galaxy
• WIYN Open Cluster Study. X. The K-Band Magnitude of the Red Clump as a Distance Indicator
• Tracing the long bar with red-clump giants
• High Mass Starless Cores
• The Long Bar in the Milky Way. Corroboration of an old hypothesis
• A Distinct Structure Inside the Galactic Bar
• A boxy bulge in the Milky Way. Inversion of the stellar statistics equation with 2MASS data
• The red clump absolute magnitude based on revised Hipparcos parallaxes
• The Distance to the Galactic Center Derived From Infrared Photometry of Bulge Red Clump Stars
• New constraints on a triaxial model of the Galaxy
• Searching for the in-plane Galactic bar and ring in DENIS
• Inversion of stellar statistics equation for the Galactic Bulge
• Evidence for a deficit of young and old stars in the Milky Way inner in-plane disc
• Estimation of Galactic model parameters in high latitudes with 2MASS
• Stellar density distribution in the NIR on the Galactic plane at longitudes 15-27 deg. Clues for the Galactic bar ?

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• The Galaxy in Context: Structural, Kinematic and Integrated Properties
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• ARGOS III: Stellar Populations in the Galactic Bulge of the Milky Way
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• The Split Red Clump of the Galactic Bulge from OGLE-III
• Chemodynamical history of the Galactic Bulge
• Made-to-Measure models of the Galactic Box/Peanut bulge: stellar and total mass in the bulge region
• The GIRAFFE Inner Bulge Survey (GIBS). I. Survey Description and a kinematical map of the Milky Way bulge
• Galactic Stellar Populations in the Era of SDSS and Other Large Surveys
• Unifying boxy bulge and planar long bar in the Milky Way
• Reddening and metallicity maps of the Milky Way bulge from VVV and 2MASS III. The first global photometric metallicity map of the Galactic bulge
• The H2O southern Galactic Plane Survey(HOPS): NH3 (1,1) and (2,2) catalogues
• Kinematics of massive star ejecta in the Milky Way as traced by 26Al
• On the nature of the barlens component in barred galaxies: what do boxy/peanut bulges look like when viewed face-on?
• Gas dynamics in the Milky Way: a low pattern speed model
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• Chemodynamical Modelling of the Galactic Bulge and Bar
• Gas Dynamics in the Galaxy: Total Mass Distribution and the Bar Pattern Speed
• OGLE-III Detection of the Anomalous Galactic Bulge Red Giant Branch Bump: Evidence of Enhanced Helium Enrichment
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• On the Spiral Structure of the Milky Way Galaxy
• 3D kinematics through the X-shaped Milky Way bulge
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• The Information Of The Milky Way From 2MASS Whole Sky Star Count: The Structure Parameters
• Modelling the inner disc of the Milky Way with manifolds. I - A first step
• Stellar halo substructure generated by bar resonances
• Dynamically constraining the length of the Milky Way bar
• A Galaxy Model from 2MASS Star Counts in the Whole Sky Including the Plane
• Dynamics for Galactic Archaeology
• Fabry-Perot Absorption Line Spectroscopy of the Galactic Bar. I. Kinematics
• The Hercules stream as seen by APOGEE-2 South
• A third cluster of red supergiants in the vicinity of the massive cluster RSGC3
• Constraining the Galactic structure parameters with the XSTPS-GAC and SDSS photometric surveys
• Quantifying the (X/peanut)-shaped Structure of the Milky Way - New Constraints on the Bar Geometry
• A three-dimensional map of the Milky Way using 66,000 Mira variable stars
• The Distances of the Galactic Novae
• From the Outside Looking in: What can Milky Way Analogues Tell us About the Star Formation Rate of Our Own Galaxy?
• The Blanco DECam Bulge Survey. I. The Survey Description and Early Results
• The chemistry of stars in the bar of the Milky Way
• 3-Dimensional Kinematics in low foreground extinction windows of the Galactic Bulge: Radial Velocities for 6 bulge fields
• A Galactic Ring of Minimum Stellar Density Near the Solar Orbit Radius
• N-body simulations in reconstruction of the kinematics of young stars in the Galaxy
• Multiwavelength observations of the black hole transient XTE J1752-223 during its 2010 outburst decay
• Near-infrared spectroscopy of candidate red supergiant stars in clusters
• Near-infrared photometry and spectroscopy of the low Galactic latitude globular cluster 2MASS-GC03
• GalMod: a Galactic synthesis population model
• The Dynamical Response of Dark Matter to Galaxy Evolution Affects Direct-Detection Experiments
• Towards a three-dimensional distribution of the molecular clouds in the Galactic Centre
• WR 120bb and WR 120bc: a pair of WN9h stars with possibly interacting circumstellar shells
• Infrared extinction in the Inner Milky Way through the red clump giants
• Impact of distance determinations on Galactic structure. II. Old tracers
• Luminosity-Colour Relations for Red Clump Stars
• FEDReD I: 3D extinction and stellar maps by Bayesian deconvolution
• A radiation transfer model for the Milky Way. II The global properties and large scale structure
• Double X/Peanut Structures in Barred Galaxies -- Insights from an $N$--body Simulation
• Comparing Observed Stellar Kinematics and Surface Densities in a Low Latitude Bulge Field to Galactic Population Synthesis Models
• Measuring the Streaming motion in the Milky Way disc with Gaia EDR3 +
• Absolute Magnitude Calibration for Red Clump Stars
• Three-dimensional decomposition of galaxies with bulge and long bar
• Transformations between 2MASS, SDSS and BVI photometric systems for late-type giants
• The Expanding 3 kpc Arms Are Neither Expanding nor Spiral Arms but X1 Orbits Driven by the Galactic Bar
• The Galactic Bar
• Distance and extinction to the Milky Way spiral arms along the Galactic centre line of sight