Reddening and metallicity maps of the Milky Way bulge from VVV and 2MASS III. The first global photometric metallicity map of the Galactic bulge

Abstract

We investigate the large scale metallicity distribution in the Galactic bulge, using a large spatial coverage, in order to constrain the bulge formation scenario. We use the VISTA variables in the Via Lactea (VVV) survey data and 2MASS photometry, covering 320 sqdeg of the Galactic bulge, to derive photometric metallicities by interpolating of the (J-Ks)0 colors of individual Red Giant Branch stars based on a set of globular cluster ridge lines. We then use this information to construct the first global metallicity map of the bulge with a resolution of 30'x45'. The metallicity map of the bulge revealed a clear vertical metallicity gradient of ~0.04 dex/deg (~0.28 dex/kpc), with metal-rich stars ([Fe/H]~0) dominating the inner bulge in regions closer to the galactic plane (|b|<5). At larger scale heights, the mean metallicity of the bulge population becomes significantly more metal-poor. This fits in the scenario of a boxy-bulge originated from the vertical inestability of the Galactic bar, formed early via secular evolution of a two component stellar disk. Older, metal-poor stars dominate at higher scale heights due to the non-mixed orbits from the originally hotter thick disk stars.

Accepted for publication in A&A

References in corpus (20)

• Mass and environment as drivers of galaxy evolution in SDSS and zCOSMOS and the origin of the Schechter function
• From rings to bulges: evidence for rapid secular galaxy evolution at z~2 from integral field spectroscopy in the SINS survey
• Reddening and Extinction Toward the Galactic Bulge from OGLE-III: The Inner Milky Way's Rv ~ 2.5 Extinction Curve
• Structural Properties of Pseudo-Bulges, Classical Bulges and Elliptical Galaxies: an SDSS Perspective
• The rapid formation a large rotating disk galaxy three billion years after the Big Bang
• Bulge Formation by the Coalescence of Giant Clumps in Primordial Disk Galaxies
• Chemical similarities between Galactic bulge and local thick disk red giant stars
• The origin of the split red clump in the Galactic bulge of the Milky Way
• Near-IR properties of 24 Globular Clusters in the Galactic Bulge
• Modelling the Galactic bar using OGLE-II Red Clump Giant Stars
• K-Band Observations of Boxy Bulges. I. Morphology and Surface Brightness Profiles
• Tracing the long bar with red-clump giants
• The First Detailed Abundances for M giants in the inner Bulge from Infrared Spectroscopy
• The long Galactic bar as seen by UKIDSS Galactic Plane Survey
• Constraining the structure and formation of the Galactic bulge from a field in its outskirts. FLAMES-GIRAFFE spectra of about 400 red giants around (l,b)=(0°,-10°)
• Old and young bulges in late-type disk galaxies
• The complex, variable near infrared extinction towards the Nuclear Bulge
• Chemical evolution of the Galactic bulge: different stellar populations and possible gradients
• Stellar Population Gradients in Bulges along the Hubble Sequence: II. Relations with Galaxy Properties
• The Evolutionary History of Galactic Bulges: Photometric and Spectroscopic Studies of Distant Spheroids in the GOODS Fields

Cited by in corpus (78)

• The Galaxy in Context: Structural, Kinematic and Integrated Properties
• Chemical Cartography with APOGEE: Metallicity Distribution Functions and the Chemical Structure of the Milky Way Disk
• Mapping the Three-Dimensional Density of the Galactic Bulge with VVV Red Clump Stars
• Mass and shape of the Milky Way's dark matter halo with globular clusters from Gaia and Hubble
• Chemodynamical history of the Galactic Bulge
• Chemical evolution of the Galactic bulge as traced by microlensed dwarf and subgiant stars. VI. Age and abundance structure of the stellar populations in the central sub-kpc of the Milky Way
• Chemical Cartography with APOGEE: Large-scale Mean Metallicity Maps of the Milky Way
• The GIRAFFE Inner Bulge Survey (GIBS) III. Metallicity distributions and kinematics of 26 Galactic bulge fields
• The Gaia-ESO Survey: metallicity and kinematic trends in the Milky Way bulge
• VVV Survey Near-Infrared Photometry of Known Bulge RR Lyrae stars: the Distance to the Galactic Center and Absence of a Barred Distribution of the Metal-Poor Population
• The GIRAFFE Inner Bulge Survey (GIBS). I. Survey Description and a kinematical map of the Milky Way bulge
• The Gaia-ESO Survey: Exploring the complex nature and origins of the Galactic bulge populations
• Interstellar Extinction Curve Variations Toward the Inner Milky Way: A Challenge to Observational Cosmology
• The Milky Way bar and bulge revealed by APOGEE DR16 and Gaia EDR3
• The EMBLA Survey -- Metal-poor stars in the Galactic bulge
• Mapping the Milky Way bulge at high resolution: the 3D dust extinction, CO, and X factor maps
• Extinction ratios in the inner Galaxy as revealed by the VVV survey
• The disc origin of the Milky Way bulge: Dissecting the chemo-morphological relations using N-body simulations and APOGEE
• How Many Components? Quantifying the Complexity of the Metallicity Distribution in the Milky Way Bulge with APOGEE
• Why the Milky Way's bulge is not only a bar formed from a cold thin disk
• APOGEE Kinematics I: Overview of the Kinematics of the Galactic Bulge as Mapped by APOGEE
• The Gaia-ESO Survey: the most metal-poor stars in the Galactic bulge
• A parametric description of the 3D structure of the Galactic Bar/Bulge using the VVV survey
• The Giraffe Inner Bulge Survey (GIBS) II. Metallicity distributions and alpha element abundances at fixed Galactic latitude
• Stellar Ages through the Corners of the Boxy Bulge
• Mapping a stellar disk into a boxy bulge: The outside-in part of the Milky Way bulge formation
• Mapping the outer bulge with RRab stars from the VVV Survey
• The inner two degrees of the Milky Way. Evidence of a chemical difference between the Galactic Center and the surrounding inner bulge stellar populations
• Formation, vertex deviation and age of the Milky Way's bulge: input from a cosmological simulation with a late-forming bar
• Transverse kinematics of the Galactic bar-bulge from VVV and Gaia
• The Bulge Metallicity Distribution from the APOGEE Survey
• Mapping the stellar age of the Milky Way bulge with the VVV. III. High resolution reddening map
• Chemical evolution of the inner 2 degrees of the Milky Way bulge: [alpha/Fe] trends and metallicity gradients
• The Metallicity Distribution of the Milky Way Bulge
• Star formation history and metallicity in the Galactic inner bulge revealed by the red giant branch bump
• MOA-2016-BLG-227Lb: A Massive Planet Characterized by Combining Lightcurve Analysis and Keck AO Imaging
• The structure behind the Galactic bar traced by red clump stars in the VVV survey
• The VISTA Variables in the Vía Láctea eXtended (VVVX) ESO public survey: Completion of the observations and legacy
• GALACTICNUCLEUS: A high-angular-resolution $JH{K}_s$ imaging survey of the Galactic centre. IV. Extinction maps and de-reddened photometry
• The stellar populations of the central region of M31
• Box/peanut-shaped bulges in action space
• The VVV Templates Project. Towards an Automated Classification of VVV Light-Curves. I. Building a database of stellar variability in the near-infrared
• High-precision astrometry with VVV. I. An independent reduction pipeline for VIRCAM@VISTA
• The Optical/Near-Infrared Extinction Law In Highly Reddened Regions
• Galactic Bulge Population II Cepheids in the VVV Survey: Period-Luminosity Relations and a Distance to the Galactic Center
• Blanco DECam Bulge Survey (BDBS) II: Project Performance, Data Analysis, and Early Science Results
• What the Milky Way bulge reveals about the initial metallicity gradients in the disc
• The central spheroids of Milky Way mass-sized galaxies
• Stars behind bars II: A cosmological formation scenario for the Milky Way's central stellar structure
• New insight on the origin of the double red clump in the Milky Way bulge
• The Milky Way Bulge: Observed properties and a comparison to external galaxies
• Reinforcing the link between the double red clump and the X-shaped bulge of the Milky Way
• A KMOS survey of the nuclear disk of the Milky Way I: Survey design and metallicities
• An extremely low mid-infrared extinction law toward the Galactic Center and 4% distance precision to 55 classical Cepheids
• The age distribution of stars in the Milky Way bulge
• The extinction law in the inner $3\times 3$ deg${}^2$ of the Milky Way and the red clump absolute magnitude in the inner bar-bulge
• The structure of the Milky Way based on unWISE 3.4$\mu$m integrated photometry
• Milky Way demographics with the VVV Survey III. Evidence for a Great Dark Lane in the 157 Million Star Bulge Color-Magnitude Diagram
• Temperatures and metallicities of M giants in the galactic Bulge from low-resolution K-band spectra
• Theoretical Models of the Galactic Bulge
• Near-Infrared Structure of Fast and Slow Rotating Disk Galaxies
• Barlenses in the CALIFA survey: combining the photometric and stellar population analysis
• Comparing the properties of the X-shaped bulges of NGC 4710 and the Milky Way with MUSE
• Candidate star clusters toward the inner Milky Way discovered on deep-stacked Ks-band images from the VVV Survey
• Peanut-shaped metallicity distributions in bulges of edge-on galaxies: the case of NGC 4710
• Difference in chemical composition between the bright and faint red clump stars in the Milky Way bulge
• Mapping the tilt of the Milky Way bulge velocity ellipsoids with ARGOS and $Gaia$ DR2
• Study of extremely reddened AGB stars in the Galactic bulge
• Mapping the stellar age of the Milky Way bulge with the VVV. II. Deep JKs catalogs release based on PSF photometry
• Astrometry in crowded fields towards the Galactic Bulge
• ELT-MOS White Paper: Science Overview & Requirements
• Time-Series Surveys and Pulsating Stars: The Near-Infrared Perspective
• Metallicity Properties of the Galactic Bulge Stars Near and Far: Expectations from the Auriga Simulation
• The multi-zone chemical evolution of the Galactic bulge: predicting abundances for different radial zones
• Rediscovering the Milky Way with orbit superposition approach and APOGEE data III. Panoramic view of the bulge
• A Near-Infrared Extinction and Reddening Map Towards the Galactic Bulge Using UKIRT
• The Two-infall Model Revisited: Constraints on Milky Way Bulge Assembly from >30,000 Galactic Chemical Evolution Models and Machine Learning
• Blanco DECam Bulge Survey (BDBS) IV: Metallicity Distributions and Bulge Structure from 2.6 Million Red Clump Stars