Ages & [Fe/H] of the MW bulge using APOGEE Virtual Observatory Resource

Authors
  1. Hasselquist S.
  2. Zasowski G.
  3. Feuillet D.K.
  4. Schultheis M.,Nataf D.M.
  5. Anguiano B.
  6. Beaton R.L.
  7. Beers T.C.
  8. Cohen R.E.
  9. Cunha K.,Fernandez-Trincado J.G.
  10. Garcia-Hernandez D.A.
  11. Geisler D.
  12. Holtzman J.A.,Johnson J.
  13. Lane R.R.
  14. Majewski S.R.
  15. Moni Bidin C.
  16. Nitschelm C.,Roman-Lopes A.
  17. Schiavon R.
  18. Smith V.V.
  19. Sobeck J.
  20. Published by
    CDS
Abstract

We present stellar age distributions of the Milky Way bulge region using ages for ~6000 high-luminosity (log(g)<2.0), metal-rich ([Fe/H]>=-0.5) bulge stars observed by the Apache Point Observatory Galactic Evolution Experiment. Ages are derived using The Cannon label-transfer method, trained on a sample of nearby luminous giants with precise parallaxes for which we obtain ages using a Bayesian isochrone-matching technique. We find that the metal-rich bulge is predominantly composed of old stars (>8Gyr). We find evidence that the planar region of the bulge (|Z_GC_|<=0.25kpc) is enriched in metallicity, Z, at a faster rate (dZ/dt~0.0034Gyr^-1^) than regions farther from the plane (dZ/dt~0.0013Gyr^-1^ at |Z_GC_|>1.00kpc). We identify a nonnegligible fraction of younger stars (age ~2-5Gyr) at metallicities of +0.2<[Fe/H]<+0.4. These stars are preferentially found in the plane (|Z_GC_|<=0.25kpc) and at R_cy_~2-3kpc, with kinematics that are more consistent with rotation than are the kinematics of older stars at the same metallicities. We do not measure a significant age difference between stars found inside and outside the bar. These findings show that the bulge experienced an initial starburst that was more intense close to the plane than far from the plane. Then, star formation continued at supersolar metallicities in a thin disk at 2kpc<~R_cy_<~3kpc until ~2Gyr ago.

Keywords
  1. milky-way-galaxy
  2. metallicity
  3. stellar-ages
  4. infrared-astronomy
  5. spectroscopy
Bibliographic source Bibcode
2020ApJ...901..109H
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/901/109
IVOA Identifier IVOID
ivo://CDS.VizieR/J/ApJ/901/109
Document Object Identifer DOI
doi:10.26093/cds/vizier.19010109

Access

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http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/901/109
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History

2022-02-18T13:28:59Z
Resource record created
2022-02-18T13:28:59Z
Created
2023-02-17T16:11:49Z
Updated

Contact

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CDS support team
Postal Address
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