Dynamical heating across the Milky Way disc using APOGEE and Gaia
Affiliation
Univ Arizona, Dept AstronIssue Date
2019-08-29Keywords
Galaxy: discGalaxy: evolution
Galaxy: formation
Galaxy: kinematics and dynamics
Galaxy: stellar content
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OXFORD UNIV PRESSCitation
J Ted Mackereth, Jo Bovy, Henry W Leung, Ricardo P Schiavon, Wilma H Trick, William J Chaplin, Katia Cunha, Diane K Feuillet, Steven R Majewski, Marie Martig, Andrea Miglio, David Nidever, Marc H Pinsonneault, Victor Silva Aguirre, Jennifer Sobeck, Jamie Tayar, Gail Zasowski, Dynamical heating across the Milky Way disc using APOGEE and Gaia, Monthly Notices of the Royal Astronomical Society, Volume 489, Issue 1, October 2019, Pages 176–195, https://doi.org/10.1093/mnras/stz1521Rights
Copyright © 2019 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
The kinematics of the MilkyWay disc as a function of age arewellmeasured at the solar radius, but have not been studied over a wider range of Galactocentric radii. Here, we measure the kinematics of mono-age, mono-[Fe/H] populations in the low and high [alpha/Fe] discs between 4 less than or similar to R less than or similar to 13 kpc and vertical bar z vertical bar less than or similar to 2 kpc using 65 719 stars in common between APOGEE DR14 and Gaia DR2 for which we estimate ages using a Bayesian neural network model trained on asteroseismic ages. We determine the vertical and radial velocity dispersions, finding that the low and high [alpha/Fe] discs display markedly different age-velocity dispersion relations (AVRs) and shapes sigma(z)/sigma(R). The high [alpha/Fe] disc has roughly flat AVRs and constant sigma(z)/sigma(R) = 0.64 +/- 0.04, whereas the low [alpha/Fe] disc has large variations in this ratio that positively correlate with the mean orbital radius of the population at fixed age. The high [alpha/Fe] disc component's flat AVRs and constant sigma(z)/sigma(R) clearly indicate an entirely different heating history. Outer disc populations also have flatter radial AVRs than those in the inner disc, likely due to thewaning effect of spiral arms. Our detailedmeasurements ofAVRs and sigma(z)/sigma(R) across the disc indicate that low [alpha/Fe], inner disc (R less than or similar to 10 kpc) stellar populations are likely dynamically heated by both giant molecular clouds and spiral arms, while the observed trends for outer disc populations require a significant contribution from another heating mechanism such as satellite perturbations. We also find that outer disc populations have slightly positive mean vertical and radial velocities likely because they are part of the warped disc.ISSN
0035-8711Version
Final published versionSponsors
STFCScience & Technology Facilities Council (STFC); Royal Astronomical Society; Dunlap Institute for Astronomy and Astrophysics at the University of Toronto; ERCEuropean Research Council (ERC) [772293]; Natural Sciences and Engineering Research Council of Canada (NSERC)Natural Sciences and Engineering Research Council of Canada [RGPIN-2015-05235]; Alfred P. Sloan FellowshipAlfred P. Sloan Foundation; NASA through the NASA Hubble Fellowship - Space Telescope Science Institute [51424]; NASANational Aeronautics & Space Administration (NASA) [NAS5-26555]; Royal SocietyRoyal Society of London; LJMU's Faculty of Engineering and Technology; Alfred P. Sloan FoundationAlfred P. Sloan Foundation; U.S. Department of Energy Office of ScienceUnited States Department of Energy (DOE); Center for High-Performance Computing at the University of Utah; Brazilian Participation Group; Carnegie Institution for Science; Carnegie Mellon University; Chilean Participation Group; French Participation Group; Johns Hopkins UniversityJohns Hopkins University; Kavli Institute for the Physics and Mathematics of the Universe (IPMU)/University of Tokyo; Korean Participation Group; Lawrence Berkeley National LaboratoryUnited States Department of Energy (DOE); Leibniz Institut fur Astrophysik Potsdam (AIP); Max-Planck-Institut fur Astronomie (MPIA Heidelberg); Max-Planck-Institut fur Astrophysik (MPA Garching); Max-Planck-Institut fur Extraterrestrische Physik (MPE); National Astronomical Observatories of China; New Mexico State University; NewYork University; University of Notre Dame; Observatario Nacional/MCTI; Ohio State UniversityOhio State University; Pennsylvania State University; Shanghai Astronomical Observatory; United Kingdom Participation Group; Universidad Nacional Autonoma de MexicoUniversidad Nacional Autonoma de Mexico; University of Arizona; University of Colorado Boulder; University of Oxford; University of Portsmouth; University of Utah; University of Virginia; University of WashingtonUniversity of Washington; University of Wisconsin; Vanderbilt University; Yale University; Harvard-Smithsonian Center for AstrophysicsSmithsonian InstitutionHarvard-Smithsonian Center for Astrophysics; Instituto de Astrofisica de CanariasScopus Count
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