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Spatial variations in the Milky Way disc metallicity-age relation

Feuillet, Diane LU ; Frankel, Neige ; Lind, Karin ; Frinchaboy, Peter ; Garcia-Hernandez, D A ; Lane, Richard ; Nitschem, Christian and Roman-Lopes, Alexandre (2019) In Monthly Notices of the Royal Astronomical Society 489(2). p.1742-1752
Abstract
Stellar ages are a crucial component to studying the evolution of the Milky Way. Using Gaia DR2 distance estimates, it is now possible to estimate stellar ages for a larger volume of evolved stars through isochrone matching. This work presents [M/H]-age and [α/M]-age relations derived for different spatial locations in the Milky Way disc. These relations are derived by hierarchically modelling the star formation history of stars within a given chemical abundance bin. For the first time, we directly observe that significant variation is apparent in the [M/H]-age relation as a function of both Galactocentric radius and distance from the disc mid-plane. The [M/H]-age relations support claims that radial migration has a significant effect in... (More)
Stellar ages are a crucial component to studying the evolution of the Milky Way. Using Gaia DR2 distance estimates, it is now possible to estimate stellar ages for a larger volume of evolved stars through isochrone matching. This work presents [M/H]-age and [α/M]-age relations derived for different spatial locations in the Milky Way disc. These relations are derived by hierarchically modelling the star formation history of stars within a given chemical abundance bin. For the first time, we directly observe that significant variation is apparent in the [M/H]-age relation as a function of both Galactocentric radius and distance from the disc mid-plane. The [M/H]-age relations support claims that radial migration has a significant effect in the plane of the disc. Using the [M/H] bin with the youngest mean age at each radial zone in the plane of the disc, the present-day metallicity gradient is measured to be -0.059 ± 0.010 dex/kpc, in agreement with Cepheids and young field stars. We find a vertically flared distribution of young stars in the outer disc, confirming predictions of models and previous observations. The mean age of the [M/H]-[α/M] distribution of the solar neighbourhood suggests that the high-[M/H] stars are not an evolutionary extension of the low-α sequence. Our observational results are important constraints to Galactic simulations and models of chemical evolution. (Less)
Please use this url to cite or link to this publication:
author
publishing date
type
Contribution to journal
publication status
published
keywords
Galaxy: abundances, Galaxy: disc, Galaxy: evolution, Galaxy: stellar content, Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics
in
Monthly Notices of the Royal Astronomical Society
volume
489
issue
2
article number
10.1093/mnras/stz2221
pages
12 pages
publisher
Oxford University Press
external identifiers
  • scopus:85075123289
ISSN
1365-2966
DOI
10.1093/mnras/stz2221
language
English
LU publication?
no
id
137b25ac-50f2-43d5-bd36-2ec80725ff8b
date added to LUP
2019-11-27 10:35:10
date last changed
2020-08-05 05:37:18
@article{137b25ac-50f2-43d5-bd36-2ec80725ff8b,
  abstract     = {Stellar ages are a crucial component to studying the evolution of the Milky Way. Using Gaia DR2 distance estimates, it is now possible to estimate stellar ages for a larger volume of evolved stars through isochrone matching. This work presents [M/H]-age and [α/M]-age relations derived for different spatial locations in the Milky Way disc. These relations are derived by hierarchically modelling the star formation history of stars within a given chemical abundance bin. For the first time, we directly observe that significant variation is apparent in the [M/H]-age relation as a function of both Galactocentric radius and distance from the disc mid-plane. The [M/H]-age relations support claims that radial migration has a significant effect in the plane of the disc. Using the [M/H] bin with the youngest mean age at each radial zone in the plane of the disc, the present-day metallicity gradient is measured to be -0.059 ± 0.010 dex/kpc, in agreement with Cepheids and young field stars. We find a vertically flared distribution of young stars in the outer disc, confirming predictions of models and previous observations. The mean age of the [M/H]-[α/M] distribution of the solar neighbourhood suggests that the high-[M/H] stars are not an evolutionary extension of the low-α sequence. Our observational results are important constraints to Galactic simulations and models of chemical evolution.},
  author       = {Feuillet, Diane and Frankel, Neige and Lind, Karin and Frinchaboy, Peter and Garcia-Hernandez, D A and Lane, Richard and Nitschem, Christian and Roman-Lopes, Alexandre},
  issn         = {1365-2966},
  language     = {eng},
  number       = {2},
  pages        = {1742--1752},
  publisher    = {Oxford University Press},
  series       = {Monthly Notices of the Royal Astronomical Society},
  title        = {Spatial variations in the Milky Way disc metallicity-age relation},
  url          = {http://dx.doi.org/10.1093/mnras/stz2221},
  doi          = {10.1093/mnras/stz2221},
  volume       = {489},
  year         = {2019},
}