Deciphering the evolution of the Milky Way discs: The Gaia APOGEE Kepler giant stars & Besanc{c}on Galaxy Model. (arXiv:2106.15616v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Lagarde_N/0/1/0/all/0/1">N. Lagarde</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Reyle_C/0/1/0/all/0/1">C. Reylé</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chiappini_C/0/1/0/all/0/1">C. Chiappini</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mor_R/0/1/0/all/0/1">R. Mor</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Anders_F/0/1/0/all/0/1">F. Anders</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Figueras_F/0/1/0/all/0/1">F. Figueras</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Miglio_A/0/1/0/all/0/1">A. Miglio</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Romero_Gomez_M/0/1/0/all/0/1">M. Romero-Gómez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Antoja_T/0/1/0/all/0/1">T. Antoja</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cabral_N/0/1/0/all/0/1">N. Cabral</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Salomon_J/0/1/0/all/0/1">J.-B. Salomon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Robin_A/0/1/0/all/0/1">A.C. Robin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bienayme_O/0/1/0/all/0/1">O. Bienaymé</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Soubiran_C/0/1/0/all/0/1">C. Soubiran</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cornu_D/0/1/0/all/0/1">D. Cornu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Montillaud_J/0/1/0/all/0/1">J. Montillaud</a>
We investigate the properties of the double sequences of the Milky Way discs
visible in the [$alpha$/Fe] vs [Fe/H] diagram. In the framework of Galactic
formation and evolution, we discuss the complex relationships between age,
metallicity, [$alpha$/Fe], and the velocity components. We study stars with
measured chemical, seismic and astrometric properties from the APOGEE survey,
the Kepler and Gaia satellites, respectively. We separate the
[$alpha$/Fe]-[Fe/H] diagram into 3 stellar populations: the thin disc,
high-$alpha$ metal-poor thick disc and high-$alpha$ metal-rich thick disc and
characterise each of these in the age-chemo-kinematics parameter space. We
compare results obtained from different APOGEE data releases and using two
recent age determinations. We use the Besanc{c}on Galaxy model (BGM) to
highlight selection biases and mechanisms not included in the model. The thin
disc exhibits a flat age-metallicity relation while [$alpha$/Fe] increases
with stellar age. We confirm no correlation between radial and vertical
velocities with [Fe/H], [$alpha$/Fe] and age for each stellar population.
Considering both samples, V$_varphi$ decreases with age for the thin disc,
while it is in the opposite direction for the h$alpha$mp thick disc. Although
the age distribution of the h$alpha$mr thick disc is very close to that of the
h$alpha$mp thick disc between 7 and 14 Gyr, its kinematics seems to follow the
thin disc kinematics. This feature, not predicted by the hypotheses included in
the BGM, suggests a different origin and history of this population. Finally,
we show a maximum of the dispersion of the vertical velocity, $sigma_Z$, with
age for the h$alpha$mp thick disc around 8 Gyr. The comparisons with the BGM
simulations suggest a more complex chemo-dynamical scheme to explain this
feature, most likely including mergers and radial migration effects
We investigate the properties of the double sequences of the Milky Way discs
visible in the [$alpha$/Fe] vs [Fe/H] diagram. In the framework of Galactic
formation and evolution, we discuss the complex relationships between age,
metallicity, [$alpha$/Fe], and the velocity components. We study stars with
measured chemical, seismic and astrometric properties from the APOGEE survey,
the Kepler and Gaia satellites, respectively. We separate the
[$alpha$/Fe]-[Fe/H] diagram into 3 stellar populations: the thin disc,
high-$alpha$ metal-poor thick disc and high-$alpha$ metal-rich thick disc and
characterise each of these in the age-chemo-kinematics parameter space. We
compare results obtained from different APOGEE data releases and using two
recent age determinations. We use the Besanc{c}on Galaxy model (BGM) to
highlight selection biases and mechanisms not included in the model. The thin
disc exhibits a flat age-metallicity relation while [$alpha$/Fe] increases
with stellar age. We confirm no correlation between radial and vertical
velocities with [Fe/H], [$alpha$/Fe] and age for each stellar population.
Considering both samples, V$_varphi$ decreases with age for the thin disc,
while it is in the opposite direction for the h$alpha$mp thick disc. Although
the age distribution of the h$alpha$mr thick disc is very close to that of the
h$alpha$mp thick disc between 7 and 14 Gyr, its kinematics seems to follow the
thin disc kinematics. This feature, not predicted by the hypotheses included in
the BGM, suggests a different origin and history of this population. Finally,
we show a maximum of the dispersion of the vertical velocity, $sigma_Z$, with
age for the h$alpha$mp thick disc around 8 Gyr. The comparisons with the BGM
simulations suggest a more complex chemo-dynamical scheme to explain this
feature, most likely including mergers and radial migration effects
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