تقرير
The Age-Dependent Vertical Actions of Young Stars in the Galaxy
| العنوان: | The Age-Dependent Vertical Actions of Young Stars in the Galaxy |
|---|---|
| المؤلفون: | Garzon, D. N., Frankel, Neige, Zari, Eleonora, Xiang, Maosheng, Rix, Hans-Walter |
| سنة النشر: | 2024 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Astrophysics of Galaxies |
| الوصف: | Stars in the Galactic disk are born on cold, nearly circular orbits with small vertical excursions. After their birth, their orbits evolve, driven by small- or large-scale perturbations in the Galactic disk's gravitational potential. Here, we study the vertical motions of young stars over their first few orbital periods, using a sample of OBA stars from \textit{Gaia} E/DR3, which includes radial velocities and ages $\tau$ from LAMOST. We constructed a parametric model for the time evolution of the stellar orbits' mean vertical actions $J_z$ as a function of Galactocentric radius, $R_{\mathrm{GC}}$. Accounting for data uncertainties, we use Markov Chain Monte Carlo (MCMC) analysis in annuli of Galactocentric radius to constrain the model parameters. Our best-fit model shows a remarkably linear increase of vertical actions with age across all Galactocentric radii examined. Orbital \textit{heating} by random scattering could offer a straightforward interpretation for this trend. However, various other dynamical aspects of the Galactic disk, such as stars being born in a warped disk, might offer alternative explanations that could be tested in the future. Comment: 10 pages, 5 figures. Draft version July 9, 2024. Typeset using LATEX default style in AASTeX631 |
| نوع الوثيقة: | Working Paper |
| URL الوصول: | http://arxiv.org/abs/2407.07323 |
| رقم الأكسشن: | edsarx.2407.07323 |
| قاعدة البيانات: | arXiv |
| الوصف غير متاح. |