{
  "id": "1711.03643",
  "version": "v1",
  "published": "2017-11-09T23:21:30.000Z",
  "updated": "2017-11-09T23:21:30.000Z",
  "title": "The temporal evolution of neutron-capture elements in the Galactic discs",
  "authors": [
    "Lorenzo Spina",
    "Jorge Meléndez",
    "Amanda I. Karakas",
    "Leonardo dos Santos",
    "Megan Bedell",
    "Martin Asplund",
    "Ivan Ramírez",
    "David Yong",
    "Alan Alves-Brito",
    "Jacob L. Bean",
    "Stefan Dreizler"
  ],
  "categories": [
    "astro-ph.SR",
    "astro-ph.GA"
  ],
  "abstract": "Important insights into the formation and evolution of the Galactic disc(s) are contained in the chemical compositions of stars. We analysed high-resolution and high signal to noise HARPS spectra of 79 solar twin stars in order to obtain precise determinations of their atmospheric parameters, ages ($\\sigma$$\\sim$0.4 Gyr) and chemical abundances ($\\sigma$$<$0.01~dex) of 12 neutron-capture elements (Sr, Y, Zr, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, and Dy). This valuable dataset allows us to study the [X/Fe]-age relations over a time interval of $\\sim$10 Gyr and among stars belonging to the thin and thick discs. These relations show that i) the $s$-process has been the main channel of nucleosynthesis of $n$-capture elements during the evolution of the thin disc; ii) the thick disc is rich in $r$-process elements which suggests that its formation has been rapid and intensive. %; iii) a chemical continuity between the thin and thick discs is evident in the abundances of Ba. In addition, the heavy (Ba, La, Ce) and light (Sr, Y, Zr) $s$-process elements revealed details on the dependence between the yields of AGB stars and the stellar mass or metallicity. Finally, we confirmed that both [Y/Mg] and [Y/Al] ratios can be employed as stellar clocks, allowing ages of solar twin stars to be estimated with an average precision of $\\sim$0.5~Gyr.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2017-11-09T23:21:30.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "galactic disc",
      "neutron-capture elements",
      "temporal evolution",
      "noise harps spectra",
      "solar twin stars"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}