{
  "id": "2405.00096",
  "version": "v1",
  "published": "2024-04-30T18:00:01.000Z",
  "updated": "2024-04-30T18:00:01.000Z",
  "title": "Pristine Inner Galaxy Survey (PIGS) IX. The largest detailed chemical analysis of very metal-poor stars in the Sagittarius dwarf galaxy",
  "authors": [
    "Federico Sestito",
    "Sara Vitali",
    "Paula Jofre",
    "Kim A. Venn",
    "David S. Aguado",
    "Claudia Aguilera-Gómez",
    "Anke Ardern-Arentsen",
    "Danielle de Brito Silva",
    "Raymond Carlberg",
    "Camilla J. L. Eldridge",
    "Felipe Gran",
    "Vanessa Hill",
    "Pascale Jablonka",
    "Georges Kordopatis",
    "Nicolas F. Martin",
    "Tadafumi Matsuno",
    "Samuel Rusterucci",
    "Else Starkenburg",
    "Akshara Viswanathan"
  ],
  "comment": "Submitted to A&A",
  "categories": [
    "astro-ph.GA",
    "astro-ph.SR"
  ],
  "abstract": "The most metal-poor stars provide valuable insights into the early chemical enrichment history of a system, carrying the chemical imprints of the first generations of supernovae. The most metal-poor region of the Sagittarius dwarf galaxy remains inadequately observed and characterised. To date, only a handful of stars with [Fe/H]$<-2.0$ have been chemically analysed with high-resolution spectroscopy. In this study, we present the most extensive chemical abundance analysis of 12 low-metallicity stars with metallicities down to [Fe/H]$=-3.26$ and located in the main body of Sagittarius. These targets, selected from the Pristine Inner Galaxy survey, were observed using the MIKE high-resolution spectrograph at the Magellan-Clay telescope, which allows us to measure up to 17 chemical species. The chemical composition of these stars reflects the imprint of a variety of type~II supernovae. A combination of low- to intermediate-mass core-collapse and hypernovae ($\\sim10-70 M_{\\odot}$) is required to account for the abundance patterns of the lighter elements up to the Fe-peak. The trend of the heavy elements suggests the involvement of compact binary merger events and fast-rotating (up to $\\sim300$ km s$^{-1}$) intermediate-mass to massive metal-poor stars ($\\sim25-120 M_{\\odot}$) that are the sources of rapid- and slow-processes, respectively. Additionally, asymptotic giant branch stars contribute to a wide dispersion of [Ba/Mg] and [Ba/Eu]. The absence of an $\\alpha-$knee in our data indicates that type Ia supernovae did not contribute in the very metal-poor region ( [Fe/H]$\\leq-2.0$). However, they might have started to pollute the interstellar medium at [Fe/H]$>-2.0$, given the relatively low [Co/Fe] in this metallicity region.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2024-04-30T18:00:01.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "pristine inner galaxy survey",
      "sagittarius dwarf galaxy",
      "largest detailed chemical analysis",
      "metal-poor stars",
      "giant branch stars contribute"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}