{
  "id": "2212.06877",
  "version": "v1",
  "published": "2022-12-13T19:49:06.000Z",
  "updated": "2022-12-13T19:49:06.000Z",
  "title": "The gas and stellar content of a metal-poor galaxy at $z=8.496$ revealed by JWST and ALMA",
  "authors": [
    "K. E. Heintz",
    "C. Giménez-Arteaga",
    "S. Fujimoto",
    "G. Brammer",
    "D. Espada",
    "S. Gillman",
    "J. González-López",
    "T. R. Greve",
    "Y. Harikane",
    "B. Hatsukade",
    "K. K. Knudsen",
    "A. M. Koekemoer",
    "K. Kohno",
    "V. Kokorev",
    "M. M. Lee",
    "G. E. Magdis",
    "E. J. Nelson",
    "F. Rizzo",
    "R. L. Sanders",
    "D. Schaerer",
    "A. E. Shapley",
    "V. B. Strait",
    "F. Sun",
    "S. Toft",
    "F. Valentino",
    "A. P. Vijayan",
    "D. Watson",
    "F. E. Bauer",
    "C. R. Christiansen",
    "S. N. Wilson"
  ],
  "comment": "Submitted to AAS journals",
  "categories": [
    "astro-ph.GA",
    "astro-ph.CO"
  ],
  "abstract": "We present a joint analysis of the galaxy S04590 at $z=8.496$ based on NIRSpec, NIRCam, and NIRISS observations obtained through as part of Early Release Observations programme of the James Webb Space Telescope (JWST) and the far-infrared [CII]-$158\\mu$m emission line detected by dedicated Atacama Large Millimeter/submillimeter Array (ALMA) observations. We determine the physical properties of S04590 from modelling of the spectral energy distribution (SED) and through the redshifted optical nebular emission lines detected with JWST/NIRSpec. The best-fit SED model reveals a low-mass ($M_\\star = 10^{7.2}-10^{8}\\,M_{\\odot}$) galaxy with a low oxygen abundance of $12+\\log{\\rm (O/H)} = 7.16^{+0.10}_{-0.12}$ derived from the strong nebular and auroral emission lines. Assuming that [CII] effectively traces the interstellar medium (ISM), we estimate the total gas mass of the galaxy to be $M_{\\rm gas} = (8.0\\pm 4.0)\\times 10^{8}\\,M_\\odot$ based on the luminosity and spatial extent of [CII]. This yields an exceptionally high gas fraction, $f_{\\rm gas} = M_{\\rm gas}/(M_{\\rm gas} + M_\\star) \\gtrsim 90\\%$, though still consistent within the range expected for its low metallicity. We further derive the metal mass of the galaxy based on the gas mass and gas-phase metallicity, which we find to be consistent with the expected metal production from Type II supernovae. Finally, we make the first constraints on the dust-to-gas (DTG) and dust-to-metals (DTM) ratios of galaxies in the epoch of reionization at $z\\gtrsim 6$, showing overall low mass ratios of logDGT $<-3.8$ and logDTM $<-0.5$, though consistent with local scaling relations and in particular the local metal-poor galaxy I Zwicky 18. Our analysis highlights the synergy between ALMA and JWST in characterizing the gas, metal, and stellar content of the first generation of galaxies.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2022-12-13T19:49:06.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "stellar content",
      "metal-poor galaxy",
      "overall low mass ratios",
      "optical nebular emission lines",
      "dedicated atacama large millimeter/submillimeter array"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}