{
  "id": "2305.07066",
  "version": "v1",
  "published": "2023-05-11T18:03:03.000Z",
  "updated": "2023-05-11T18:03:03.000Z",
  "title": "Mini-Quenching of High-Redshift Galaxies by Bursty Star Formation",
  "authors": [
    "Tibor Dome",
    "Sandro Tacchella",
    "Anastasia Fialkov",
    "Avishai Dekel",
    "Omri Ginzburg",
    "Sharon Lapiner",
    "Tobias J. Looser"
  ],
  "comment": "Submitted to MNRAS, 10 pages, 3 figures, 2 tables, comments welcome",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "The recent observation of a low-mass $z=5.2$ and an intermediate-mass $z=7.3$ (JADES-GS-z7-01-QU) quenched galaxy with JWST / NIRSpec is the first evidence of halted star formation above $z\\sim 5$. Here we show how bursty star formation at high redshift gives rise to temporarily quenched, or miniquenched galaxies in the mass range $M_{\\star} = 10^7-10^9 \\ M_{\\odot}$ using three models of galaxy formation: the periodic box simulation IllustrisTNG, the zoom-in simulation VELA and an empirical halo model. The main causes for mini-quenching are stellar feedback, lack of gas accretion onto galaxies and galaxy-galaxy interactions. The abundance of mini-quenching events agrees across the three models: the population first appears below $z\\sim 8$, after which the fraction of miniquenched galaxies increases with cosmic time, from $\\sim 0.5$% at $z=7$ to $\\sim 1-2$% at $z=4$, corresponding to comoving number densities of $8.0\\times 10^{-6}$ Mpc$^{-3}$ and $5.4\\times 10^{-4}$ Mpc$^{-3}$, respectively. The star formation rate duty cycle ($f_{\\mathrm{duty}}\\sim 99.56^{+0.4}_{-4.5}$% at $z=7$) inferred for VELA galaxies is consistent therewith. Star formation histories (SFHs) in VELA suggest that mini-quenching at $z=4-8$ is short-lived with a duration of $\\sim 20-40$ Myr, which is close to the free-fall timescale of the inner halo. However, mock spectral energy distributions of miniquenched galaxies in IllustrisTNG and VELA do not match JADES-GS-z7-01-QU photometry, unless their SFHs are artificially altered to be more bursty on timescales of $\\sim 40$ Myr. Studying miniquenched galaxies might aid in calibrating the sub-grid models governing galaxy formation, as these may not generate sufficient burstiness at high redshift to explain the SFH inferred for JADES-GS-z7-01-QU.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2023-05-11T18:03:03.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "bursty star formation",
      "high-redshift galaxies",
      "miniquenched galaxies",
      "mini-quenching",
      "star formation rate duty cycle"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 10,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}