{
  "id": "2403.03697",
  "version": "v1",
  "published": "2024-03-06T13:27:00.000Z",
  "updated": "2024-03-06T13:27:00.000Z",
  "title": "The double-peaked type I X-ray bursts with different mass accretion rate and fuel composition",
  "authors": [
    "Liyu Song",
    "Helei Liu",
    "Chunhua Zhu",
    "Guoqing Zhen",
    "Guoliang Lv",
    "Renxin Xu"
  ],
  "comment": "10 pages, 13 figures, 5 tables, accepted for publication in MNRAS",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "Using the MESA code, we have carried out a detailed survey of the available parameter space for the double-peaked type I X-ray bursts. We find that the double-peaked structure appears at mass accretion rate $\\dot{M}$ in the range of $\\sim(4-8)\\times10^{-10}\\,M_{\\odot}/{\\rm yr}$ when metallicity $Z=0.01$, while in the range of $\\sim(4-8)\\times10^{-9}\\,M_{\\odot}/\\rm{yr}$ when $Z=0.05$. Calculations of the metallicity impact suggest that the double peaks will disappear when $Z\\lesssim0.005$ for $\\dot{M}=5\\times10^{-10}\\,M_{\\odot}/\\rm{yr}$ and $Z\\lesssim0.04$ for $\\dot{M}=5\\times10^{-9}\\,M_{\\odot}/\\rm{yr}$. Besides, the impacts of base heating $Q_{\\rm b}$, as well as nuclear reaction waiting points: $^{22}\\rm{Mg}$, $^{26}\\rm{Si}$, $^{30}\\rm{S}$, $^{34}\\rm{Ar}$, $^{56}{\\rm Ni}$, $^{60}\\rm Zn$, $^{64}\\rm{Ge}$, $^{68}\\rm{Se}$, $^{72}\\rm{Kr}$ have been explored. The luminosity of the two peaks decreases as $Q_{\\rm b}$ increases. $^{68}{\\rm Se}(p,\\gamma){^{69}{\\rm Br}}$ is the most sensitive reaction, the double peaks disappear assuming that $^{56}{\\rm Ni}(p,\\gamma)^{57}{\\rm Cu}$ and $^{64}{\\rm Ge}(p,\\gamma)^{65}{\\rm As}$ reaction rates have been underestimated by a factor of 100 and the $^{22}{\\rm Mg}(\\alpha,p)^{25}{\\rm Al}$ reaction rate has been overestimated by a factor of 100, which indicates that $^{22}{\\rm Mg}$, $^{56}{\\rm Ni}$, $^{64}{\\rm Ge}$, $^{68}{\\rm Se}$ are possibly the most important nuclear waiting points impedance. Comparisons to the double-peaked bursts from 4U 1636-53 and 4U 1730-22 suggest that the nuclear origins of double-peaked type I X-ray bursts are difficult to explain the observed larger peak times ($t_{\\rm p,1}\\gtrsim4\\,{\\rm s}$, $t_{\\rm p,2}\\gtrsim8\\,{\\rm s}$) and smaller peak ratio($r_{1,2}\\lesssim0.5$). The composition of ashes from double-peaked bursts is very different from the single-peaked bursts especially for the heavier p-nuclei.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2024-03-06T13:27:00.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "mass accretion rate",
      "x-ray bursts",
      "double-peaked type",
      "fuel composition",
      "reaction rate"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 10,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}