{
  "id": "2110.10440",
  "version": "v1",
  "published": "2021-10-20T09:10:35.000Z",
  "updated": "2021-10-20T09:10:35.000Z",
  "title": "SN 2018hfm : A Low-Energy Type II Supernova with Prominent Signatures of Circumstellar Interaction and Dust Formation",
  "authors": [
    "Xinghan Zhang",
    "Xiaofeng Wang",
    "Hanna Sai",
    "Maria Niculescu-Duvaz",
    "Alexei V. Filippenko",
    "WeiKang Zheng",
    "T. G. Brink",
    "Han Lin",
    "Jicheng Zhang",
    "Yongzhi Cai",
    "Jun Mo",
    "Jujia Zhang",
    "E. Baron",
    "J. M. DerKacy",
    "F. Huang",
    "T. -M. Zhang"
  ],
  "doi": "10.1093/mnras/stab3007",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "We present multiband optical photometric and spectroscopic observations of an unusual Type II supernova, SN 2018hfm, which exploded in the nearby (d = 34.67 Mpc) dwarf galaxy PGC 1297331 with a very low star-formation rate (0.0270 M yr-1) and a subsolar metallicity environment(~ 0.5 Z). The V-band light curve of SN 2018hfm reaches a peak with value of -18.69+/-0.64 mag, followed by a fast decline(4.42+/-0.13 mag (100d)-1). After about 50 days, it is found to experience a large flux drop (~3.0 mag in V), and then enters into an unusually faint tail, which indicates a relatively small amount of 56Ni synthesized during the explosion. From the bolometric light curve, SN 2018hfm is estimated to have low ejecta mass (~1.3M) and low explosion energy(~10 50 erg) compared with typical SNe II. The photospheric spectra of SN 2018hfm are similar to those of other SNe II, with P Cygni profiles of the Balmer series and metal lines, while at late phases the spectra are characterised by box-like profiles of HU emission, suggesting significant interaction between the SN ejecta and circumstellar matter. These box-like emission features are found to show increasing asymmetry with time, with the red-side component becoming gradually weaker, indicating that dust is continuously formed in the ejecta. Based on the dust-estimation tool damocles, we find that the dust increases from ~10 -6M to 10 -4 - 10 -3 M between +66.7 d and +389.4 d after explosion.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2021-10-20T09:10:35.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "circumstellar interaction",
      "prominent signatures",
      "low-energy type",
      "dust formation",
      "v-band light curve"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}