{
  "id": "2405.11321",
  "version": "v1",
  "published": "2024-05-18T15:31:22.000Z",
  "updated": "2024-05-18T15:31:22.000Z",
  "title": "HCN as a probe of the inner disk in a candidate proto-brown dwarf",
  "authors": [
    "B. Riaz",
    "W. -F. Thi",
    "M. N. Machida"
  ],
  "comment": "Accepted in MNRAS Letters",
  "categories": [
    "astro-ph.SR",
    "astro-ph.GA"
  ],
  "abstract": "The detection of Keplerian rotation is rare among Class 0 protostellar systems. We have investigated the high-density tracer HCN as a probe of the inner disk in a Class 0 proto-brown dwarf candidate. Our ALMA high angular resolution observations show the peak in the HCN (3-2) line emission arises from a compact component near the proto-brown dwarf with a small bar-like structure and a deconvolved size of $\\sim$50 au. Radiative transfer modelling indicates that this HCN feature is tracing the innermost, dense regions in the proto-brown dwarf where a small Keplerian disk is expected to be present. The limited velocity resolution of the observations, however, makes it difficult to confirm the rotational kinematics of this feature. A brightening in the HCN emission towards the core center suggests that HCN can survive in the gas phase in the inner, dense regions of the proto-brown dwarf. In contrast, modelling of the HCO$^{+}$ (3-2) line emission indicates that it originates from the outer pseudo-disk/envelope region and is centrally depleted. HCN line emission can reveal the small-scale structures and can be an efficient observational tool to study the inner disk properties in such faint compact objects where spatially resolving the disk is nearly impossible.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2024-05-18T15:31:22.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "inner disk",
      "candidate proto-brown dwarf",
      "line emission",
      "alma high angular resolution observations",
      "dense regions"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}