{
  "id": "2410.23392",
  "version": "v1",
  "published": "2024-10-30T18:52:12.000Z",
  "updated": "2024-10-30T18:52:12.000Z",
  "title": "The SOFIA Massive (SOMA) Star Formation Q-band Follow-up. I. -Carbon-Chain Chemistry of Intermediate-Mass Protostars-",
  "authors": [
    "Kotomi Taniguchi",
    "Prasanta Gorai",
    "Jonathan C. Tan",
    "Miguel Gomez-Garrido",
    "Ruben Fedriani",
    "Yao-Lun Yang",
    "T. K. Sridharan",
    "Kei Tanaka",
    "Masao Saito",
    "Yichen Zhang",
    "Lawrence Morgan",
    "Giuliana Cosentino",
    "Chi-Yan Law"
  ],
  "comment": "Accepted for publication in the Astronomy and Astrophysics (A&A)",
  "categories": [
    "astro-ph.GA",
    "astro-ph.SR"
  ],
  "abstract": "Evidence for similar chemical characteristics around low- and high-mass protostars has been found: in particular, a variety of carbon-chain species and complex organic molecules (COMs) are formed around them. On the other hand, the chemical compositions around intermediate-mass (IM; $2 M_{\\odot} < m_* <8 M_{\\odot}$) protostars have not been studied with large samples. In particular, it is unclear the extent to which carbon-chain species are formed around them. We aim to obtain the chemical compositions, particularly focusing on carbon-chain species, towards a sample of IM protostars. We have conducted Q-band (31.5-50 GHz) line survey observations towards eleven mainly intermediate-mass protostars with the Yebes 40 m radio telescope. The target protostars were selected from a sub-sample of the source list of the SOFIA Massive (SOMA) Star Formation project. Nine carbon-chain species (HC$_3$N, HC$_5$N, C$_3$H, C$_4$H, $linear-$H$_2$CCC, $cyclic-$C$_3$H$_2$, CCS, C$_3$S, and CH$_3$CCH), three COMs (CH$_3$OH, CH$_3$CHO, and CH$_3$CN), H$_2$CCO, HNCO, and four simple sulfur (S)-bearing species ($^{13}$CS, C$^{34}$S, HCS$^+$, H$_2$CS) have been detected. The rotational temperatures of HC$_5$N are derived to be $\\sim20-30$ K in three IM protostars and they are very similar compared to those around low- and high-mass protostars. These results indicate that carbon-chain molecules are formed in lukewarm ($\\sim20-30$ K) gas around the IM protostars by the Warm Carbon-Chain Chemistry (WCCC) process. Carbon-chain formation occurs ubiquitously in the warm gas around protostars across a wide range of stellar masses. Carbon-chain molecules and COMs coexist around most of the target IM protostars, which is similar to the situation in low- and high-mass protostars. The chemical characteristics around protostars are common in the low-, intermediate- and high-mass regimes.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2024-10-30T18:52:12.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "star formation q-band follow-up",
      "carbon-chain chemistry",
      "im protostars",
      "carbon-chain species",
      "sofia massive"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}