{
  "id": "1808.00279",
  "version": "v1",
  "published": "2018-08-01T11:44:15.000Z",
  "updated": "2018-08-01T11:44:15.000Z",
  "title": "The curious case of II Lup: a complex morphology revealed with SAM/NACO and ALMA",
  "authors": [
    "Foteini Lykou",
    "Albert A. Zijlstra",
    "Jacques Kluska",
    "Eric Lagadec",
    "Peter G. Tuthill",
    "Adam Avison",
    "Barnaby R. M. Norris",
    "Quentin A. Parker"
  ],
  "comment": "17 pages, 14 figures, accepted by MNRAS",
  "doi": "10.1093/mnras/sty1903",
  "categories": [
    "astro-ph.SR"
  ],
  "abstract": "We present the first-ever images of the circumstellar environment of the carbon-rich AGB star II Lup in the infrared and sub-mm wavelengths, and the discovery of the envelope's non-spherical morphology with the use of high-angular resolution imaging techniques with the sparse aperture masking mode on NACO/VLT (that enables diffraction limited resolution from a single telescope) and with ALMA. We have successfully recovered images in $Ks$ (2.18$\\mu$m), $L'$ (3.80$\\mu$m) and $M'$ (4.78$\\mu$m), that revealed the non-spherical morphology of the circumstellar envelope around II Lup. The stellar surface of the AGB star is unresolved (i.e. $\\leq30$ mas in $Ks$) however the detected structure extends up to 110 mas from the star in all filters. Clumps have been found in the $Ks$ maps, while at lower emission levels a hook-like structure appears to extend counter-clockwise from the south. At larger spatial scales, the circumstellar envelope extends up to approximately 23 arcsec, while its shape suggests a spiral at four different molecules, namely CO, SiO, CS and HC$_3$N, with an average arm spacing of 1.7 arcsec which would imply an orbital period of 128 years for a distance of 590pc.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2018-08-01T11:44:15.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "complex morphology",
      "curious case",
      "circumstellar envelope extends",
      "non-spherical morphology",
      "larger spatial scales"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 17,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}