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Title: FIRST DETECTION OF [C I] {sup 3}P{sub 1}–{sup 3}P{sub 0} EMISSION FROM A PROTOPLANETARY DISK

We performed single point [C i] {sup 3}P{sub 1}–{sup 3}P{sub 0} and CO J = 4–3 observations toward three T Tauri stars (TTSs), DM Tau, LkCa 15, and TW Hya, using the Atacama Large Millimeter/submillimeter Array Band 8 qualification model receiver installed on the Atacama Submillimeter Telescope Experiment. Two protostars (PSs) in the Taurus L1551 region, L1551 IRS 5 and HL Tau, were also observed. We successfully detected [C i] emission from the protoplanetary disk around DM Tau as well as the protostellar targets. The spectral profile of the [C i] emission from the protoplanetary disk is marginally single-peaked, suggesting that atomic carbon (C) extends toward the outermost disk. The detected [C i] emission is optically thin and the column densities of C are estimated to be ≲10{sup 16} and ∼10{sup 17} cm{sup −2} for the TTS targets and the PSs, respectively. We found a clear difference in the total mass ratio of C to dust, M(C)/M(dust), between the TTSs and protostellar targets; the M(C)/M(dust) ratio of the TTSs is one order of magnitude smaller than that of the PSs. The decrease of the estimated M(C)/M(dust) ratios for the disk sources is consistent with a theoretical prediction that the atomicmore » C can survive only in the near surface layer of the disk and C{sup +}/C/CO transition occurs deeper into the disk midplane.« less
Authors:
;  [1] ;  [2] ;  [3] ;  [4] ;  [5]
  1. College of Science, Ibaraki University, Bunkyo 2-1-1, Mito 310-8512 (Japan)
  2. Nobeyama Radio Observatory, Minamimaki, Minamisaku, Nagano 384-1305 (Japan)
  3. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Yoshinodai 3-1-1, Sagamihara, Kanagawa 229-8510 (Japan)
  4. Laboratoire AIM, CEA/DSM-CNRS-Université Paris, Diderot, IRFU/Service d’Astrophysique, CEA, Saclay, F-91191 Gif-sur-Yvette Cedex (France)
  5. National Astronomical Observatory of Japan, Osawa 2-21-1, Mitaka, Tokyo 181-8588 (Japan)
Publication Date:
OSTI Identifier:
22518817
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 802; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CARBON; CARBON IONS; CARBON MONOXIDE; DENSITY; DETECTION; ION EMISSION; LAYERS; MASS; PROTOPLANETS; PROTOSTARS; T TAURI STARS; TELESCOPES