1999/04/13 by Nagayoshi Ohashi, Siow Wang Lee, David J. Wilner +1 · 2 citations
Earth and Planetary Sciences · Physics and Astronomy · #Astrophysics and Star Formation Studies #Atmospheric Ozone and Climate #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/312067
14 pages, 4 figures, AAS-LaTex v4.0, will be published in ApJL
arxiv created 1999/04/13 · openalex publication_date 1999/06/10 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We have carried out observations of the starless core L1544 in the CCS ( J N = 3 2 -2 1 ) line at 9 mm wavelength using the Berkeley-Illinois-Maryland Association array. The maps show an elongated condensation, 0.15 × 0.045 pc in size, with stronger emission at the edges. The appearance is consistent with a flattened, ringlike structure viewed at high inclination to the line of sight. The CCS molecule is likely heavily depleted in the inner part of the core. The position velocity diagram along the major axis shows a remarkable pattern, a "tilted ellipse," that can be reproduced by a simple model ring with motions of both infall and rotation. The models suggest comparable velocities for infall and rotation, ~0.1 km s -1 , in the outermost envelope, at radius 15,000 AU.