Revealing a detailed mass distribution of a high-density core   MC27/L1521F in Taurus with ALMA
  We present the results of ALMA observations of dust continuum emission and molecular rotational lines toward a dense core MC27 (aka L1521F) in Taurus, which is considered to be at a very early stage of star formation. The detailed column density distribution on size scales from a few tens AU to ~10,000 AU scale are revealed by combining the ALMA (12 m array + 7 m array) data with the published/unpublished single-dish data. The high angular resolution observations at 0.87 mm with a synthesized beam size of ~0."74 x 0."32 reveal that a protostellar source, MMS-1, is not spatially resolved and lacks associated gas emission, while a starless high-density core, MMS-2, has substructures both in dust and molecular emission. The averaged radial column density distribution of the inner part of MC27/L1521F (r $\lesssim$ 3000 AU) is N(H2) ~r$^{-0.4}$, clearly flatter than that of the outer part, ~r$^{-1.0}$. The complex velocity/spatial structure obtained with previous ALMA observations is located inside the inner flatter region, which may reflect the dynamical status of the dense core. 
Kazuki Tokuda, Toshikazu Onishi, Tomoaki Matsumoto, Kazuya Saigo,   Akiko Kawamura, Yasuo Fukui, Shu-ichiro Inutsuka, Masahi...
astro-ph.GA astro-ph.SR