2006/09/20 by B. C. Matthews, Brenda C. Matthews, M. R. Hogerheijde +4 · 1 citation
Chemistry · Physics and Astronomy · #Astrophysics #Astrophysics and Star Formation Studies #Bipolar outflow #Geometry #Jet (fluid) #Molecular Spectroscopy and Structure #Molecular cloud #Outflow #Physics #Protostar #RADIUS #Star formation #Stars #Stellar, planetary, and galactic studies #Torus #Young stellar object #astro-ph
paper · pdf · doi:10.1086/508645
published as Astrophys.J.652:1366-1373,2006; Astrophys.J.652:1374-1389,2006 · 17 pages, 17 figures (9 colour). Accepted to The Astrophysical Journal. For higher resolution images, see http://astrowww.phys.uvic.ca/~brenda/preprints.html
arxiv created 2006/09/20 · openalex publication_date 2006/11/27 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We investigate the structure of the core surrounding the recently identified deeply embedded young stellar object Barnard 1c. B1c lies within the Perseus molecular cloud at a distance of 250 pc. It is a deeply embedded core of 2.4 M ☉ (Kirk et al.) and a luminosity of 4 ± 2 L ☉ . Observations (and resolutions) of 12 CO J = 1-0 (9 2 × 5 9), 13 CO J = 1-0, C 18 O J = 1-0 (14 3 × 6 7), HCO + J = 1-0 (7 6 × 5 8), and N 2 H + J = 1-0 (5 9 × 4 6) were obtained with the BIMA array, together with the continuum at 3.3 mm (6 4 × 4 9) and 2.7 mm (9 5 × 6 3). Single-dish measurements of N 2 H + J = 1-0 and HCO + J = 1-0 with FCRAO reveal the larger scale emission in these lines with ~60 resolution. The 12 CO and HCO + emission traces the outflow extending over the full field of view (2 1), which coincides in detail with the S-shaped jet recently found in Spitzer IRAC imaging. The N 2 H + emission, which anticorrelates spatially with the C 18 O emission, originates from a rotating envelope with effective radius ~2400 AU and mass 2.1-2.9 M ☉ , as derived from the 3.3 mm continuum emission. N 2 H + emission is absent from a 600 AU diameter region around the young star, offset from the continuum peak. The remaining N 2 H + emission may lie in a coherent torus of dense material. With its outflow and rotating envelope, B1c closely resembles the previously studied object L483 mm, and we conclude that it is a protostar in an early stage of evolution, i.e., Class 0 or in transition between Class 0 and Class I. We hypothesize that heating by the outflow and star has desorbed CO from grains, which has destroyed N 2 H + in the inner region, and surmise that the presence of grains without ice mantles in this warm inner region can explain the unusual polarization signature observed from B1c.