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Dynamical and chemical properties of the "starless" core L1014

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  • A. Crapsi
  • C. H. DeVries
  • Tracy L. Huard
  • J. E. Lee
  • P. C. Myers
  • N. A. Ridge
  • T. L. Bourke
  • N. J. Evans
  • Jørgensen, Jes Kristian
  • J. Kauffmann
  • C. W. Lee
  • Y. L. Shirley
  • C. H. Young

Spitzer Space Telescope observations of a point-like source, L1014-IRS, close to the dust peak of the low-mass dense core L1014, have raised questions about its starless nature. These show the presence of an object with colors expected for an embedded protostar with the implication that L1014-IRS would be the lowest luminosity isolated protostar known, and an ideal target with which to test star formation theories at the low mass end. In order to study its molecular content and to search for the presence of a molecular outflow, we mapped L1014 in at least one transition of 12CO, N2H +, HCO+, CS, and of their isotopologues 13CO, C18O, C17O, N2D+, and H 13CO+, using the Five College Radio Astronomy Observatory (FCRAO), the IRAM 30 m antenna, and the Caltech Submillimeter Observatory (CSO). The data show physical and chemical properties in L1014 typical of moderately evolved dense cores: i.e. H2 central density of a few 105 molecules cm-3, estimated mass of ∼2 M⊙, CO integrated depletion factor less than 10, N(N2H+) ≃ 6 × 1012 cm-2, N(N2D+)/N(N 2H+) equal to 10%, and relatively broad N 2H+ and N2D+ lines (0.35 km s -1). Infall signatures and significant velocity shifts between optically thick and optically thin tracers are not observed in the line profiles. No classical signatures of molecular outflow are found in the 12CO and 13CO FCRAO observations. In particular, no high velocity wings are found, and no well-defined blue-red lobes of 12CO emission are seen in the channel maps. Sensitive, higher resolution observations will clarify the presence of a molecular outflow on a smaller scale than that probed by our observations.

OriginalsprogEngelsk
TidsskriftAstronomy and Astrophysics
Vol/bind439
Udgave nummer3
Sider (fra-til)1023-1032
Antal sider10
ISSN0004-6361
DOI
StatusUdgivet - 1 sep. 2005

ID: 234015510