N2H+ and C18O Depletion in a Cold Dark Cloud

  title={N2H+ and C18O Depletion in a Cold Dark Cloud},
  author={Edwin A. Bergin and Jo{\~a}o Alves and Tracy L. Huard and Charles J. Lada},
  journal={The Astrophysical Journal},
We present sensitive, high angular resolution molecular line observations of C18O and N2H+ toward the dark globule B68. We directly compare these data with the near-infrared extinction measurements of Alves, Lada, & Lada to derive the first evidence for the depletion of N2H+, and by inference N2, in a prestellar dark cloud. We also find widespread C18O depletion throughout the centrally condensed core of the B68 cloud. Specifically, we find the N2H+ emission to peak in a shell partially… Expand
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