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arXiv · 1102.0205

Energetic processes revealed by spectrally resolved high-J CO lines in low-mass star-forming regions with Herschel-HIFI

Umut A. Yildiz·Ewine F. van Dishoeck·Lars E. Kristensen·Ruud Visser·Greg Herczeg·Tim A. van Kempen·Jes K. Jorgensen·Michiel R. Hogerheijde
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Abstract

Herschel-HIFI observations of high-J lines (up to J_u=10) of 12CO, 13CO and C18O are presented toward three deeply embedded low-mass protostars in NGC1333. The observations show several energetic components including shocked and quiescent gas. Radiative transfer models are used to quantify the C18O envelope abundance which require a jump in the abundance at an evaporation temperature, T_ev ~25 K, providing new direct evidence of a CO ice evaporation zone around protostars. The abundance in the outermost part of the envelope, X_0, is within the canonical value of 2x10^-4; however the inner abundance, X_in, is found around a factor of 3-5 lower than X_0.

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Umut A. Yildiz, Ewine F. van Dishoeck, Lars E. Kristensen, Ruud Visser, Greg Herczeg, Tim A. van Kempen, Jes K. Jorgensen, Michiel R. Hogerheijde. 2011-02-02. Energetic processes revealed by spectrally resolved high-J CO lines in low-mass star-forming regions with Herschel-HIFI. https://doi.org/10.1051/eas%2F1152063

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