Volume 449, Number 2, April II 2006
|Page(s)||631 - 639|
|Section||Interstellar and circumstellar matter|
|Published online||21 March 2006|
Modeling the ortho-to-para abundance ratio of cyclic C3H2 in cold dense cores
Chemical Physics Program, The Ohio State University, Columbus, OH 43210, USA e-mail: email@example.com
2 Department of Physics, The Ohio State University, Columbus, OH 43210, USA e-mail: firstname.lastname@example.org
3 Departments of Physics, Chemistry and Astronomy, The Ohio State University, Columbus, OH 43210, USA e-mail: email@example.com
Accepted: 7 December 2005
Aims.We report a detailed attempt to model the ortho-to-para abundance ratio of c-C3H2 so as to reproduce observed values in the cores of the well-known source TMC-1. According to observations, the ortho-to-para ratios vary, within large uncertainties, from a low of near unity to a high of approximately three depending on the core. Methods.We used the osu.2003 network of gas-phase chemical reactions augmented by reactions that specifically consider the formation, depletion, and interconversion of the ortho and para forms of c-C3H2 and its precursor ion c-C3H. We investigated the sensitivity of the calculated ortho-to-para ratio for c-C3H2 to a large number of factors. Results.For the less evolved cores C, CP, and D, we had no difficulty reproducing the observed ortho-to-para ratios of 1–2. In order to reproduce observed ortho-to-para ratios of near three, observed for the evolved cores A and B, it was necessary to include rapid ion-catalyzed interconversion processes.
© ESO, 2006
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.