Cordiner, MA, Charnley, SB, Buckle, JV et al. (2 more authors) (2011) Discovery of Interstellar Anions in Cepheus and Auriga. The Astrophysical Journal Letters, 730 (2). L18. ISSN 2041-8205
Abstract
We report the detection of microwave emission lines from the hydrocarbon anion C6H– and its parent neutral C6H in the star-forming region L1251A (in Cepheus), and the pre-stellar core L1512 (in Auriga). The carbon-chain-bearing species C4H, HC3N, HC5N, HC7N, and C3S are also detected in large abundances. The observations of L1251A constitute the first detections of anions and long-chain polyynes and cyanopolyynes (with more than five carbon atoms) in the Cepheus Flare star-forming region, and the first detection of anions in the vicinity of a protostar outside of the Taurus molecular cloud complex, indicating a possible wider importance for anions in the chemistry of star formation. Rotational excitation temperatures have been derived from the HC3N hyperfine structure lines and are found to be 6.2 K for L1251A and 8.7 K for L1512. The anion-to-neutral ratios are 3.6% and 4.1%, respectively, which are within the range of values previously observed in the interstellar medium, and suggest a relative uniformity in the processes governing anion abundances in different dense interstellar clouds. This research contributes toward the growing body of evidence that carbon chain anions are relatively abundant in interstellar clouds throughout the Galaxy, but especially in the regions of relatively high density and high depletion surrounding pre-stellar cores and young, embedded protostars.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2011. The American Astronomical Society. Reproduced in accordance with the publisher's self-archiving policy. |
Keywords: | Astrochemistry; ISM: abundances; ISM: clouds; ISM: molecules; Stars: formation |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Physics and Astronomy (Leeds) > Astrophysics (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 22 May 2019 10:12 |
Last Modified: | 22 May 2019 10:12 |
Status: | Published |
Publisher: | American Astronomical Society |
Identification Number: | 10.1088/2041-8205/730/2/L18 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:107147 |