Bibcode
García-Hernández, D. A.; Masseron, T.; Zamora, O.; Manchado, A.; Rao, N. K.; Reddy, A. B. S.; Lambert, D. L.; Yurchenko, S.; Tennyson, J.
Bibliographical reference
Radiative Signatures from the Cosmos, ASP Conference Series, Vol. 519, Proceedings of a conference held 23-26 October, 2018 at Sorbonne University, Paris, France. Edited by K. Werner, C. Stehle, T. Rauch, and T. Lanz. San Francisco: Astronomical Society of the Pacific, 2019, p.147
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7
2019
Citations
0
Refereed citations
0
Description
Diatomic carbon (C2) is ubiquitous in astronomical
environments, from comets and stars to translucent clouds and the
interstellar medium. In particular, the C2 bands (mainly the
Ballik-Ramsay and Phillips transitions) are an important source of
opacity in the near-IR region of carbon stars such as the hydrogen
deficient carbon-rich (HdC) or R Coronae Borealis (RCB) stars. Present
C2 linelists are still not accurate enough (e.g., in
wavelength positions) to model the near-IR spectra of HdC and RCB stars,
strongly limiting our ability to properly model their complex spectra
and to extract the elemental (an isotopic, when possible) abundances of
key elements like C, N, O, F, etc. Very recently, a new near-IR
C2 linelist (including both Ballik-Ramsay and Phillips
systems, among others) have been generated by the ExoMol project
(Yurchenko et al. 2018; see www.exomol.com). The synthetic
spectrum constructed for the benchmark HdC star HD 137613, using this
new C2 linelist, provides an unprecedented match to its
high-resolution (R˜50,000) observed spectrum. The new
C2 linelist is thus expected to significantly improve the
near-IR chemical analysis for HdC and RCB stars but also for normal
carbon stars (e.g., C-rich AGB and dwarf stars) and even Solar System
bodies like comets.