Formation of CN^{-}, C_{3}N^{-}, and C_{5}N^{-} Molecules by Radiative Electron Attachment and their Destruction by Photodetachment.
The existence of negative ions in interstellar clouds has been associated for several decades with the process of radiative electron attachment. In this Letter, we report compelling evidence supporting the fact that the radiative attachment of a low-energy electron is inefficient to form the carbon chain anions CN^{-}, C_{3}N^{-}, and C_{5}N^{-} detected in interstellar clouds. The validity of the approach is confirmed by good agreement with experimental data obtained for the inverse photodetachment process, which represents the major cause of anion destruction in interstellar space. As a consequence, we suggest alternative models that could explain the formation of anions.
Department of Physics, University of Central Florida, Orlando, Florida 32816, USA.
Marjan
M
Khamesian
Department of Physics and Astronomy, Drake University, Des Moines, Iowa 50311, USA.
Nicolas
N
Douguet
Department of Physics and Astronomy, Drake University, Des Moines, Iowa 50311, USA.
Samantha
S
Fonseca Dos Santos
Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay, bâtiment 505, Campus d'Orsay, 91405 Orsay cedex, France.
Olivier
O
Dulieu
Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay, bâtiment 505, Campus d'Orsay, 91405 Orsay cedex, France.
Maurice
M
Raoult
Department of Physics & Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom.
Will J
WJ
Brigg
Department of Physics, University of Central Florida, Orlando, Florida 32816, USA.
Viatcheslav
V
Kokoouline