Open AccessRapid neutral–neutral reactions at low temperatures: a new network and first results for TMC‐1
Author(s) -
Smith Ian W. M.,
Herbst Eric,
Chang Qiang
Publication year - 2004
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2004.07656.x
Subject(s) - physics , interstellar cloud , energetic neutral atom , molecular cloud , astrophysics , table (database) , reaction rate , astrochemistry , chemical physics , interstellar medium , thermodynamics , chemistry , nuclear physics , organic chemistry , galaxy , computer science , stars , plasma , data mining , catalysis
There is now ample evidence from an assortment of experiments, especially those involving the CRESU (Cinétique de Réaction en Ecoulement Supersonique Uniforme) technique, that a variety of neutral–neutral reactions possess no activation energy barrier and are quite rapid at very low temperatures. These reactions include both radical–radical systems and, more surprisingly, systems involving an atom or a radical and one ‘stable’ species. Generalizing from the small but growing number of systems studied in the laboratory, we estimate reaction rate coefficients for a larger number of such reactions and include these estimates in a new network of gas‐phase reactions for use in low‐temperature interstellar chemistry. Designated osu.2003, the new network is available on the World Wide Web and will be continually updated. A table of new results for molecular abundances in the dark cloud TMC‐1 (CP) is provided and compared with results from an older (new standard model; nsm) network.