TY - JOUR
T1 - Dissociative recombination of protonated formic acid: implications for molecular cloud and cometary chemistry
AU - Vigren, E.
AU - Hamberg, M.
AU - Zhaunerchyk, V.
AU - Kaminska, M.
AU - Semaniak, J.
AU - LArsson, M.
AU - Thomas, R.D.
AU - Af Ugglas, M.
AU - Kashperka, I.
AU - Millar, TJ
AU - Walsh, C.
AU - Roberts, H.
AU - Geppert, W.D.
PY - 2010/2
Y1 - 2010/2
N2 - At the heavy ion storage ring CRYRING in Stockholm, Sweden, we have investigated the dissociative recombination
of DCOOD2+ at low relative kinetic energies, from ~1 meV to 1 eV. The thermal rate coefficient has been
found to follow the expression k(T) = 8.43 × 10-7 (T/300)^-0.78 cm3 s-1 for electron temperatures, T, ranging from
~10 to ~1000 K. The branching fractions of the reaction have been studied at ~2 meV relative kinetic energy.
It has been found that ~87% of the reactions involve breaking a bond between heavy atoms. In only 13% of the
reactions do the heavy atoms remain in the same product fragment. This puts limits on the gas-phase production of
formic acid, observed in both molecular clouds and cometary comae. Using the experimental results in chemical
models of the dark cloud, TMC-1, and using the latest release of the UMIST Database for Astrochemistry improves
the agreement with observations for the abundance of formic acid. Our results also strengthen the assumption that
formic acid is a component of cometary ices.
AB - At the heavy ion storage ring CRYRING in Stockholm, Sweden, we have investigated the dissociative recombination
of DCOOD2+ at low relative kinetic energies, from ~1 meV to 1 eV. The thermal rate coefficient has been
found to follow the expression k(T) = 8.43 × 10-7 (T/300)^-0.78 cm3 s-1 for electron temperatures, T, ranging from
~10 to ~1000 K. The branching fractions of the reaction have been studied at ~2 meV relative kinetic energy.
It has been found that ~87% of the reactions involve breaking a bond between heavy atoms. In only 13% of the
reactions do the heavy atoms remain in the same product fragment. This puts limits on the gas-phase production of
formic acid, observed in both molecular clouds and cometary comae. Using the experimental results in chemical
models of the dark cloud, TMC-1, and using the latest release of the UMIST Database for Astrochemistry improves
the agreement with observations for the abundance of formic acid. Our results also strengthen the assumption that
formic acid is a component of cometary ices.
U2 - 10.1088/0004-637X/709/2/1429
DO - 10.1088/0004-637X/709/2/1429
M3 - Article
VL - 709
SP - 1029
EP - 1034
JO - Astrophysical Journal
JF - Astrophysical Journal
ER -