Letter to the Editor
Rotational transitions of CH2D+ determined by high-resolution IR spectroscopy
I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany e-mail: firstname.lastname@example.org
Accepted: 10 May 2010
Context. Deuterated forms of CH are responsible for deuterium fractionation in warmer environments. Current searches for CH2D+ are hampered by a lack of accurate laboratory data.
Aims. We demonstrate that IR spectroscopy at very high resolution can make accurate rotational predictions.
Methods. By combining a low-temperature ion trap with a narrow-bandwidth IR light source, we are able to measure vibrational transitions with high accuracy. A subsequent fit using an asymmetric rotor model allows predictions of MHz accuracy or even better.
Results. We predict rotational transitions up to 1.5 THz.
Key words: methods: laboratory / ISM: molecules / submillimeter: ISM
© ESO, 2010