Letter to the Editor
The rotational spectrum of protonated sulfur dioxide, HOSO+
Harvard-Smithsonian Center for Astrophysics, 60 Garden St.,
2 School of Engineering & Applied Sciences, Harvard University, 29 Oxford St., Cambridge, MA 02138, USA
3 I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany
Received: 21 July 2011
Accepted: 19 August 2011
Aims. We report on the millimeter-wave rotational spectrum of protonated sulfur dioxide, HOSO+.
Methods. Ten rotational transitions between 186 and 347 GHz have been measured to high accuracy in a negative glow discharge.
Results. The present measurements improve the accuracy of the previously reported centimeter-wave spectrum by two orders of magnitude, allowing a frequency calculation of the principal transitions to about 4 km s-1 in equivalent radial velocity near 650 GHz, or one linewidth in hot cores and corinos.
Conclusions. Owing to the high abundance of sulfur-bearing molecules in many galactic molecular sources, the HOSO+ ion is an excellent candidate for detection, especially in hot cores and corinos in which SO2 and several positive ions are prominent.
Key words: ISM: molecules / radio lines: ISM / molecular processes / molecular data / line: identification
© ESO, 2011