2014A&A...569L...5M -
Astronomy and Astrophysics, volume 569, L5-5 (2014/9-1)
Revised spectroscopic parameters of SH+ from ALMA and IRAM 30m observations.
MUELLER H.S.P., GOICOECHEA J.R., CERNICHARO J., AGUNDEZ M., PETY J., CUADRADO S., GERIN M., DUMAS G. and CHAPILLON E.
Abstract (from CDS):
Hydrides represent the first steps of interstellar chemistry. Sulfanylium (SH+), in particular, is a key tracer of energetic processes. We used ALMA and the IRAM 30m telescope to search for the lowest frequency rotational lines of SH+ toward the Orion Bar, the prototypical photo-dissociation region illuminated by a strong UV radiation field. On the basis of previous Herschel/HIFI observations of SH+, we expected to detect emission of the two SH+ hyperfine structure (HFS) components of the NJ=10-01 fine structure (FS) component near 346GHz. While we did not observe any lines at the frequencies predicted from laboratory data, we detected two emission lines, each ∼15MHz above the SH+ predictions and with relative intensities and HFS splitting expected for SH+. The rest frequencies of the two newly detected lines are more compatible with the remainder of the SH+ laboratory data than the single line measured in the laboratory near 346GHz and previously attributed to SH+. Therefore, we assign these new features to the two SH+ HFS components of the NJ=10-01 FS component and re-determine its spectroscopic parameters, which will be useful for future observations of SH+, in particular if its lowest frequency FS components are studied. Our observations demonstrate the suitability of these lines for SH+ searches at frequencies easily accessible from the ground.
Abstract Copyright:
∼
Journal keyword(s):
molecular data - line: identification - ISM: molecules - radio lines: ISM - ISM: individual objects: Orion Bar
Simbad objects:
6
Full paper
View the references in ADS
To bookmark this query, right click on this link: simbad:2014A&A...569L...5M and select 'bookmark this link' or equivalent in the popup menu