OSU Navigation Bar

The Ohio State University University Libraries Knowledge Bank

LABORATORY AND TENTATIVE ASTRONOMICAL DETECTION OF THIOCYANIC ACID, HSCN

Please use this identifier to cite or link to this item: http://hdl.handle.net/1811/33379

Show simple item record

Files Size Format View
abstract.gif 30.00Kb GIF image Thumbnail of LABORATORY AND TENTATIVE ASTRONOMICAL DETECTION OF THIOCYANIC ACID, HSCN

dc.creator Brunken, Sandra en_US
dc.creator Yu, Zhenhong en_US
dc.creator McCarthy, Michael C. en_US
dc.creator Gottlieb, Carl A. en_US
dc.creator Thaddeus, Patrick en_US
dc.creator Belloche, Arnaud en_US
dc.creator Menten, Karl M. en_US
dc.date.accessioned 2008-07-15T13:39:55Z
dc.date.available 2008-07-15T13:39:55Z
dc.date.issued 2008 en_US
dc.identifier 2008-FD-03 en_US
dc.identifier.uri http://hdl.handle.net/1811/33379
dc.description Author Institution: Harvard Smithsonian Center for Astrophysics and School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138; Max-Planck-Institut fur Radioastronomie, 53121 Bonn, Germany en_US
dc.description.abstract We present the first measurements of the rotational spectrum of thiocyanic acid (HSCN) in the microwave and mm-wave regions. HSCN is an isomer of the spectroscopically and astronomically well-studied molecule isothiocyanic acid (HNCS). HSCN has been calculated to lie only 4-14~kcal/mol higher in energy than the most stable isomer HNCS, yet to date HSCN had only been characterised experimentally by matrix-IR spectroscopy. We now succeeded to produce HSCN in a discharge of H$_2$S and either (CN)$_2$ or CH$_3$CN in sufficient amounts for its spectroscopic investigation in the gas phase. Three {\it a}-type rotational transitions in the $K_a=0$ ladder and four in the $K_a=1$ ladder were measured in the frequency range $10-35$~GHz with our Fourier Transform Microwave Spectrometer (FTM) in a molecular beam. The identification was confirmed by the observation of 6 singly and doubly substituted isotopic species at predicted isotopic shifts. Furthermore, we were able to resolve and analyse the distinctive hyperfine structure due to $^{14}$N and D in all species containing these nuclei, providing additional evidence for the identification. An experimental structure derived from the isotopic measurements will be presented. For the main isotopic species additional $\Delta K_a=0$ transitions were observed in selected frequency regions up to 350~GHz with a free-space millimeter-wave absorption spectrometer. Lines of HSCN were surprisingly strong through a dc discharge of H$_2$S and (CN)$_2$, allowing to observe spectra up to $J=30$ and $K_a=7$, as shown in the figure. \\ We also report a tentative detection of HSCN towards SgrB2(M) via four $K_a=0$ $a$-type transitions observed in the 3-mm band with the IRAM 30m telescope. The observations yield an abundance of HSCN only a factor 2-5 lower than that of the lowest energy isomer HNCS. en_US
dc.language.iso English en_US
dc.title LABORATORY AND TENTATIVE ASTRONOMICAL DETECTION OF THIOCYANIC ACID, HSCN en_US
dc.type Article en_US