A spectral line survey in the 2 mm and 1.3 mm windows toward the carbon rich envelope of IRC +10216

We present the results of our spectral line surveys in the 2 mm and 1.3 mm windows toward the carbon rich envelope of IRC +10216. Totally 377 lines are detected, among which 360 lines are assigned to 57 known molecules (including 29 rare isotopomers and 2 cyclic isomers). Only 17 weak lines remain unidentified. Rotational lines of isotopomers 13CCH and HN13C are detected for the first time in IRC +10216. The detection of the formaldehyde lines in this star is also confirmed. Possible abundance difference among the three 13C substituted isotopic isomers of HC3N is reported. Isotopic ratios of C and O are confirmed to be non-solar while those of S and Si to be nearly solar. Column densities have been estimated for 15 molecular species. Modified spectroscopic parameters have been calculated for NaCN, Na13CN, KCN and SiC2. Transition frequencies from the present observations were used to improve the spectroscopic parameters of Si13CC, 29SiC2 and 30SiC2.Comment: 17 pages of text, 18 pages of 14 tables, 35 pages of 4 figures, a typo corrected in Abstrac

Perspective from a Younger Generation -- The Astro-Spectroscopy of Gisbert Winnewisser

Gisbert Winnewisser's astronomical career was practically coextensive with the whole development of molecular radio astronomy. Here I would like to pick out a few of his many contributions, which I, personally, find particularly interesting and put them in the context of newer results.Comment: 14 pages. (Co)authored by members of the MPIfR (Sub)millimeter Astronomy Group. To appear in the Proceedings of the 4th Cologne-Bonn-Zermatt-Symposium "The Dense Interstellar Medium in Galaxies" eds. S. Pfalzner, C. Kramer, C. Straubmeier, & A. Heithausen (Springer: Berlin

PRECISION BROADBAND SPECTROSCOPY IN THE TETRAHERTZ REGION

$^{a}$M. Liedtke et al., J. Mol. Sectrosc. 161, 317-321 (1993). $^{b}$G. Winnerwisser et al., J. Mol. Spectrosc. 165, 294-300 (1994).Author Institution: Physikalisches Institut, Universitaet zu Koeln, D-50937 Koeln; Microwave Spectroscopy Laboratory, Applied Physics InstituteFor the first time precision broadband spectroscopic measurements have been performed in the spectral region up to 1.1 THz. Continuous frequencies coverage and microwave accuracy are achieved by employing frequency and phase stabilized Backward Wave Oscillators (BWOs). This breakthrough in high-resolution scanning spectroscopy became possible by the opening of the borders between East and West and essentially by the collaborative efforts between Cologne University, Germany, and the Institute of Applied Physics, Nizhnii Novgorod, $Russia.^{a}$ Extensive measurements have been performed on HSSH, HOOH, their various isotopomers, and astrophysically relevant molecules and radicals. Some of their spectra will be presented. We have performed extensive measurements of the $^{r}Q_{Ka}$ branches for $K_{a}\geq 2$ of HSSH and its various isotopomers for two purposes: (i) to obtain new spectroscopic information concerning the anomalous K-doubling and the mass dependence of the torsional problem and (ii) to demonstrate the hitherto unknown wide tunability of the employed BWO’s and the high sensitivity of the new Cologne terabertz spectrometer. The essential components of the Cologne spectrometer $system^{b}$ consist of the BWO’s supplied by the ISTOK Research and Production Company (Fryazino, Moscow region), a newly designed multiplier-mixer with low noise HEMT amplifier, two millimeter-wave synthesizers (78 to 118 GHz; 118-178 GHz from the Institute of Electronic Measurement, KVARZ Nizhnii Novgorod), and a He-cooled InSb detector