90 research outputs found
PURE ROTATIONAL SPECTRUM OF CN+
The pure rotational spectrum of the elusive CN cation has been observed for the first
time using the cryogenic ion trap apparatus Coltrap by applying an action spectroscopy scheme.
For the CN species, the three lowest rotational transitions have been observed
each of which exhibits hyperfine structure from the presence of the N nucleus.
The rare CN isotopolog has been studied up to the
transition.
The observations conclusively confirm CN to occupy a electronic ground state.
Given the ubiquity of the CN radical in space, CN is an appealing candidate for future radio astronomical searches
FELIX SPECTROSCOPY OF LIKELY ASTRONOMICAL MOLECULAR IONS: HC3O+, C2H3CNH+, and C2H5CNH+
Infrared signatures of three molecular ions of relevance to the interstellar medium and planetary atmospheres_x000d_
have been detected at the Free Electron Laser for Infrared eXperiments, FELIX, at Radboud University (Nijmegen, The Netherlands) _x000d_
in combination with the 4K FELion 22-pole ion trap facility. Mid-infrared vibrational modes of protonated tricarbon monoxide, HCO, _x000d_
protonated vinyl cyanide, CHCNH, _x000d_
and protonated ethyl cyanide, CHCNH, were detected using resonant photodissociation of the respective Ne-complexes by monitoring _x000d_
the depletion of their cluster mass signal as a function of wavenumber. The infrared fingerprints compare very favorably_x000d_
with results from high-level quantum-chemical calculations performed at the CCSD(T) level of theory
THE SOLEIL VIEW ON SULFUR RICH OXIDES: THE _3 MODE OF S2O REVISITED
In the course of our recent study of the bending mode of SO (Martin-Drumel el al.; see Talk P1190),
the S-S stretching mode located at 679cm and first studied
by Lindenmayer textit{et al.} in 1986 (textit{J. Mol. Spectrosc.} textbf{119}, 56)
has been re-investigated at the French national synchrotron facility SOLEIL using Fourier-transform far-infrared spectroscopy.
In addition to the vibrational fundamental, evidence for at least one more hot band, most likely ,
was found. Complementary submillimeter wave measurements of the pure rotational
spectrum in the state were also performed
ISOTOPE INVARIANT FITTING OF GeO AND GeS AND THE 73Ge QUADRUPOLE MOMENT DERIVED FROM SPECTROSCOPY AND QUANTUM CHEMICAL CALCULATIONS
Diatomic germanium oxide, GeO, and germanium sulfide, GeS, have been studied by Fourier transform microwave spectroscopy
using laser ablation from a germanium target rod in the presence of HS or O diluted in neon.
Extensive isotopic spectroscopy has been performed; measurements include the ground vibrational state as well as states exceeding
for some species. Ground state rotational spectra of several GeS isotopologs have also been studied around 300\,GHz through a DC
discharge of GeCl and HS in a free-space absorption cell.
A global isotope invariant fit has been performed combining all previously published
and new high-resolution spectroscopic data. From the analysis of the Ge data combined with highly accurate quantum chemical values for the germanium electric-field gradient,
a revised Ge quadrupole moment has been derived
High-resolution infrared spectroscopy of carbon-sulfur chains: II. C5s and SC5S
Unbiased high-resolution infrared survey scans of the ablation products from carbon-sulfur targets in the 2100 to 2150\,cm regime
reveal two bands previously not observed in the gas phase. On the basis of comparison against laboratory matrix-isolation work\footnote{H. Wang, J. Szczepanski, P. Brucat, and M. Vala 2005, Int. J. Quant. Chem. 102, 795} and new high-level quantum-chemical calculations these bands are attributed to the linear CS and SCS clusters. While polar CS was studied earlier using Fourier-transform microwave techniques,\footnote{Y. Kasai, K. Obi, Y. Ohshima, Y. Hirahara, Y. Endo, K. Kawaguchi, and A. Murakami 1993, ApJ 410, L45}\footnote{V. D. Gordon, M. C. McCarthy, A. J. Apponi, and P. Thaddeus 2001, ApJS 134, 311} the present work marks the first gas-phase spectroscopic detection of SCS
DOPPLER AND SUB-DOPPLER MILLIMETER AND SUB-MILLIMETER WAVE SPECTROSCOPY OF KEY ASTRONOMICAL MOLECULES: HNC AND CS
In the course of ongoing efforts to determine accurate
pure rotational transition frequencies for the astronomical community, the millimeter- and submillimeter-wave spectra of HNC and selected isotopic species
have been investigated using a radio-frequency discharge of
(isotopically enriched) methyl cyanide.
Besides the ground vibrational state, vibrational satellites from
the first excited bending mode were targeted.
In part, rotational transitions were observed employing the Lamb-Dip technique
to obtain sub-Doppler resolution.
The Lamb-dip technique has also been applied to other short-lived molecules such as carbon monosulfide, CS
Synergy of multifrequency studies from observations of NGC6334I
We combine multifrequency observations from the millimeter to near infrared
wavelengths that demonstrate the spatial distributions of H2, CO, and NH3
emission, which are all manifestations of various shocks driven by outflows of
deeply embedded sources in NGC6334I. In addition to the well-known
northeast-southwest outflow we detect at least one more outflow in the region
by combining observations from APEX, ATCA, SMA, Spitzer and VLT/ISAAC.
Potential driving sources will be discussed. NGC6334I exhibits several signs of
active star formation and will be a major target for future observatories such
as Herschel and ALMA.Comment: 6 pages, 6 figures, appeared in the proceedings of the workshop 'The
Universe Under The Microscope - Astrophysics At High Angular Resolution', see
http://www.iop.org/EJ/toc/1742-6596/131/
Generation and structural characterization of Ge carbides GeCn ( n = 4, 5, 6) by laser ablation, broadband rotational spectroscopy, and quantum chemistry
International audienc
MICROWAVE DETECTION OF PROTONATED SO IN TWO ISOMERIC FORMS
Author Institution: Harvard-Smithsonian Center for Astrophysics, 60 Garden St.; Cambridge, MA 02138, and School of Engineering \& Applied Sciences, Harvard University, 29 Oxford St., Cambridge, MA 02138; Max-Planck-Institut fur Radioastronomie, Auf dem Hugel 69, 53121 Bonn, GermanyBy means of Fabry-Perot FT microwave spectroscopy, the rotational spectrum of protonated sulfur dioxide in two distinct isomeric forms, a \textit{cis} and a \textit{trans} geometry, is reported. Searches for both isomers were based on theoretical structures obtained at the CCSD(T)/cc-pwCVQZ level of theory corrected for zero-point vibrational effects at the CCSD(T)/cc-pV(T+)Z level. At a similarly high level of theory, the \textit{cis} isomer is calculated to be the global minimum on the potential energy surface, but the \textit{trans} isomer is predicted to lie only a few kcal/mol higher in energy. The identification of \textit{cis} HOSO has been confirmed by detection of rotational lines of DOSO and HOSO at precisely the expected frequency shifts. Because sulfur dioxide is a well known interstellar and extragalactic species, and because it possesses a large proton affinity, HOSO is a excellent candidate for radioastronomical detection
- …