Rotational spectroscopy of the two higher energy conformers of 2-cyanobutane

Laboratory spectroscopic data of large and complex molecules are of upmost importance for the astronomy community to detect new molecular species in space and to achieve a greater understanding of the chemistry involved in star forming regions and processes. In our publication we present high-resolution rotational spectroscopy of the two higher energy conformers of 2- cyanobutane (C4H9CN), a a member of a larger family of cyanides.

Velocity profiles of [CII], [CI], CO, and [OI] and physical conditions in four star-forming regions in the Large Magellanic Cloud

We report the first velocity-resolved observations of atomic oxygen in the Large Magellanic Cloud (LMC) seen in emission lines at a wavelength of 63 and 145 micrometers. The line profiles neither match those from ionized carbon nor from carbon monoxide. This confirms that clouds in very different physical conditions co-exist within the observing beam.

The Origin of [C II] 158 μm Emission toward the HII Region Complex S235

Geometry of S235 resolved from SOFIA observations of ionized carbon

Velocity-resolved observations of ionized carbon in the HII-region S235 show that, although most of the radiation comes from the direction of ionized hydrogen, it has a different velocity than the ionized hydrogen. Practically the emission does not come from the same gas, but from photon-dominated dense gas behind the HII region.

Accurate Rotational Rest Frequencies for Ammonium Ion Isotopologues

We report rest frequencies for rotational transitions of the deuterated ammonium isotopologues NH3D+, NH2D2+, and NHD3+, measured in a cryogenic ion trap machine. For the symmetric tops NH3D+ and NHD3+, one and three transitions are detected, respectively, and five transitions are detected for the asymmetric top NH2D2+.

The First Laboratory Detection of Vibration-rotation Transitions of 12CH+ and 13CH+ and Improved Measurement of Their Rotational Transition Frequencies

C–H stretches of the fundamental ions CH+ and 13CH+, which have long been searched for, have been observed for the first time in the laboratory. The state-dependent attachment of He atoms to these ions at cryogenic temperatures has been exploited to obtain high-resolution rovibrational data. In addition, the lowest rotational transitions of CH+13CH+ and CD+ have been revisited and their rest frequency values have improved substantially.

Spectroscopy of the low-frequency vibrational modes of CH3+ isotopologues

The low-frequency stretching and bending vibrations of the isotopologues  and  have been recorded at low temperature and low resolution. For this, a cryogenic 22-pole trapping machine coupled to an IR beamline of the FELIX free electron laser facility has been used. To record the overview spectra, the laser induced reactions have been applied for these species. As this scheme is not applicable to , the latter has been tagged with He and subsequently dissociated by the IR beam.

The complex chemistry of hot cores in Sagittarius B2(N): Influence of cosmic-ray ionization and thermal history

This article analyzes the chemical composition of a sample of hot molecular cores detected with ALMA in the high-mass star forming region Sgr B2(N). It shows that a cosmic-ray ionization rate enhanced by a factor 50 best reproduces the observed abundance ratios of various complex organic molecules.

https://arxiv.org/abs/1906.04695