Microwave Spectra of 11 Polyyne Carbon Chains

McCarthy, Michael; Chen, W.; Travers, Michael J.; Thaddeus, P.

doi:10.1086/313428

Cited by 158 publications

(140 citation statements)

References 27 publications

Supporting

Mentioning

130

Contrasting

Unclassified

Order By: Relevance

“…HOCN was first detected in the centimeter-wave band via its fundamental 1 0,1 -0 0,0 transition at 21 GHz in our Fourier transform microwave (FTM) spectrometer (McCarthy et al 2000). The discharge conditions were optimized on the corresponding transition of HNCO, which was produced in a 900 V DC discharge in the throat of the supersonic nozzle of the spectrometer through a mixture of water (0.035%), and cyanogen (NCCN, 0.03%) or methyl cyanide (CH 3 CN, 0.12%) heavily diluted in neon.…”

Section: Laboratory Measurements and Resultsmentioning

confidence: 99%

LABORATORY DETECTION OF HOCN AND TENTATIVE IDENTIFICATION IN Sgr B2

Brünken

Gottlieb

McCarthy

et al. 2009

ApJ

Self Cite

View full text Add to dashboard Cite

The rotational spectrum of cyanic acid, HOCN, has been detected in the centimeter-wave band in a molecular beam by Fourier transform microwave spectroscopy and in the millimeter-wave band by conventional spectroscopy in a low-pressure laboratory discharge. Spectroscopic constants, including the nitrogen hyperfine coupling constant, derived from 31 a-type transitions between 21 and 360 GHz with J up to 17 and K a 2 allow the spectrum in the only rotational ladders populated in the interstellar gas to be calculated well into the submillimeter-wave band to 1 km s −1 or better in equivalent radial velocity. Four consecutive transitions of HOCN between 83.9 and 146.8 GHz were tentatively identified in published spectral line surveys of Sgr B2(OH). An approximate column density in Sgr B2(OH) of 6 × 10 12 cm −2 implies that the HOCN/ HNCO ratio is about 0.5%. Because HNCO is widely distributed in the interstellar gas, HOCN may be as well.

show abstract

Section: Laboratory Measurements and Resultsmentioning

confidence: 99%

LABORATORY DETECTION OF HOCN AND TENTATIVE IDENTIFICATION IN Sgr B2

Brünken

Gottlieb

McCarthy

et al. 2009

ApJ

Self Cite

View full text Add to dashboard Cite

show abstract

“…The present apparatus has been described in detail previously (McCarthy et al 2000;Gottlieb et al 2003). In the centimeterwave band, HSCN was produced in the throat of a pulsed supersonic discharge nozzle.…”

Section: Laboratory Measurements and Resultsmentioning

confidence: 99%

Laboratory Detection of Thiocyanic Acid HSCN

Brünken

Gottlieb

et al. 2009

ApJ

Self Cite

View full text Add to dashboard Cite

The rotational spectrum of thiocyanic acid HSCN, a highly polar isomer of the well-known astronomical molecule isothiocyanic acid HNCS, has been measured in two radio bands: in the centimeter-wave band by Fourier transform microwave spectroscopy in a molecular beam, and in the millimeter-wave band by long-path absorption spectroscopy in a low-pressure glow discharge. Twelve spectroscopic constants were derived from more than 60 a-type rotational transitions between 11 and 346 GHz with J up to 30 and K a 6, including seven centimeter-wave transitions with resolved hyperfine structure. With these constants the rotational spectrum in the K a = 0 and K a = 1 ladders-those most likely to be observed in space-can now be calculated up to 400 GHz with formal uncertainties of less than 0.2 km s −1 in equivalent radial velocity. Thiocyanic acid was recently identified in Sgr B2 by Halfen et al. following the laboratory measurements, and there is possible evidence for it in cold dark clouds, with the implication that HSCN may be detectable in many galactic sources.

show abstract

“…Following the spectroscopic identification of the 2 Σ and 2 Δ components of vibrationally excited C 6 H at millimeter wavelengths, rotational lines were observed in a supersonic molecular beam at centimeter wavelengths with the laboratory's Fourier transform microwave spectrometer (McCarthy et al 2000). As in the millimeter-wave detection, the conditions that produced ground-state lines of C 6 H with optimum intensity resulted in the most intense lines of the 2 Σ component: a 1000 V discharge through a 0.2% sample of diacetylene (HC 4 H) in Ne in the throat of a supersonic nozzle (McCarthy et al Notes.…”

Section: Centimeter-wave Measurementsmentioning

confidence: 99%

VIBRATIONALLY EXCITED C ₆ H

Gottlieb¹,

McCarthy²,

Thaddeus³

2010

ApJS

Self Cite

View full text Add to dashboard Cite

Rotational spectra of the linear carbon chain radical C 6 H in two low-lying excited vibrational states were observed both at millimeter wavelengths in a low-pressure glow discharge and at centimeter wavelengths in a supersonic molecular beam. Two series of harmonically related lines with rotational constants within 0.3% of the 2 Π ground state were assigned to the 2 Σ and 2 Δ vibronic components of an excited bending vibrational level. Measurements of the intensities of the lines in the glow discharge indicate that the 2 Σ component lies very close to ground, but the 2 Δ component is much higher in energy. The standard Hamiltonian for an isolated 2 Δ state with five spectroscopic constants reproduces the observed rotational spectrum, but several high-order distortion terms in the spin-rotation interaction are needed to reproduce the spectrum of the 2 Σ component in C 6 H and C 6 D. The derived spectroscopic constants allow astronomers to calculate the rotational spectra of the 2 Σ and 2 Δ states up to 260 GHz to within 0.1 km s −1 or better in equivalent radial velocity.

show abstract

Microwave Spectra of 11 Polyyne Carbon Chains

Cited by 158 publications

References 27 publications

LABORATORY DETECTION OF HOCN AND TENTATIVE IDENTIFICATION IN Sgr B2

LABORATORY DETECTION OF HOCN AND TENTATIVE IDENTIFICATION IN Sgr B2

Laboratory Detection of Thiocyanic Acid HSCN

VIBRATIONALLY EXCITED C ₆ H

Contact Info

Product

Resources

About

Microwave Spectra of 11 Polyyne Carbon Chains

Cited by 158 publications

References 27 publications

LABORATORY DETECTION OF HOCN AND TENTATIVE IDENTIFICATION IN Sgr B2

LABORATORY DETECTION OF HOCN AND TENTATIVE IDENTIFICATION IN Sgr B2

Laboratory Detection of Thiocyanic Acid HSCN

VIBRATIONALLY EXCITED C 6 H

Contact Info

Product

Resources

About

VIBRATIONALLY EXCITED C ₆ H