Sub-Doppler Measurements on the Rotational Transitions of Carbon Monoxide

Winnewisser, G.; Belov, S. P.; Klaus, Th.; Schieder, R.

doi:10.1006/jmsp.1997.7341

Cited by 114 publications

(83 citation statements)

References 12 publications

(5 reference statements)

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“…The entries are based on Winnewisser et al (1997), Cazzoli et al (2004), Klapper et al (2001Klapper et al ( , 2003Klapper et al ( , 2000, and Klapper et al (2003), respectively.…”

Section: Carbon Monoxide Comentioning

confidence: 99%

Complex organic molecules in the interstellar medium: IRAM 30 m line survey of Sagittarius B2(N) and (M)

Беллоче

Müller

Menten

et al. 2013

A&A

385

523

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Context. The discovery of amino acids in meteorites fallen to Earth and the detection of glycine, the simplest of them, in samples returned from a comet to Earth strongly suggest that the chemistry of the interstellar medium is capable of producing such complex organic molecules and that they may be widespread in our Galaxy. Aims. Our goal is to investigate the degree of chemical complexity that can be reached in the interstellar medium, in particular in dense star-forming regions. Methods. We performed an unbiased, spectral line survey toward Sgr B2(N) and (M), two regions where high-mass stars are formed, with the IRAM 30 m telescope in the 3 mm atmospheric transmission window. Partial surveys at 2 and 1.3 mm were performed in parallel. The spectra were analyzed with a simple radiative transfer model that assumes local thermodynamic equilibrium but takes optical depth effects into account. Results. About 3675 and 945 spectral lines with a peak signal-to-noise ratio higher than 4 are detected at 3 mm toward Sgr B2(N) and (M), i.e. about 102 and 26 lines per GHz, respectively. This represents an increase by about a factor of two over previous surveys of Sgr B2. About 70% and 47% of the lines detected toward Sgr B2(N) and (M) are identified and assigned to 56 and 46 distinct molecules as well as to 66 and 54 less abundant isotopologues of these molecules, respectively. In addition, we report the detection of transitions from 59 and 24 catalog entries corresponding to vibrationally or torsionally excited states of some of these molecules, respectively, up to a vibration energy of 1400 cm −1 (2000 K). Excitation temperatures and column densities were derived for each species but should be used with caution. The rotation temperatures of the detected complex molecules typically range from ∼50 to 200 K. Among the detected molecules, aminoacetonitrile, n-propyl cyanide, and ethyl formate were reported for the first time in space based on this survey, as were five rare isotopologues of vinyl cyanide, cyanoacetylene, and hydrogen cyanide. We also report the detection of transitions from within twelve new vibrationally or torsionally excited states of known molecules. Absorption features produced by diffuse clouds along the line of sight are detected in transitions with low rotation quantum numbers of many simple molecules and are modeled with ∼30-40 velocity components with typical linewidths of ∼3-5 km s −1 . Conclusions. Although the large number of unidentified lines may still allow future identification of new molecules, we expect most of these lines to belong to vibrationally or torsionally excited states or to rare isotopologues of known molecules for which spectroscopic predictions are currently missing. Significant progress in extending the inventory of complex organic molecules in Sgr B2(N) and deriving tighter constraints on their location, origin, and abundance is expected in the near future thanks to an ongoing spectral line survey at 3 mm with ALMA in its cycles 0 and 1. The present single-dish surve...

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“…The entries are based on Winnewisser et al (1997), Cazzoli et al (2004), Klapper et al (2001Klapper et al ( , 2003Klapper et al ( , 2000, and Klapper et al (2003), respectively.…”

Section: Carbon Monoxide Comentioning

confidence: 99%

Complex organic molecules in the interstellar medium: IRAM 30 m line survey of Sagittarius B2(N) and (M)

Беллоче

Müller

Menten

et al. 2013

A&A

385

523

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“…Besides, this measurement accuracy can be increased to ±500 Hz in cases where sub-Doppler measurements are possible [12]. The PS spectra have been measured with less accuracy because of a variety of reasons such as partial blending for nearly all hyperfine components of PS, baseline problems, and the rather low production rate of the PS molecule.…”

Section: \ N »Imentioning

confidence: 99%

Rotational Spectra of Phosphorus Monosulfide up to 1 THz

Klein

Klisch

Winnewisser

1999

Zeitschrift Für Naturforschung A

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The submillimeter-wave rotational spectrum of the PS radical in the electronic and vibrational ground state (A' 2 77I/ 2 , X 2 IJ 3 / 2 ) was recorded with the Cologne terahertz spectrometer in the frequency region between 540 GHz and 1.07 THz, covering rotational quantum numbers from J = 30.5 to 60.5. The PS radical has been produced by discharging PSC1 3 buffered with Ar. For all transitions the yl-doubling was resolved for both the 2 77I/2 and 2 77 3 / 2 states. For some transitions with AF = 0 the hyperfine structure (hfs) caused by the P-atom could partially be resolved even for rather high J values. Analysis of the complete rotational data set of PS allows the derivation of a full set of molecular parameters, including the rotational constants B, D, H, the fine-structure constants A, 7, D 1 , the parameters for the yl-doubling p, D p , q, and the magnetic hyperfine constants a, b, c, d, Ci. All parameters have been determined, whereby a, c, and the nuclear spin rotation-constant Ci were obtained for the first time.

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“…The Doppler-limited measurements can be trusted to 5 kHz. The achievable accuracy for unblended, fully resolved Lamb dip measurements in the sub-millimeter wave region recorded with a good signal to noise ratio is estimated to be around 500 Hz [2], However, the present accuracies are estimated to be about 2 kHz, i.e. somewhat lower than the achievable 500 Hz.…”

Section: Resultsmentioning

confidence: 57%

“…In contrast to the main isotopomer of carbon monoxide 12 C 16 0, [1,2], only a few publications of laboratory measurements have been reported in literature for l3 C l8 0. Sub-Doppler measurements on CO were presented in 1997 by Winnewisser et al [2] …”

Section: Introductionmentioning

confidence: 99%

Sub-Doppler Measurements and Rotational Spectrum of ¹³C¹⁸O

Klapper

Lewen

Belova

et al. 2000

Zeitschrift Für Naturforschung A

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The rotational spectrum of n C lx O has been measured up to 1 THz. The lowest rotational transitions of 1l s O (J = 2 *-1 to J = 6 *-5) have been measured by saturation-dip spectroscopy with an experimental accuracy of 2 kHz. These five low J rotational transitions cover the frequency range between 209 and 628 GHz. The narrow linewidths of about 20 kHz of the saturation dips allowed to resolve the two main hyperfine components. The splitting is caused by coupling of the 1 C nuclear spin with the rotation of the molecule. The appropriate coupling constant C/(' C O) is 33.90(81) kHz.In addition we have measured in the Doppler limited mode, the line positions of the rotational transitions 7 = 7*-6,7 = 8*-7, and J = 9 *-8 with accuracies of 5 kHz. We provide a set of improved constants together with frequency predictions up to 4.1 THz (J = 40 *-39).

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Sub-Doppler Measurements on the Rotational Transitions of Carbon Monoxide

Cited by 114 publications

References 12 publications

Complex organic molecules in the interstellar medium: IRAM 30 m line survey of Sagittarius B2(N) and (M)

Complex organic molecules in the interstellar medium: IRAM 30 m line survey of Sagittarius B2(N) and (M)

Rotational Spectra of Phosphorus Monosulfide up to 1 THz

Sub-Doppler Measurements and Rotational Spectrum of ¹³C¹⁸O

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Sub-Doppler Measurements on the Rotational Transitions of Carbon Monoxide

Cited by 114 publications

References 12 publications

Complex organic molecules in the interstellar medium: IRAM 30 m line survey of Sagittarius B2(N) and (M)

Complex organic molecules in the interstellar medium: IRAM 30 m line survey of Sagittarius B2(N) and (M)

Rotational Spectra of Phosphorus Monosulfide up to 1 THz

Sub-Doppler Measurements and Rotational Spectrum of 13C18O

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Sub-Doppler Measurements and Rotational Spectrum of ¹³C¹⁸O