Radioastronomical observations of comets IRAS-Araki-Alcock (1983d) and Sugano-Saigusa-Fujikawa (1983e)

Irvine, William M.; Abraham, Z.; A’Hearn, Michael F.; Altenhoff, W. J.; Andersson, C.; Bally, John; Batrla, W.; Baudry, A.; Bockelée‐Morvan, Dominique; Chin, G.; Crovisier, J.; Pater, Imke de; Despois, D.; Ekelund, Lars‐Göran; Gérard, E.; Hasegawa, Tetsuo; Heiles, Carl; Hollis, J. M.; Huchtmeier, W. K.; Kaifu, Norio; Levreault, R. M.; Masson, C. R.; Palmer, Patrick; Pérault, M.; Rickard, L. J.; Sargent, Anneila I.; Scalise, E.; Schloerb, F. P.; Schmidt, J.; Stark, A. A.; Stevens, M.; Stumpff, P.; Sutton, E. C.; Swade, Daryl A.; Sykes, M. V.; Turner, B. E.; Wade, C. M.; Walmsley, M.; Webber, J. C.; Winnberg, A.; Wootten, Alwyn

doi:10.1016/0019-1035(84)90150-7

Cited by 19 publications

(5 citation statements)

References 11 publications

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“…a Since we only have an upper limit to the diameter, this is a lower limit to the areal flux and active fraction. If the diameter is really 1 km, then this flux is 0.30 and the active fraction is 0.05. d Irvine et al (1984). The reported detections were very low SNR.…”

Section: Discussionmentioning

confidence: 85%

Detection of large grains in the coma of Comet C/2001 A2 (LINEAR) from Arecibo radar observations

Nolan

Harmon

Howell

et al. 2006

Icarus

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Arecibo S-band (λ = 13 cm) radar observations of Comet C/2001 A2 (LINEAR) on 2001 July 7-9 showed a strong echo from large coma grains. This echo was significantly depolarized. This is the first firm detection of depolarization in a grain-coma radar echo and indicates that the largest grains are at least λ/2 or 2 cm in radius. The grains are moving at tens of m s −1 with respect to the nucleus. The non-detection of the nucleus places an upper limit of 3 km on its diameter. The broad, asymmetric echo power spectrum suggests a fan of grains that have a steep (differential number ∼ a −4 ) size distribution at cm-scales, though the observed fragmentation of this comet complicates that picture.

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Section: Discussionmentioning

confidence: 85%

Detection of large grains in the coma of Comet C/2001 A2 (LINEAR) from Arecibo radar observations

Nolan

Harmon

Howell

et al. 2006

Icarus

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“…Detection of the J=l-0 lines of HCN at 89 GHz in Comet Kohoutek 1973 XII was announced by Huebner et al (1974). Subsequent searches in other comets with a higher sensitivity were negative, or at most gave marginal results (Irvine et al 1984;. However, the presence of HCN in comets was confirmed when the HCN radio lines were finally unambiguously detected in P/Halley (see, e.g., Figure 4) by three radio telescopes (Despois et al 1986;Schloerb et al 1986Schloerb et al , 1987bBockelee-Morvan et al 1987;Winnberg et al 1987) and monitored for nearly six months.…”

Section: Other Molecular Speciesmentioning

confidence: 99%

The Study of Comets at Radio Wavelengths

Crovisier¹,

Schloerb²

1989

International Astronomical Union Colloquium

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Radio observations of comets complement studies at other wavelengths as well as providing certain kinds of unique information. Studies of continuum emission may probe the thermal emission of the nucleus and large-size dust particles. Spectroscopic observations of gas in the coma allow searches for parent molecular species that have no signatures in the optical spectral range. The 18-cm wavelength spectral lines of the OH radical now are relatively easy to detect, and observations of them permit long-term and short-term monitoring of the cometary gaseous output. Moreover, with the unique spectral resolution of radio techniques, aspects of the kinematics of the coma may be also studied, such as the gas expansion velocity and the anisotropy of gas production from the nucleus. In this review, we present recent results of cometary radio observations, and discuss what may be learned from such studies in the future.

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“…The cyanoacetylene molecule (HCCCN or HC 3 N) has been identified in the interstellar medium (ISM) through microwave spectroscopy [1], due to its strong permanent dipole moment. HCCCN has also been observed in the carbon/ nitrogen-rich atmosphere of Titan [2], interstellar gas clouds [3,4], comets [5,6] and circumstellar envelopes [7]. Vibrationally excited spectra of the molecule have been used for the derivation of important physical properties of a protoplanetary nebula [8].…”

Section: Introductionmentioning

confidence: 99%

Cross-section studies of cyanoacetylene by electron impact

Kaur

Mason

Antony

2016

J. Phys. B: At. Mol. Opt. Phys.

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The present article provides the first comprehensive study of electron scattering from the cyanoacetylene molecule. The results reported here include integral elastic cross-sections over a wide energy range (0.5 to 5000 eV) and differential, momentum transfer and electronic excitation cross-sections at low energies (<10 eV). For the computation of cross-sections over such a wide energy range, two formalisms are employed: the ab initio R-matrix method and the spherical complex-optical-potential method operating at low and high incident energies, respectively. The total ionization cross-section has also been calculated using the complex scattering potential-ionization contribution method and shows excellent agreement with previously reported values. The target parameters and resonance positions predicted by the R-matrix method are in reasonable agreement with, albeit limited, previous data. The resonances identified at low energies are associated to several dissociative electron-attachment channels.

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Radioastronomical observations of comets IRAS-Araki-Alcock (1983d) and Sugano-Saigusa-Fujikawa (1983e)

Cited by 19 publications

References 11 publications

Detection of large grains in the coma of Comet C/2001 A2 (LINEAR) from Arecibo radar observations

Detection of large grains in the coma of Comet C/2001 A2 (LINEAR) from Arecibo radar observations

The Study of Comets at Radio Wavelengths

Cross-section studies of cyanoacetylene by electron impact

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