Journal ArticleDOI
Long-term Evolution of the Outgassing of Comet Hale-Bopp From Radio Observations
N. Biver,Dominique Bockelée-Morvan,P. Colom,Jacques Crovisier,B. Germain,Emmanuel Lellouch,John K. Davies,William R. F. Dent,R. Moreno,Gabriel Paubert,J. Wink,Didier Despois,Dariusz C. Lis,D. Mehringer,Dominic J. Benford,M. Gardner,Thomas G. Phillips,M. Gunnarsson,Hans Rickman,Anders Winnberg,Per Bergman,Lars E B Johansson,Heike Rauer +22 more
Reads0
Chats0
TLDR
In this article, the production rates of eight molecular species (CO, HCN, CH3OH, H2CO,H2S, CS, CH 3CN,HNC) have been monitored as a function of heliocentric distance.Abstract:
C/1995 O1 (Hale-Bopp) has been observed on a regular basis since August 1995 at millimetre and submillimetre wavelengths using IRAM, JCMT, CSO and SEST radio telescopes. The production rates of eight molecular species (CO, HCN, CH3OH, H2CO,H2S, CS, CH3CN,HNC) have been monitored as a function of heliocentric distance(rh from 7 AU pre-perihelion to 4 AU post-perihelion. As comet Hale-Bopp approached and receded from the Sun, these species displayed different behaviours. Far from the Sun, the most volatile species were found in general relatively more abundant in the coma. In comparison to other species, HNC, H2CO and CS showed a much steeper increase of the production rate with decreasing rh. Less than 1.5 AU from the Sun, the relative abundances were fairly stable and approached those found in other comets near 1 AU. The kinetic temperature of the coma, estimated from the relative intensities of the CH3OH and CO lines, increased with decreasing rh, from about10 K at 7 AU to 110 K around perihelion. The expansion velocity of the gaseous species, derived from the line shapes, also increased with a law close torh
3.read more
Citations
More filters
Journal ArticleDOI
The Chemical Composition of Comets—Emerging Taxonomies and Natal Heritage
TL;DR: A detailed survey of more than 100 comets has been carried out by as mentioned in this paper, which enabled taxonomic groupings based on free radical species and on crystallinity of rocky grains.
The composition of cometary volatiles
Abstract: The composition of cometary ices provides key information on the chemical and physical properties of the outer solar nebula where comets formed, 4.6 G.y. ago. This chapter summarizes our current knowledge of the volatile composition of cometary nuclei, based on spectroscopic observations and in situ measurements of parent molecules and noble gases in cometary comae. The processes that govern the excitation and emission of parent molecules in the radio, infrared (IR), and ultraviolet (UV) wavelength regions are reviewed. The techniques used to convert line or band fluxes into molecular production rates are described. More than two dozen parent molecules have been identified, and we describe how each is investigated. The spatial distribution of some of these molecules has been studied by in situ measurements, long-slit IR and UV spectroscopy, and millimeter wave mapping, including interferometry. The spatial distributions of CO, H2CO, and OCS differ from that expected during direct sublimation from the nucleus, which suggests that these species are produced, at least partly, from extended sources in the coma. Abundance determinations for parent molecules are reviewed, and the evidence for chemical diversity among comets is discussed.
Journal ArticleDOI
Astrophysical and astrochemical insights into the origin of life
Pascale Ehrenfreund,William M. Irvine,L. Becker,Jennifer G. Blank,John Robert Brucato,Luigi Colangeli,Sylvie Derenne,D. Despois,Anne Dutrey,H. Fraaije,Antonio Lazcano,Tobias Owen,François Robert +12 more
TL;DR: In this paper, the formation of organic molecules in space has been studied and the physical and chemical conditions, including density, temperature, ultraviolet (UV) radiation and energetic particles, have been used to determine reaction pathways and the complexity of organic molecule in different space environments.
Astrophysical and astrochemical insights into the origin of life
Pascale Ehrenfreund,William M. Irvine,L. Becker,Jennifer G. Blank,John Robert Brucato,Luigi Colangeli,Sylvie Derenne,D. Despois,Anne Dutrey,H. Fraaije,Antonio Lazcano,Tobias Owen,François Robert +12 more
TL;DR: In this paper, the formation of organic molecules in space has been studied and the physical and chemical conditions, including density, temperature, ultraviolet (UV) radiation and energetic particles, have been used to determine reaction pathways and the complexity of organic molecule in different space environments.
Journal ArticleDOI
The composition of ices in comet C/1995 O1 (Hale-Bopp) from radio spectroscopy - Further results and upper limits on undetected species
TL;DR: A review of radio spectroscopic observations of comets and further analysis of their results is presented in this article, where Bockelee-Morvan et al. present a spectral survey conducted at radio wavelengths in comet Hale-Bopp with the CSO, the IRAM 30-m telescope and Plateau de Bure interferometer.
References
More filters
Journal ArticleDOI
Evolution of the Outgassing of Comet Hale-Bopp (C/1995 O1) from Radio Observations
Nicolas Biver,Dominique Bockelée-Morvan,Pierre Colom,Jacques Crovisier,John K. Davies,William R. F. Dent,Didier Despois,E. Gérard,Emmanuel Lellouch,Heike Rauer,Raphael Moreno,Gabriel Paubert +11 more
TL;DR: Spectra obtained from ground-based radio telescopes show the progressive release of CO, CH3OH, HCN, H2O (from OH), H2S, CS, H 2CO, CH 3CN, and HNC as comet Hale-Bopp approached the sun from 6.9 to 1.4 astronomical units (AU).
Journal ArticleDOI
Photodestruction rates for cometary parent molecules
TL;DR: In this paper, the photodestruction rates for several molecules of cometary interest are evaluated, together with a critical comparison with other estimations, and a summary of the need for future laboratory measurements.
Journal ArticleDOI
Carbon Monoxide Outgassing from Comet P/Schwassmann-Wachmann 1
Jacques Crovisier,Nicolas Biver,Dominique Bockelée-Morvan,Pierre Colom,Laurent Jorda,Emmanuel Lellouch,Gabriel Paubert,Didier Despois +7 more
TL;DR: In this article, the authors observed the J (2-1) and (1-0) lines of CO in Comet P/Schwassmann-Wachmann 1 with high spectral resolution at four different epochs.
Journal ArticleDOI
HNC and HCN in Comets
TL;DR: In this paper, a multilinear hydrodynamical-chemical model of cometary comae was used to predict the HNC and HCN abundances in comets Hyakutake and Hale-Bopp for a variety of initial parameters.
Journal Article
The extended formaldehyde source in comet P/Halley
TL;DR: In this article, the authors derived the total production of formaldehyde and the strength of its extended source within the contact surface located at 4660 km from the neutral mass spectrometer on the Giotto spacecraft.