J/A+A/668/A171 Comet C/2020 F3 (NEOWISE) IRAM and NOEMA spectra (Biver+, 2022)
Observations of comet C/2020 F3 (NEOWISE) with the IRAM telescopes.
Biver N., Boissier J., Bockelee-Morvan D., Crovisier J., Cottin H.,
Cordiner M.A., Roth N.X., Moreno R.
<Astron. Astrophys. 668, A171 (2022)>
=2022A&A...668A.171B 2022A&A...668A.171B (SIMBAD/NED BibCode)
ADC_Keywords: Comets ; Radio lines ; Spectra, millimetric/submm
Keywords: comets: general - comets: individual: C/2020 F3 -
radio lines: planetary systems - radio continuum: planetary systems -
submillimeter: planetary systems
Abstract:
We present the results of millimetre-wave spectroscopic and continuum
observations of comet C/2020 F3 (NEOWISE) undertaken with the Institut
de RadioAstronomie Millimetrique (IRAM) 30-m and the NOrthern
Extended Millimeter Array (NOEMA) telescopes on 22, 25-27 July and 7
August 2020. Production rates of HCN, HNC, CH3OH, CS, H2CO,
CH3CN, H2S, and CO were determined with upper limits on 6 others
species. The comet shows abundances within the range observed in other
comets. The CO abundance is low (3.2% relative to water) while H2S
is relatively abundant (1.1% relative to water). The H2CO abundance
shows a steep variation with heliocentric distance, possibly related
to a distributed production from the dust or macro-molecular source.
The CH3OH and H2S production rates show a slower decrease
post-perihelion than water. Interferometric map of the continuum could
not detect the nucleus point source contribution (implying a size
r<4.7km) but yielded an estimate of the dust production rate, leading
to a relatively low dust-to-gas ratio of 0.7±0.3 on 22.4 July 2020.
Description:
Individual, time averaged, IRAM 30m and NOEMA telescope spectra as
presented in Figs. 4 to 11, 13, and 14, obtained with the FTS, VESPA
or POLYFIX correlators. One fits file per spectrum, fits output are
produced from class. (http://www.iram.fr/IRAMFR/GILDAS/).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 145 29 List of spectra
fits/* . 29 Individual spectra
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 24 I5 --- Nx Number of pixels along X-axis
26- 48 A23 "datime" Obs.date Observation date
50- 61 E12.6 Hz bFREQ Lower value of frequency interval
63- 73 E11.6 Hz BFREQ Upper value of frequency interval
75- 82 F8.1 Hz dFREQ Frequency resolution
84- 85 I2 Kibyte size Size of FITS file
87- 98 A12 --- FileName Name of FITS file, in subdirectory fits
100-145 A46 --- Title Title of the FITS file
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Acknowledgements:
Nicolas Biver, Nicolas.Biver(at)obspm.fr
(End) Patricia Vannier [CDS] 18-Nov-2022