J/A+A/656/A160 Comet C/2020 F3 (NEOWISE) emission lines (Cambianica+, 2021)
A high-spectral-resolution catalog of emission lines in the visible spectrum
of comet C/2020 F3 (NEOWISE).
Cambianica P., Cremonese G., Munaretto G., Capria M. T., Fulle M.,
Boschin W., Di Fabrizio L., Harutyunyan A.
<Astron. Astrophys. 656, A160 (2021)>
=2021A&A...656A.160C 2021A&A...656A.160C (SIMBAD/NED BibCode)
ADC_Keywords: Solar system ; Comets ; Spectroscopy
Keywords: comets: general - comets: individual: C/2020 F3 (NEOWISE) -
methods: observational - data analysis
Abstract:
Comet C/2020 F3 (NEOWISE) is considered to be the brightest comet
observed in the northern hemisphere since the passage of comet
C/1995 O1 (Hale-Bopp) in 1997. Since the study of comets offers a
unique opportunity to investigate the early stages of the formation
and evolution of our Sun and the Solar System, we obtained
high-resolution optical spectra (R=λ/Δλ=115000) of
comet NEOWISE. The unique passage and its brightness yielded spectra
with a large number of emission lines, providing information on the
coma composition and the physical and chemical processes occurring in
the nucleus. The spectra have been used to generate a catalog of
emission lines to be used for future studies of comets since there are
no catalogs in the literature with such a high spectral resolution.
Two high-resolution spectra of comet NEOWISE were obtained, on 26 July
2020 (geocentric distance of 0.7au) and 5 August 2020 (geocentric
distance of 0.89au), with the High Accuracy Radial velocity Planet
Searcher for the Northern hemisphere (HARPS-N) echelle spectrograph
installed on the 360cm Telescopio Nazionale Galileo (TNG). The
spectra cover the range between 383 and 693nm, and have been
extracted using the HARPS-N Data Reduction Pipeline. To analyze the
spectra and compile the high-resolution catalog, we collected several
laboratory molecular line lists that cover the same wavelength range
as that of our spectra. To validate the final identification, we
compared our catalog with other atlases that resulted from the
spectral analysis of other comets.
We generate a high-spectral-resolution catalog of emission lines
observed in comet NEOWISE, providing the identification for 4488
lines. We found cometary lines due to CN, CH, C2, C3, and NH2
and atomic lines due to NaI and [OI].
Description:
The catalog is based on the spectral extraction performed
automatically by the HARPS-N Data Reduction pipeline. The basic
processing steps consist in bias subtraction (the bias is computed on
the over-scan regions of the frame), spectrum extraction, flat
fielding, wavelength calibration, and normalization of the blaze
continuum. The blaze-corrected spectrum is derived by dividing the
extracted order spectra by the blaze function. The dust-scattered
solar light is removed using a high-resolution solar analogue spectrum
(Land 107-684) degraded to the same spectral resolution. Table C1
reports the wavelength corresponding to the sky emission and the
relative intensity. Table C2 provides the observed wavelength
(λ), the relative intensity (Irel), the name of the
molecule, and the transition (if mentioned in the reference).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablec1.dat 23 984 Sky emission-lines (wavelength corresponding
to the sky emission and the relative intensity)
tablec2.dat 56 5193 High-resolution catalog of comet
C/2020 F3 (NEOWISE)
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Byte-by-byte Description of file: tablec1.dat tablec2.dat
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Bytes Format Units Label Explanations
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1- 11 F11.6 0.1nm Lambda Wavelength
13- 23 F11.5 --- Irel Relative Intensity
29- 40 A12 --- Mol Molecule (only in tablec2.dat)
42- 56 A15 --- Trans Transition (only in tablec2.dat)
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Acknowledgements:
Pamela Cambianica, pamela.cambianica(at)inaf.it
(End) Pamela Cambianica [Inaf-OAPD], Patricia Vannier [CDS] 14-Oct-2021