J/A+A/393/1053 18-cm OH lines in comets (Crovisier+, 2002)
Observations at Nancay of the OH 18-cm lines in comets.
The data base. Observations made from 1982 to 1999.
Crovisier J., Colom P., Gerard E., Bockelee-Morvan D., Bourgois G.
<Astron. Astrophys. 393, 1053 (2002)>
=2002A&A...393.1053C 2002A&A...393.1053C
ADC_Keywords: Solar system ; Radio lines ; Comets
Keywords: comets: general - radio lines: solar system - solar system: general
Abstract:
Since the apparition of comet Kohoutek 1973 XII, the 18-cm lines of
the OH radical have been systematically observed in a number of comets
with the Nancay radio telescope. Between 1973 and 1999, 52 comets have
been successfully detected. This allowed an evaluation of the cometary
water production rates and their evolution with time, as well as a
study of several physical processes such as the excitation mechanisms
of the OH radio lines, the expansion of cometary atmospheres, their
anisotropy in relation to non-gravitational forces, and the Zeeman
effect in relation to the cometary magnetic field. Part of these
observations and their analysis have already been published. The bulk
of the results are now organized in a data base. The present paper is
a general presentation of the Nancay cometary data base and a more
specific description of the observations of 53 cometary apparitions
between 1982 and 1999. Comets observed before 1982 are only partly
incorporated in the data base. Observations of comets since 2000 have
benefited from a major upgrade of the telescope; they will be
presented in forthcoming publications.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
index.dat 62 53 Name of studied comets
tablesa.dat 152 266 Sum spectrum informations
tablesb.dat 152 2422 Single spectrum informations
tablesc.dat 115 423 Spectrum taken at an offset position
(for 11, 23, 28 and 44)
spectra/* . 3113 *Individual spectra
comete.tar 1606 389977 Original files
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Note on spectra/*: All spectra shown in figures and archived on files at
the CDS have been Hanning smoothed. Therefore, adjacent channels have
correlated noise. This should be taken into consideration when
evaluating noise and errors (this has been taken into account in the
errors listed in the tables).
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See also:
http://wwwusr.obspm.fr/~crovisie/basecom : The data base
Byte-by-byte Description of file: index.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq Sequential number of the comet
6- 16 A11 --- Name1 Old-style definitive designation
18- 23 A6 --- Name2 Od-style provisional designation
25- 64 A40 --- Name3 New-style designation
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Byte-by-byte Description of file: tablesa.dat tablesb.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq Sequential number of the comet
(see index.dat)
4- 11 A8 "YY/MM/DD" Date1 Date of observation (single spectrum) or
first date of range of integration
(sum spectrum)
12- 14 F3.2 d Date1d Fraction of day
15 A1 --- --- [-]
16- 23 A8 "YY/MM/DD" Date2 Last date of range of integration
(sum spectrum)
25- 29 F5.2 AU delta Geocentric distance
31- 34 F4.2 AU r Heliocentric distance
36- 40 F5.1 km/s HRV Heliocentric radial velocity
42- 46 F5.2 --- inv1 OH maser population inversion (model of
Despois et al., 1981A&A....99..320D 1981A&A....99..320D (G1)
48- 52 F5.2 --- inv2 OH maser inversion (model of Schleicher &
A'Hearn, 1988ApJ...331.1058S 1988ApJ...331.1058S) (G1)
54- 57 F4.1 K Tbg Background brightness temperature
59- 63 I5 mJy.km/s area Line area
65- 67 I3 mJy.km/s e_area rms error on line area
69- 73 I5 mJy S ? Line maximum intensity
75- 77 I3 mJy e_S ? rms error on line maximum intensity
79- 85 F7.2 km/s Vo ? Line central velocity
87- 91 F5.2 km/s e_Vo ? rms error on line central velocity
93- 99 F7.2 km/s dVo ? Line width at half maximum
101-105 F5.2 km/s e_dVo ? rms error on line width at half maximum
107 A1 --- l_Q[OH] Limit flag on Q[OH] (1)
108-113 F6.1 10+28s-1 Q[OH] ? OH production rate (Haser-eq. model with
quenching)
115-118 F4.1 10+28s-1 e_Q[OH] ? rms error on OH production rate
120 A1 --- l_Q[OH]2 Limit flag on Q[OH]2 (1)
121-128 F8.1 10+28s-1 Q[OH]2 ? OH production rate (1986A model)
130-133 F4.1 10+28s-1 e_Q[OH]2 ? rms error on OH production rate
135-140 A6 --- Fig Figure number (in electronic version of the
paper)
142-152 A11 --- SpFile Spectrum file name in sub-directory
spectra (G2)
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Note (1): Upper limit for entry without detected line
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Byte-by-byte Description of file: tablesc.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq Sequential number of the comet
(see index.dat)
4- 11 A8 "YY/MM/DD" Date Date of observation YYYY/MM/DD.DD
12- 14 F3.2 d Dated Fraction of day
16- 19 F4.2 AU delta Geocentric distance
21- 24 F4.2 AU r Heliocentric distance
26- 30 F5.1 km/s HRV Heliocentric radial velocity
32- 36 F5.2 --- inv1 OH maser inversion (model of Despois et al.,
Despois et al., 1981A&A....99..320D 1981A&A....99..320D (G1)
38- 42 F5.2 --- inv2 OH maser inversion (model of Schleicher &
A'Hearn, 1988ApJ...331.1058S 1988ApJ...331.1058S) (G1)
44- 46 F3.1 K Tbg Background brightness temperature
48- 52 I5 mJy.km/s area Line area
54- 56 I3 mJy.km/s e_area rms error on line area
58- 61 I4 mJy S ? Line maximum intensity
63- 64 I2 mJy e_S ? rms error on line maximum intensity
66- 70 F5.2 km/s Vo ? Line central velocity
72- 75 F4.2 km/s e_Vo ? rms error on line central velocity
77- 80 F4.2 km/s dVo ? Line width at half maximum
82- 85 F4.2 km/s e_dVo ? rms error on line width at half maximum
87- 91 F5.1 arcmin oRA Offset in right ascension
93- 96 F4.1 arcmin oDE Offset in declination
98-103 A6 --- Fig Figure number (in electronic version of the
paper)
105-115 A11 --- SpFile Spectrum file name in sub-directory
spectra (G2)
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Byte-by-byte Description of file: spectra/*
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Bytes Format Units Label Explanations
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1- 15 E15.6 km/s Vel Velocity
17- 30 E14.7 Jy Flux Flux in Jy/beam
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Global notes:
Note (G1): Population inversion is defined by i=(Nu-Nl)/(Nu+Nl), where
Nu and Nl are the densities of upper and lower levels respectively.
Note (G2): The spectra names are in the form cctnnnn.dat, where
cc is the sequential number of the comet (see index.dat)
t is the code for the type of spectra
i: individual spectra (tablesb.dat)
s: sum spectra (tablesa.dat)
d: offset spectra (tablesc.dat)
nnnn is the sequential number
Comments on printer paper:
The correct url for the database website at Meudon is
http://wwwusr.obspm.fr/~crovisie/basecom/ instead of
http://www.usr.obspm.fr/~crovisie/basecom/
Comments on Online material at EDPS:
Commet 19P/Borrelly: the first sum spectrum in Fig. A.35a
is erroneous (the last individual spectrum is shown instead).
This has been corrected in the CDS data.
In some cases, the names of the comets which appear on the
figures of the Appendix correspond to provisional designations.
This has been corrected in the CDS data.
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Acknowledgements: Jacques Crovisier
(End) Patricia Bauer [CDS] 14-Oct-2002