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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
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:
FileName Lrecl Records Explanations
ReadMe 80 . This file index.dat 64 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/* 30 3113 *Individual spectra comete.tar 1606 389977 Original files
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).
See also: http://wwwusr.obspm.fr/~crovisie/basecom : The data base Byte-by-byte Description of file: index.dat
Bytes Format Units Label Explanations
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
Byte-by-byte Description of file: tablesa.dat tablesb.dat
Bytes Format Units Label Explanations
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 (G1) 48- 52 F5.2 --- inv2 OH maser inversion (model of Schleicher & A'Hearn, 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)
Note (1): Upper limit for entry without detected line
Byte-by-byte Description of file: tablesc.dat
Bytes Format Units Label Explanations
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 (G1) 38- 42 F5.2 --- inv2 OH maser inversion (model of Schleicher & A'Hearn, 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)
Byte-by-byte Description of file: spectra/*
Bytes Format Units Label Explanations
1- 15 E15.6 km/s Vel Velocity 17- 30 E14.7 Jy Flux Flux in Jy/beam
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. Acknowledgements: Jacques Crovisier
(End) Patricia Bauer [CDS] 14-Oct-2002
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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