NH2 and its parent molecule in the inner coma of comet Hyakutake (C/1996 B2)

被引:22
作者
Kawakita, H
Watanabe, J
机构
[1] Misato Observ, Wakayama 64013, Japan
[2] Natl Astron Observ Japan, Mitaka, Tokyo 181, Japan
关键词
comets; individual; (Hyakutake); molecular processes;
D O I
10.1086/305318
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Spectroscopic observations of comet Hyakutake (C/1996 B2) in the visible region was performed at Bisei Astronomical Observatory. The obtained spectrum covers the wavelengths from 5800 to 7300 Angstrom and includes several emissions of some NH2 bands, i.e., the (0, 7, 0), (0, 8, 0), and (0, 9, 0) bands. Comet Hyakutake was observed when it was fairly close to the Earth; the geocentric distance of the comet was Delta = 0.113 AU. The surface brightness profile of the inner coma in the vicinity of the nucleus was obtained at the sufficient spatial resolution. The collisions between the molecules are conspicuous in the region near the nucleus (where the nucleocentric distance is less than about 10(3) km). The random walk model, considering the collisions between molecules, is used to research the parent molecule of NH2 in this study. It is possible to examine whether each of the few candidates for the parent molecule of NH2 can explain the observed NH2 spatial profile. The result of our simulation supports the fact that NH3 is most likely to be the parent molecule of NH2.
引用
收藏
页码:946 / 950
页数:5
相关论文
共 20 条
[1]   NEUTRAL COMETARY ATMOSPHERES .1. AN AVERAGE RANDOM-WALK MODEL FOR PHOTO-DISSOCIATION IN COMETS [J].
COMBI, MR ;
DELSEMME, AH .
ASTROPHYSICAL JOURNAL, 1980, 237 (02) :633-640
[2]   THE OH DISTRIBUTION IN COMETARY ATMOSPHERES - A COLLISIONAL MONTE-CARLO MODEL FOR HEAVY SPECIES [J].
COMBI, MR ;
BOS, BJ ;
SMYTH, WH .
ASTROPHYSICAL JOURNAL, 1993, 408 (02) :668-677
[3]   MONTE-CARLO PARTICLE-TRAJECTORY MODELS FOR NEUTRAL COMETARY GASES .1. MODELS AND EQUATIONS [J].
COMBI, MR ;
SMYTH, WH .
ASTROPHYSICAL JOURNAL, 1988, 327 (02) :1026-1043
[4]  
FESTOU MC, 1987, ASTRON ASTROPHYS, V174, P299
[5]  
FESTOU MC, 1981, ASTRON ASTROPHYS, V95, P69
[6]   A survey of 39 comets using CCD spectroscopy [J].
Fink, U ;
Hicks, MD .
ASTROPHYSICAL JOURNAL, 1996, 459 (02) :729-743
[7]   THE TREND OF PRODUCTION-RATES WITH HELIOCENTRIC DISTANCE FOR COMET P/HALLEY [J].
FINK, U .
ASTROPHYSICAL JOURNAL, 1994, 423 (01) :461-473
[8]   COMET SUGANO-SAIGUSA-FUJIKAWA (1983V) - A SMALL, PUZZLING COMET [J].
HANNER, MS ;
NEWBURN, RL ;
SPINRAD, H ;
VEEDER, GJ .
ASTRONOMICAL JOURNAL, 1987, 94 (04) :1081-1087
[9]   Spectrophotometry and the development of emissions for C/1996 B2 (Comet Hyakutake) [J].
Hicks, MD ;
Fink, U .
ICARUS, 1997, 127 (02) :307-318
[10]  
HODGES RR, 1990, ICARUS, V83, P410, DOI 10.1016/0019-1035(90)90076-L