TY - JOUR
T1 - High-dispersion spectra of NH2 in the comet C/1999 S4 (LINEAR)
T2 - Excitation mechanism of the NH2 molecule
AU - Kawakita, Hideyo
AU - Watanabe, Jun Ichi
AU - Kinoshita, Daisuke
AU - Abe, Shinsuke
AU - Furusho, Reiko
AU - Izumiura, Hideyuki
AU - Yanagisawa, Kenshi
AU - Masuda, Seiji
PY - 2001
Y1 - 2001
N2 - We carried out a high-dispersion spectroscopic observation of the comet C/1999 S4 (LINEAR) on 2000 July 8.75 (UT). The NH2 Ã(0, 10, 0)-X̃(0, 0, 0) and Ã(0, 9, 0)-X̃(0, 0, 0) bands were extracted from the observed spectrum and compared with the modeled spectra. We developed a fluorescence equilibrium model for the NH2, in which Ã(0, v′2, 0)-X̃(0, 0, 0) transitions and the radiative relaxation among the rotational levels in X̃(0, 0, 0) were considered. The rotational structure of the spin doublet (F1 and F2 levels) and the Swings effect were considered in the model. The modeled spectra are consistent with the observed spectra of the Ã(0, 10, 0) and Ã(0, 9, 0) bands. Our results show that the fluorescence excitation and the radiative relaxation processes are dominant for NH2 in a coma of the comet at ∼ 1 AU from the Sun.
AB - We carried out a high-dispersion spectroscopic observation of the comet C/1999 S4 (LINEAR) on 2000 July 8.75 (UT). The NH2 Ã(0, 10, 0)-X̃(0, 0, 0) and Ã(0, 9, 0)-X̃(0, 0, 0) bands were extracted from the observed spectrum and compared with the modeled spectra. We developed a fluorescence equilibrium model for the NH2, in which Ã(0, v′2, 0)-X̃(0, 0, 0) transitions and the radiative relaxation among the rotational levels in X̃(0, 0, 0) were considered. The rotational structure of the spin doublet (F1 and F2 levels) and the Swings effect were considered in the model. The modeled spectra are consistent with the observed spectra of the Ã(0, 10, 0) and Ã(0, 9, 0) bands. Our results show that the fluorescence excitation and the radiative relaxation processes are dominant for NH2 in a coma of the comet at ∼ 1 AU from the Sun.
KW - Comets: general
KW - Comets: individual (C/1999 S4: LINEAR)
KW - Molecular processes
UR - http://www.scopus.com/inward/record.url?scp=0039893844&partnerID=8YFLogxK
U2 - 10.1093/pasj/53.1.l5
DO - 10.1093/pasj/53.1.l5
M3 - 期刊論文
AN - SCOPUS:0039893844
SN - 0004-6264
VL - 53
SP - L5-L8
JO - Publications of the Astronomical Society of Japan
JF - Publications of the Astronomical Society of Japan
IS - 1
ER -