Water in Comet C/2003 K4 (LINEAR) with Spitzer - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue The Astrophysical Journal Année : 2007

Water in Comet C/2003 K4 (LINEAR) with Spitzer

Résumé

We present sensitive 5.5-7.6 mum spectra of comet C/2003 K4 (LINEAR) obtained on 2004 July 16 (rh=1.760 AU, DeltaSpitzer=1.409 AU, phase angle=35.4deg) with the Spitzer Space Telescope. The nu2 vibrational band of water is detected with a high signal-to-noise ratio (>~50). Model fitting to the best spectrum yields a water ortho-to-para ratio of 2.47+/-0.27, which corresponds to a spin temperature of 28.5+6.5-3.5 K. Spectra acquired at different offset positions show that the rotational temperature decreases with increasing distance from the nucleus, which is consistent with evolution from thermal to fluorescence equilibrium. The inferred water production rate is (2.43+/-0.25)×1029 molecules s-1. The spectra do not show any evidence for emission from PAHs and carbonate minerals, in contrast to results reported for comets 9P/Tempel 1 and C/1995 O1 (Hale-Bopp). However, residual emission is observed near 7.3 mum, the origin of which remains unidentified.
Fichier non déposé

Dates et versions

hal-03786523 , version 1 (23-09-2022)

Identifiants

Citer

Charles E. Woodward, Michael S. Kelley, Dominique Bockelée-Morvan, R. D. Gehrz. Water in Comet C/2003 K4 (LINEAR) with Spitzer. The Astrophysical Journal, 2007, 671, pp.1065-1074. ⟨10.1086/522366⟩. ⟨hal-03786523⟩
3 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More