|
|||||
|
|
Visible and near-infrared spectrophotometry of the Deep Impact ejecta of Comet 9P/Tempel 1 |
|
| Authors: | Klaus W Hodapp Greg Aldering Anita L Cochran Emmanuel Pécontal Nathalie Blanc David K Lynch S Mazuk Richard C Puetter |
| Institution: | a Institute for Astronomy, University of Hawaii, 640 N. Aohoku Place, Hilo, HI 96720, USA b Lawrence Berkeley Lab, Physics Div., MS-50/232, One Cyclotron Rd., Berkeley, CA 94720, USA c Institute for Astronomy, University of Hawaii, and NASA Astrobiology Institute, 2680 Woodlawn Drive, Honolulu, HI 96822, USA d McDonald Observatory, University of Texas at Austin, 1 University Station C1402, Austin, TX 78712-0259, USA e The Aerospace Corporation, P.O. Box 92957, MS 266, Los Angeles, CA 90009, USA f University of California, San Diego, CASS 0424, 9500 Gilman Dr., La Jolla, San Diego, CA 92093, USA g NASA Langley Research Center, MS 160, Science Support Office, Hampton, VA 23681, USA h Laboratoire de Physique Nucléaire et des Hautes Energies, IN2P3 - CNRS, Universités Paris VI et Paris VII, 4 Place Jussieu Tour 33 - Rez des chaussée, 75252 Paris Cedex 05, France i Centre de Recherche Astronomique de Lyon, 9, av. Charles André, 69561 Saint Genis Laval Cedex, France j Institut de Physique Nucleéaire de Lyon, UMR5822, CNRS-IN2P3, Université Claude Bernard Lyon 1, F-69622 Villeurbanne, France |
| Abstract: | We have obtained optical spectrophotometry of the evolution of Comet 9P/Tempel 1 after the impact of the Deep Impact probe, using the Supernova Integral Field Spectrograph (SNIFS) at the UH 2.2-m telescope, as well as simultaneous optical and infrared spectra using the Lick Visible-to-Near-Infrared Imaging Spectrograph (VNIRIS). The spatial distribution and temporal evolution of the “violet band” CN (0-0) emission and of the 630 nm OI] emission was studied. We found that CN emission centered on the nucleus increased in the 2 h after impact, but that this CN emission was delayed compared to the light curve of dust-scattered sunlight. The CN emission also expanded faster than the cloud of scattering dust. The emission of OI] at 630 nm rose similarly to the scattered light, but then remained nearly constant for several hours after impact. On the day following the impact, both CN and OI] emission concentrated on the comet nucleus had returned nearly to pre-impact levels. We have also searched for differences in the scattering properties of the dust ejected by the impact compared to the dust released under normal conditions. Compared to the pre-impact state of the comet, we find evidence that the color of the comet was slightly bluer during the post-impact rise in brightness. Long after the impact, in the following nights, the comet colors returned to their pre-impact values. This can be explained by postulating a change to a smaller particle size distribution in the ejecta cloud, in agreement with the findings from mid-infrared observations, or by postulating a large fraction of clean ice particles, or by a combination of these two. |
| Keywords: | Comets Comet Tempel 1 Photometry Spectroscopy |
| 本文献已被 ScienceDirect 等数据库收录！ | |