论文标题
深影响：在MIRA获得的光谱和光度法
Deep Impact: Optical Spectroscopy and Photometry Obtained at MIRA
论文作者
论文摘要
我们提出光谱和高精度光度观测值，跨越光学紫外线到2005年7月4日的NASA深撞击事件之前，期间和之后。脑昏迷的内部2000 km的内部2000 km约为0.3幅度的B-R中的红色大约比外昏迷。前破裂的光谱是一种微弱的反射太阳光谱，该光谱由分子排放量延伸到距核> 40000 km。 R和R中的影响后的光曲线显示出在撞击后的最初18分钟内与光学厚云的迅速上升。在接下来的8分钟内，云变得光学薄。撞击后60分钟，冲击R-band通量在7.5 x 10-15 erg cm-2 s-1Å-1处达到高原，彗星在15英寸的孔径中观察到的彗星亮度高出〜4.3。在15英寸的孔径中观察到的前IMPACT价值。在第一个49分钟内，频率的平均膨胀速度是229 {\ pm pm pm pm pm pm} 49 m-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-1。体积散射功能（VSF）在撞击后32分钟显示出强烈的红色。在撞击之后的夜晚，彗星仍然比撞击之前更明亮，但是撞击的效果恢复了，在撞击后25个小时。
We present spectroscopic and high-precision photometric observations, spanning the optical UV to the far red, before, during, and after the NASA Deep Impact event of July 4, 2005. The inner 2000 km of the pre and post-impact coma was about 0.3 magnitude redder in B-R than in the outer coma. The pre-impact spectrum was a faint reflected solar spectrum dominated by molecular emissions extending > 40000 km from the nucleus. The post-impact light curve in R and I showed a rapid rise consistent with an expanding optically thick cloud during the first 18 minutes after impact. During the next 8 minutes the cloud became optically thin. Sixty minutes after impact the impact R-band flux reached a plateau at 7.5 x 10-15 erg cm-2 s-1 Å-1, the comet brightening by a factor of ~4.3 above its pre-impact value observed in a 15" aperture. The mean expansion velocity of the grains during the first 49 minutes was 229 {\pm} 49 m s-1. The spectrum became dominated by scattered sunlight during the first hour after impact. The volume scattering function (VSF) observed 32 minutes after impact shows strong reddening. At 49 minutes, however, the VSF shows an additional two-fold increase in the blue but only a 20 per-cent increase at 5500Å. Post-impact spectra and R-I photometry showed rapid reddening. The particle size distribution, dominated by 1 to 2.5 micron particles shortly after impact, changed dramatically during the first hour due to sublimation of water-ice particles of this size. On the night following impact the comet was still substantially brighter than before impact, but R-I had returned to its pre-impact value. B-R remained significantly redder. The ejecta 25 hours after impact was fan-shaped subtending ~180° roughly symmetrical about position angle 225°. The mean expansion velocity 90° from the direction to the Sun was 185° 12 m s-1.
