Krause Oliver, Rieke George H, Birkmann Stephan M, Le Floc'h Emeric, Gordon Karl D, Egami Eiichi, Bieging John, Hughes John P, Young Erick T, Hinz Joannah L, Quanz Sascha P, Hines Dean C
Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721, USA.
Science. 2005 Jun 10;308(5728):1604-6. doi: 10.1126/science.1112035.
Two images of Cassiopeia A obtained at 24 micrometers with the Spitzer Space Telescope over a 1-year time interval show moving structures outside the shell of the supernova remnant to a distance of more than 20 arc minutes. Individual features exhibit apparent motions of 10 to 20 arc seconds per year, independently confirmed by near-infrared observations. The observed tangential velocities are at roughly the speed of light. It is likely that the moving structures are infrared echoes, in which interstellar dust is heated by the explosion and by flares from the compact object near the center of the remnant.
利用斯皮策空间望远镜在24微米波长下于1年时间间隔内获取的仙后座A的两张图像显示，在超新星遗迹外壳之外存在移动结构，延伸至超过20角分的距离。各个特征每年表现出10至20角秒的视运动，这一结果得到了近红外观测的独立证实。观测到的切向速度大致为光速。这些移动结构很可能是红外回波，其中星际尘埃因爆炸以及遗迹中心附近致密天体的耀斑而被加热。
