SS 433：双星系统形成的微类星体
2020年8月31日
SS 433: Binary Star Micro-Quasar
Animation Credit: DESY, Science Communication Lab
Explanation: SS 433 is one of the most exotic star systems known. Its unremarkable name stems from its inclusion in a catalog of Milky Way stars which emit radiation characteristic of atomic hydrogen. Its remarkable behavior stems from a compact object, a black hole or neutron star, which has produced an accretion disk with jets. Because the disk and jets from SS 433 resemble those surrounding supermassive black holes in the centers of distant galaxies, SS 433 is considered a micro-quasar. As illustrated in the animated featured video based on observational data, a massive, hot, normal star is locked in orbit with the compact object. As the video starts, material is shown being gravitationally ripped from the normal star and falling onto an accretion disk. The central star also blasts out jets of ionized gas in opposite directions – each at about 1/4 the speed of light. The video then pans out to show a top view of the precessing jets producing an expanding spiral. From even greater distances, the dissipating jets are then visualized near the heart of supernova remnant W50. Two years ago, SS 433 was unexpectedly found by the HAWC detector array in Mexico to emit unusually high energy (TeV-range) gamma-rays. Surprises continue, as a recent analysis of archival data taken by NASA’s Fermi satellite find a gamma-ray source — separated from the central stars as shown — that pulses in gamma-rays with a period of 162 days – the same as SS 433’s jet precession period – for reasons yet unknown.
Teachers & Students: Ideas for utilizing APOD in the classroom.
Tomorrow’s picture: salted asteroid
SS 433：双星系统形成的微类星体
动画提供: DESY, Science Communication Lab
说明: SS 433是现知最怪异的恒星系统。它听来并不出采的名号，源自一个编录会发出原子氢特征辐射的银河系恒星之星表。而它奇特的行为，则来自致密天体（黑洞或中子星）所造就的吸积盘和喷流。由于SS 433的吸积盘和喷流，神似遥远星系核心超大质量黑洞的类似结构，故SS 433被归类为微类星体。如这部根据观测数据建构的主题动画所示，在这个系统里，一颗大质量的炽热正常恒星被锁定绕行中心的致密天体。在动画开始时，正常恒星的物质受到重力剥离掉入吸积盘。中心的恒星同时也从相反的二侧，以1/4光速射出由电离气体组成的喷流。接着影像镜头拉远，从顶端俯视进动的喷流及它产生的扩张螺旋。镜头拉得更远之后，可见到逐渐消散的喷流座落在超新星遗迹 W50的中心附近。2年多前，墨西哥的HAWC侦测器阵列，意外发现SS 433会辐射出能量高达TeV的伽玛射线。其他的意外行为接踵而至，包括最近分析美国航太总署．费米天文卫星的库存数据，更发现一个未与中心恒星重合的伽玛射线源，而且发出复现周期为162天的伽玛射线脉冲；这个射线源的周期和SS 433喷流的进动周期相同，不过目前其原因仍不明。
教师和学生：在课堂上使用APOD的创意。
明日的图片: salted asteroid