NGC 7822：宇宙问号
(原标题: NGC 7822: Cosmic Question Mark)
2021-10-13
浏览次数: 36
它可能看起来像一个巨大的宇宙问号，但真正的大问题是，明亮的气体和黑暗的尘埃如何告诉这个星云恒星形成的历史。在靠近北方仙王座的巨大分子云的边缘，发光的恒星形成区NGC 7822距离我们大约3000光年。在星云内部，明亮的边缘和黑暗的形状在这张色彩斑斓、细节丰富的天空景观中显得尤为突出。这幅由9个面板组成的马赛克图是用德克萨斯州的一台小型望远镜在28个晚上拍摄的，其中包括来自窄带滤光片的数据，将原子氧、氢和硫的发射映射成蓝色、绿色和红色。发射线和颜色的组合已经成为众所周知的哈勃调色板。原子发射是由中心热恒星的高能辐射提供动力的。它们强大的风和辐射塑造并侵蚀了密度更大的柱状结构，并在星云中心形成了一个横跨数光年的特征空洞。恒星仍可能在引力坍缩的作用下在柱体内部形成，但随着柱体被侵蚀，任何正在形成的恒星最终都将与恒星物质的储存库隔绝。这张视场跨度超过40光年，估计距离NGC 7822。
查看原文解释
It may look like a huge cosmic question mark, but the big question really is how does the bright gas and dark dust tell this nebula's history of star formation. At the edge of a giant molecular cloud toward the northern constellation Cepheus, the glowing star forming region NGC 7822 lies about 3,000 light-years away. Within the nebula, bright edges and dark shapes stand out in this colorful and detailed skyscape. The 9-panel mosaic, taken over 28 nights with a small telescope in Texas, includes data from narrowband filters, mapping emission from atomic oxygen, hydrogen, and sulfur into blue, green, and red hues. The emission line and color combination has become well-known as the Hubble palette. The atomic emission is powered by energetic radiation from the central hot stars. Their powerful winds and radiation sculpt and erode the denser pillar shapes and clear out a characteristic cavity light-years across the center of the natal cloud. Stars could still be forming inside the pillars by gravitational collapse but as the pillars are eroded away, any forming stars will ultimately be cut off from their reservoir of star stuff. This field of view spans over 40 light-years across at the estimated distance of NGC 7822.
© Yizhou Zhang