美国国家航空航天局NASA每日一图-2017年6月23日

Hubble Uses Gravitational Lens to Capture Disk Galaxy

Acting as a “natural telescope” in space, the gravity of the extremely massive foreground galaxy cluster MACS J2129-0741 magnifies, brightens, and distorts the far-distant background galaxy MACS2129-1 in the upper-right corner of this image. (View an annotated image highlighting the gravitationally-lensed galaxy.)

By combining the power of this "natural lens" in space with the capability of NASA's Hubble Space Telescope, astronomers made a surprising discovery—the first example of a compact yet massive, fast-spinning, disk-shaped galaxy that stopped making stars only a few billion years after the big bang.  Finding such a galaxy early in the history of the universe challenges the current understanding of how massive galaxies form and evolve, say researchers. This is the first direct observational evidence that at least some of the earliest so-called "dead" galaxies — where star formation stopped — somehow evolve from a Milky Way-shaped disk into the giant elliptical galaxies we see today.

Read more: Hubble Captures Massive Dead Disk Galaxy that Challenges Theories of Galaxy Evolution

Image Credit: NASA, ESA, M. Postman (STScI), and the CLASH team

Last Updated: June 23, 2017
Editor: Sarah Loff

哈勃采用重力镜头捕获磁盘银河

作为太空中的“天然望远镜”,极度巨大的前景星系团集MACS J2129-0741的重力将放大,增亮和扭曲该图像右上角远处的背景星系MACS2129-1。 (查看突出显示重力透镜星系的注释图像。)

天文学家将空间中的这种“天然镜头”的力量与NASA的哈勃太空望远镜的能力相结合,令人惊奇的发现 - 这是一个紧凑而又大规模,快速旋转的盘形星系的第一个例子,大爆炸几十年后。研究人员说,在宇宙历史早期找到这样一个星系,挑战了目前对于大规模星系形成和演化的认识。这是第一个直接观察证据,至少有一些最早所谓的“死亡”星系 - 星星形成停止 - 以某种方式从银河系的磁盘演变成我们今天看到的巨型椭圆星系。

阅读更多:哈勃捕获大规模死磁盘银河,挑战银河演化的理论

图片来源:NASA,ESA,邮政(STScI)和CLASH团队

最后更新:2017年6月23日
编辑:莎拉·洛夫

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