被扭曲的星系英文原文
译:Jack


    NASA的哈勃太空望远镜最近拍摄到了一个星系的照片。张照片向我们揭示了扭曲了的星系盘,我们从中也可以知道星系冲撞中,星系是如何产生下一代的恒星的。

    一般说来,星系的尘带和旋臂在星系的侧面看来是平直的——例如我们的银河系。这次哈勃拍摄的是ESO 510-G13,这个星系的边缘十分的奇特,因为它已经被扭曲了。在智利的欧南台,我们利用地基望远镜第一次看见了这个星系。这个星系——也就是ESO 510-G13,处于南天的长蛇座,距离我们1亿5千万光年。

        image29.jpg (23453 字节)

    我们可以看见这个星系的精细的结构,因为这个标示这个星系星系盘的尘埃云被这个星系中央的星系核照亮了。

    这个星系的星系盘强烈的扭曲了,这表明,这个星系在不久之前曾经和邻近的星系有过冲撞,而且,这个星系正在吞没邻近的星系。在过去的几千万年中,这个星系的结构被引力弄得乱七八糟,当然这两个星系的恒星气体和尘埃也已经混杂在一块了。这样,这两个星系间的征战便渐渐的结束了,ESO 510-G13看起来,也像是一个单独的星系了。

    我们在ESO 510-G13的外部,特别是图片的右边——我们可以看见,星系的那被扭曲的星系盘中,不仅仅有尘带,更有一些明亮的、蓝色的恒星组成的恒星区。这表明,恒星正在星系盘中形成。天文学家们相信,这些恒星的产生是星系冲撞引发的,因为,在星系的冲撞中,星际云被撕碎了,然后,在引力的作用下,这些星际云重新结合了。

    哈勃Heritage小组利用宽视场行星望远镜(WFPC2)拍摄了这个星系——ESO 510-G13。为了突出星系中心的核球、星系的旋臂和恒星形成区,他们采用了蓝色、红色和绿色的滤镜。就这样,哈勃在观测ESO 510-G13时,变为它自己树下了一个里程碑:哈勃太空望远镜自1993年升空以来,已经拍摄了100,000张照片了。

图片拥有者: NASA and The Hubble Heritage Team (STScI/AURA)
知识产权: C. Conselice (U. Wisconsin/STScI)


快速事实
有关这个天体
名称:ESO 510-G13
天体类型:漩涡星系
位置(2000):赤经:13h 55m 04.8s
赤纬:-26°46' 48.0"
星座:长蛇座
距离:46兆秒差距(1.5亿光年)
范围:这张图片展示的是2.4弧分宽(32000千秒差距,105,000光年)的ESO 510-G13

仪器: FOC NICMOS WFPC2
曝光日期:1993年7月18日,1998年7月29日, 1999年3月5日
滤镜: F450W (B)
F555W (V)
F675W (R)
曝光日期:2001年4月6~7日,
总计曝光时间:3.3小时


负责人:K. Noll
H. Bond
C. ChristianS. Crawshaw
L. Frattare
F. Hamilton
J. Lee
Z. Levay
T. Royle (Hubble Heritage Team/STScI)
C. Conselice (U. Wisconsin/STScI)
图片提供日期:美国东部时间2001年8月2日,上午9点

 

   译自 哈勃网站(http://oposite.stsci.edu

Hubble Photographs Warped Galaxy as Camera Passes Milestonee
Chinese Version


  NASA's Hubble Space Telescope has captured an image of an unusual edge-on galaxy, revealing remarkable details of its warped dusty disk and showing how colliding galaxies spawn the formation of new generations of stars.

  The dust and spiral arms of normal spiral galaxies, like our own Milky Way, appear flat when viewed edge-on. This month's Hubble Heritage image of ESO 510-G13 shows a galaxy that, by contrast, has an unusual twisted disk structure, first seen in ground-based photographs obtained at the European Southern Observatory (ESO) in Chile. ESO 510-G13 lies in the southern constellation Hydra, roughly 150 million light-years from Earth.

  Details of the structure of ESO 510-G13 are visible because the interstellar dust clouds that trace its disk are silhouetted from behind by light from the galaxy's bright, smooth central bulge.

  The strong warping of the disk indicates that ESO 510-G13 has recently undergone a collision with a nearby galaxy and is in the process of swallowing it. Gravitational forces distort the structures of the galaxies as their stars, gas, and dust merge together in a process that takes millions of years. Eventually the disturbances will die out, and ESO 510-G13 will become a normal-appearing single galaxy.

  In the outer regions of ESO 510-G13, especially on the right-hand side of the image, we see that the twisted disk contains not only dark dust, but also bright clouds of blue stars. This shows that hot, young stars are being formed in the disk. Astronomers believe that the formation of new stars may be triggered by collisions between galaxies, as their interstellar clouds smash together and are compressed.

  The Heritage Team used Hubble's Wide Field Planetary Camera 2 (WFPC2) to observe ESO 510-G13 in April 2001. Pictures obtained through blue, green, and red filters were combined to make this color-composite image, which emphasizes the contrast between the dusty spiral arms, the bright bulge, and the blue star-forming regions. During the observations of ESO 510-G13, WFPC2 passed the milestone of taking its 100,000th image since its installation in the telescope by shuttle astronauts in 1993.

Image Credit: NASA and The Hubble Heritage Team (STScI/AURA)
Acknowledgment: C. Conselice (U. Wisconsin/STScI)



About this Object Name: ESO 510-G13
Object Description: Edge-on Spiral Galaxy
Position (J2000): R.A. 13h 55m 04.8s
Dec. -26° 46' 48.0''
Constellation: Hydra
Distance: 46 Mpc (150 million light-years)
Dimensions: This image is 2.4 arcminutes wide, or roughly 32 kpc (105,000 light-years) at the distance of ESO 510-G13.


About the Data Instrument: WFPC2
Filters: F450W (B); F555W (V); F675W (R)
Exposure Dates: April 6-7, 2001
Total Exposure Time: 3.3 hours
Principal Astronomers: K. Noll, H. Bond, C. Christian, S. Crawshaw, L. Frattare, F. Hamilton, J. Lee, Z. Levay, T. Royle (Hubble Heritage Team/STScI) and C. Conselice (U. Wisconsin/STScI)


About this Image Image Credit: NASA and The Hubble Heritage Team (STScI/AURA)
Release Date: August 2, 2001 9:00 a.m. (EDT)

 

   From Hubble Web(http://oposite.stsci.edu

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