美国国家航空航天局及国际太空望远镜观测到新生恒星的喷流

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用不同颜色显示恒星喷流的天文图片 (NASA/JPL-Caltech/ALMA)

这是一颗新生恒星!通过“史匹哲太空望远镜”(Spitzer Space Telescope)和刚刚在智利组建完成的“阿塔卡玛大型毫米及次毫米波阵列”(Atacama Large Millimeter/submillimeter Array, ALMA)进行的联合观测史无前例地展现了已得到大量研究的名为HH46/47的天体中恒星诞生时的强烈喷流。

赫比格-哈罗(Herbig-Haro,HH)天体是在新生恒星喷射出的喷流与周围物质碰撞产生微小、明亮、星云状的区域时形成的。许多赫比格-哈罗天体被气体和尘埃所笼罩,遮蔽了天体内部的动态活动。但是“史匹哲”和“阿塔卡玛大型毫米及次毫米波阵列”分别观测到的光线的红外光和次毫米波长穿透了HH46/47周围黑暗的宇宙云。

“史匹哲”的观测显示出一对超音速喷流,从中心恒星喷射而出,冲击周围气体并激发它们发光,形成两个喷流勃发的波瓣。HH46/47恰好位于笼罩着它们的星云边缘,其位置可以使喷流穿过两个不同的宇宙环境。右向喷流冲入星云,艰难地穿过一层物质“墙”,而左向喷流在冲出星云的路径上所穿过的物质较少,相对没有什么障碍。这种格局对科学家很有帮助,便于他们比较和对比正在形成的恒星喷射出的喷流如何与周围环境相互作用。

位于康涅狄格州纽黑文市(New Haven,Connecticut)的耶鲁大学(Yale University)的埃克托尔·阿尔塞(Hector Arce)带领的一个团队进行了“阿塔卡玛大型毫米及次毫米波阵列”观测,他们的分析结果于最近发表在《天体物理学刊》(The Astrophysical Journal)上。“阿塔卡玛大型毫米及次毫米波阵列”是欧洲、北美和东亚与智利的一个伙伴合作项目。



Read more:http://iipdigital.usembassy.gov/st/chinese/inbrief/2013/11/20131120287188.html#ixzz2lL4y0SZU

NASA and International Telescopes Reveal Star’s Bubbly Birth

Astronomical image showing jets of stellar material in representative colors (NASA/JPL-Caltech/ALMA)

It’s a baby star! Combined observations from NASA’s Spitzer Space Telescope and the newly completed Atacama Large Millimeter/submillimeter Array (ALMA) in Chile have revealed the throes of stellar birth as never before in the well-studied object known as HH 46/47.

Herbig-Haro (HH) objects form when jets shot out by newborn stars collide with surrounding material, producing small, bright, nebulous regions. The dynamics within many HH objects are obscured by enveloping gas and dust. But the infrared and submillimeter wavelengths of light seen by Spitzer and ALMA, respectively, pierce the dark cosmic cloud around HH 46/47.

The Spitzer observations show twin supersonic jets emanating from the central star that blast away surrounding gas and set it alight into two bubbly lobes. HH 46/47 happens to sit on the edge of its enveloping cloud in such a way that the jets pass through two differing cosmic environments. The rightward jet, heading into the cloud, is plowing through a “wall” of material, while the leftward jet’s path out of the cloud is relatively unobstructed, passing through less material. This orientation serves scientists well by offering a handy compare-and-contrast setup for how the outflows from a developing star interact with their surroundings.

A team led by Hector Arce at Yale University in New Haven, Connecticut, carried out the ALMA observations, and their analysis was published recently in The Astrophysical Journal. ALMA is a partnership of Europe, North America and East Asia in cooperation with Chile.



Read more:http://iipdigital.usembassy.gov/st/english/inbrief/2013/11/20131115286920.html#ixzz2lL4zPmYU

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