探索發現:科學家發現天文史上驚現最年輕黑洞

　
Astronomers using NASA's Chandra X-ray Observatory have found evidence of the youngest black hole known to exist in our cosmic neighborhood. The 30-year-old black hole provides a unique opportunity to watch this type of object develop from infancy. 　　
　
天文學家們用錢拉德用 x射線觀測儀探測到了最年輕黑洞的蛛絲馬跡*，它位於我們臨近的星系裏。這個僅30歲的年輕黑洞爲科學家研究黑洞成長提供了得天獨厚的條件。

The black hole could help scientists better understand how massive stars explode, which ones leave behind black holes or neutron stars, and the number of black holes in our galaxy and others.

該黑洞能幫助科學家解惑：大型恆星爆炸以後，它的產物到底是黑洞還是中子星；以及我們或其他銀河系裏到底有多少黑洞。

The 30-year-old object is a remnant of SN 1979C, a supernova in the galaxy M100 approximately 50 million light years from Earth. Data from Chandra, NASA's Swift satellite, the European Space Agency's XMM-Newton and the German ROSAT observatory revealed a bright source of X-rays that has remained steady during observation from 1995 to 2007. This suggests the object is a black hole being fed either by material falling into it from the supernova or a binary companion.

這個30歲的物體*是SN 1979C 超新星爆炸以後的遺留物，它位於M100星系，距地球大約500萬光年。NASA錢拉德和雨燕衛星*，歐洲天文中心的XMM-牛頓*以及德國的倫琴衛星*的觀測，揭露出該物體自1995年到2007年間，持續發出強x射線。這顯示該物體很可能是一個黑洞，正吸收超新星或是雙子伴星上的物質。

"If our interpretation is correct, this is the nearest example where the birth of a black hole has been observed," said Daniel Patnaude of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. who led the study.

“如果我們的推斷正確的話，這將是迄今爲止觀測到的距離地球最近的新生黑洞”。馬薩諸薩州劍橋哈佛-史密森天體物理中心的該項目的領頭人Daniel Patnaude表示。

The scientists think SN 1979C, first discovered by an amateur astronomer in 1979, formed when a star about 20 times more massive than the sun collapsed. Many new black holes in the distant universe previously have been detected in the form of gamma-ray bursts (GRBs). However, SN 1979C is different because it is much closer and belongs to a class of supernovas unlikely to be associated with a GRB. Theory predicts most black holes in the universe should form when the core of a star collapses and a GRB is not produced.

SN 1979C是由一位業餘天文愛好着於1979年首次發現，科學家認爲它是由一顆質量比太陽大20倍的恆星坍塌後形成的。歷史上也有很多宇宙深處的年輕黑洞因爲伽馬線暴（GRBs）而被發現。 但是SN 1979C獨一無二的是它離我們非常近，而且本該歸屬於超新星範圍，不應該產生伽馬線暴。 理論上，黑洞大多由恆星核坍塌以後形成，應該不會產生伽馬線暴。

"This may be the first time the common way of making a black hole has been observed," said co-author Abraham Loeb, also of the Harvard-Smithsonian Center for Astrophysics. "However, it is very difficult to detect this type of black hole birth because decades of X-ray observations are needed to make the case."

“這大概是有史以來第一次發現一般黑洞的形成。”哈佛-史密森中心的合作研究者Abraham Loeb表示，“但是我們很難探測到這類黑洞的產生，至少要經過多年的x光觀測才能產生定論。”

The idea of a black hole with an observed age of only about 30 years is consistent with recent theoretical work. In 2005, a theory was presented that the bright optical light of this supernova was powered by a jet from a black hole that was unable to penetrate the hydrogen envelope of the star to form a GRB. The results seen in the observations of SN 1979C fit this theory very well.

該新發現的黑洞只有30年曆史與符合最新理論。在2005年，超新星的耀眼光芒來自於黑洞的噴射流，該黑洞噴射流不能穿透恆星的氫氣包裹層形成伽馬射線暴。 該觀點在 SN 1979C身上得到了充分證明。

Although the evidence points to a newly formed black hole in SN 1979C, another intriguing possibility is that a young, rapidly spinning neutron star with a powerful wind of high energy particles could be responsible for the X-ray emission. This would make the object in SN 1979C the youngest and brightest example of such a "pulsar wind nebula" and the youngest known neutron star. The Crab pulsar, the best-known example of a bright pulsar wind nebula, is about 950 years old.

雖然證據顯示SN 1979C 形成的是一個新興黑洞，另外一個有趣的假設認爲，它可能是一個年輕的，快速旋轉的中子星，強大的波雲風拋射出高能量粒子也可能產生強x射線。該假設總結出SN 1979C 中的物體爲最年輕和最明亮的“脈衝波霎星雲”和已知最年輕的中子星。蟹狀星雲是最爲人所知的脈衝波霎星雲，目前已有950歲了。

"It's very rewarding to see how the commitment of some of the most advanced telescopes in space, like Chandra, can help complete the story," said Jon Morse, head of the Astrophysics Division at NASA's Science Mission Directorate.

“錢拉德等非常先機的觀測儀功不可沒，是它們幫助我們完成了神話。” NASA任務指揮戰的天文部長Jon Morse提起那些衛星的功勞就讚歎不已。