武山さん

 

誤字の修正は即刻行います。

 

ブラックホールは、質量の大きく年をとった星が爆発を起こしたときに出来るので、銀河の中心でなくても出来るため、銀河中にはいくつものブラックホールがあるでしょう。

 

一方、多くの銀河の中心には巨大なブラックホールがあると考えられています。以下は、数件の文献です。

 

〔1〕http://www.nasa.gov/worldbook/galaxy_worldbook.html

The cause of the intense activity in active galaxies is thought to arise from a colossal black hole at the galactic center. The black hole can be as much as a billion times as massive as the sun. Because the black hole is so massive and compact, its gravitational force is powerful enough to tear apart nearby stars. The resulting dust and gas fall toward the black hole, adding their mass to a disk of matter called an accretion disk that orbits the black hole. At the same time, matter from the inner edge of the disk falls into the black ho

 

 

〔2〕http://en.wikipedia.org/wiki/Milky_way

The galactic center harbors a compact object of very large mass as determined by the motion of material around the center.[23] The intense radio source named Sagittarius A*, thought to mark the center of the Milky Way, is newly confirmed to be a supermassive black hole. For a photo see Chandra X-ray Observatory; Jan. 6, 2003 Most galaxies are believed to have a supermassive black hole at their center.[24]le. As the matter falls, it loses

ergy, thereby producing the radiation and jets that shoot out of the galaxy

 

〔3〕http://en.wikipedia.org/wiki/Galaxy

Although it is not yet well understood, dark matter appears to account for around 90% of the mass of most galaxies. Observational data suggests that supermassive black holes may exist at the center of many, if not all, galaxies. They are proposed to be the primary cause of active galactic nuclei found at the core of some galaxies. The Milky Way galaxy appears to harbor at least one such object within its nucleus.[10]

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