太陽の10万倍

Ian Sample “Massive black hole discovered near heart of the Milky Wayhttps://www.theguardian.com/science/2017/sep/04/supermassive-black-hole-discovered-near-heart-of-the-milky-way


慶應義塾大学の岡朋治氏*1のグループが天の川の中心部附近に「太陽よりも10万倍重いブラック・ホール*2」を発見したという報道;


An enormous black hole one hundred thousand times more massive than the sun has been found hiding in a toxic gas cloud wafting around near the heart of the Milky Way.

If the discovery is confirmed, the invisible behemoth will rank as the second largest black hole ever seen in the Milky Way after the supermassive black hole known as Sagittarius A* that is anchored at the very centre of the galaxy.

Astronomers in Japan found evidence for the new object when they turned a powerful telescope in the Atacama desert in Chile towards the gas cloud in the hope of understanding the strange movement of its gases. Unlike those that make up other interstellar clouds, the gases in this cloud – including hydrogen cyanide and carbon monoxide – move at wildly different speeds.

Observations from the Alma telescope in Chile showed that molecules in the elliptical cloud, which is 200 light years from the centre of the Milky Way and 150 trillion kilometres wide, were being pulled around by immense gravitational forces. The most likely cause, according to computer models, was a black hole no more than 1.4 trillion km across.

The scientists’ suspicion that a black hole lay in the midst of the gas cloud received a boost when further observations picked up radio waves indicative of a black hole coming from the centre of the cloud, said Tomoharu Oka, an astronomer at Keio University in Tokyo. “This is the first detection of an intermediate-mass black hole candidate in the Milky Way galaxy,” he said.

論文は、


Tomoharu Oka, Shiho Tsujimoto, Yuhei Iwata, Mariko Nomura & Shunya Takekawa “Millimetre-wave emission from an intermediate-mass black hole candidate in the Milky Wayhttps://www.nature.com/articles/s41550-017-0224-z


See also


国立天文台野辺山宇宙電波観測所「天の川銀河の中で二番目に大きなブラックホールの兆候を発見」http://www.nro.nao.ac.jp/news/2016/0115-oka.html
“Japanese Astronomers Detect Signs of Milky Way’s Second-Largest Black Hole” http://www.sci-news.com/astronomy/milky-ways-second-largest-black-hole-03571.html


これらは昨年1月の記事。基本的には同じ現象のことだと思うのだが、今回は「兆候(signs)」から確証の度合いがさらに上がったということなのだろうか。