Space.com
Astronomers from MIT and other institutions have found that periodic eruptions from a supermassive black hole located in a galaxy about 800 million light-years from Earth could be caused by a, “second, smaller black hole slamming into a disk of gas and dust, or ‘accretion disk,’ surrounding the supermassive black hole, causing it to repeatedly ‘hiccup’ out matter,” writes Rob Lea for Space.com.