Small Black Holes Are Deadlier Than Previously Thought
There’s a black hole in a galaxy 22 million light-years away that’s incredibly bright and energetic. Astronomers naturally assumed it was a supermassive black hole. But new observations show it’s actually quite tiny — throwing many conceptions of what we thought we knew about these things completely out the window.
Black holes come in two types, possibly three. Or four. We’ve got our supermassive black hole variety, the kind you might find at a galaxy’s core. As its name would suggest, these things are absolutely huge, weighing in at about a billion times the mass of our Sun. At the other side of the spectrum are stellar mass black holes, objects with a mass comparable to that of our Sun. Then there’s mid-sized black holes, or intermediate mass black holes (IMBH), at about 10 to 100 times the mass of our Sun. Astronomers also think there are “middleweight” black holes out there, weighing in anywhere from 20,000 to 90,000 times the sun’s mass — but more observations are need to confirm these findings.
Small black holes are known for their high-energy X-rays, while larger black holes give off low-energy X-rays. Also known as hard and soft X-rays, these emissions are caused not by the black hole itself, but by the rapidly accelerating mass of matter swirling around it. So, the lower the X-ray energy, the bigger the black hole.
Tiny But Powerful
Which leads us to the strange black hole in question, M101 ULX-1. This thing is giving off low-energy X-rays and insanely bright illumination — flares that are 100 times brighter than usual, thus designating the system an ultraluminous X-ray source (known as ULX). Ordinary stellar black holes can’t emit flashes that bright — at least not unless it’s consuming mass at an unexpectedly higher rate.
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http://io9.com/small-black-holes-are-deadlier-than-previously-thought-1473180132
