The image above shows two supermassive black holes orbiting each other. It is a composite image where the blue/white indicates x-rays and the pink indicates radio wavelengths. It may look like they are orbiting closely, but the black holes are about 25,000 light years apart, which is about the same distance the Sun is from the center of the Milky Way.
Two of a Kind
A new paper in Nature has announced the discovery of a close binary of supermassive black holes. Known as J1502SE and J1502SW, the two black holes are estimated to have a mass of about 100 million solar masses each, and they are separated by only 450 light years. This means they orbit each other once every 4 million years. For …
Animal Magnetism
One of the challenges to understanding black holes is that when things get close to a black hole, things get complicated. We actually have a good description of black holes by themselves, but the description of the heated material near a black hole is complex. To understand the behavior of this material you need to account for not only the gravitational attraction of the black hole, but also things such as magnetic fields. To model active black holes, you need sophisticated computer simulations, and those simulations rely on certain assumptions about how black holes interact.
No Doughnut
Within most galaxies is a supermassive black hole. These black holes can have a mass of millions or even billions of Suns. When actively consuming material, these black holes can produce tremendous amounts of energy, and can be seen as quasars, blazars and radio galaxies, depending upon the way they are oriented relative to our vantage point. At least that’s been our understanding. But now a new paper in the Astrophysical Journal has thrown a wrench in one part of that idea.
Heart of Darkness
Star formation within a galaxy is a complex process. We have models of galaxy formation, but one of the difficulties with these models has been that they predict a greater formation of stars in large galaxies than we observe. This would seem to indicate that there is some mechanism that hinders star formation within large galaxies. Basically at some point in the galaxy’s formation there must be something that pushes gas out of the galaxy, preventing it from forming into stellar nurseries.
Massive Speed
We now know that most galaxies have a supermassive black hole in their center. One of the ways to determine the mass is called reverberation mapping. By looking at variations in the brightness of active galactic nuclei, you can determine the size of the black hole. But we can only do this for about 40 galaxies, so it would be nice to have another way to determine black hole mass. It turns out there is, using a relation known as the M-sigma relation.
Black Holes
The basic idea of a black hole is simple. Imagine tossing a ball into the air. It goes up to a certain height, and then back down. If you toss the ball faster, the ball rises higher, but it still eventually falls. Now suppose you could toss the ball as fast as you like. Could you toss the ball so fast it doesn’t fall back down?
Space Detective
A research team studied photographic plates from the Harvard College Observatory. From the plates they were able to gather about 500 historical data points. This allowed them to prove that two supermassive black holes are orbiting each other.
More Massive Evidence
Related to my previous post, if you’d like to se an animation of the central S-stars, check out this video.
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