Image of a black hole via PhysicsWorld

Black holes are some of the most amazing cosmological structures in the universe. We are drawn to them. Perhaps this is because they stand as a kind of sublime horror; they are super massive objects that consume entire worlds. Plus, their awesome size and power is unutterably amazing. However, despite their grandeur, they are exceedingly difficult to study. Try as we may, we really can’t get to the heart of these objects; the singularities themselves rest beyond the realm of physics. But all is not lost. Although we don’t know everything about black holes, we have uncovered some pretty amazing facts. Here, in no particular order, are some of the coolest black holes we’ve ever discovered.


NGC 3842:

At first glance, NGC 3842 seems like a rather unassuming elliptical galaxy. True, it is the brightest galaxy in the Leo cluster, but other than that, it doesn’t seem to be too notable. However, a detailed analysis revealed that this galaxy is hiding something that is truly monstrous.


The black hole at the center of this galaxy is an amazing 9.7 billion solar masses. Saying that it’s "big" is a bit like saying that the Sun is "warm"—it’s an astronomical understatement. Really, it is. Think about it for a moment. That black hole has eaten 9.7 billion Sun-sized stars (or objects of comparative mass). Unsurprisingly, such an amazingly huge object is hard to fathom. Fortunately, there are a plethora of comparisons. For starters, the “point of no return” or event horizon (where the gravitational pull is so great that nothing, not even light, can escape) is five times greater than the orbit of Pluto. This means that the event horizon would extend well beyond the edge of our solar system; our little neighborhood would be swallowed 5 times over. Ultimately, this monster could have consumed entire civilizations—many, many civilizations, in fact.


And the gravitational influence of the black hole would extend over a sphere 4,000 light-years across. Just how far is that? For comparison, The Small Magellanic Cloud (a dwarf galaxy near the Milky Way) has a diameter of some 7,000 light-years and contains several hundred million stars…which is nowhere near 3284’s 9.7 billion solar masses. So this black hole puts an entire galaxy to shame (…a dwarf galaxy, but still).


NGC 1277:


If you’re like me, you probably thought that the last black hole was rather impressive. That’s not too surprising. For a long time, this was the most massive black hole that we knew about, but astronomers recently discovered one that’s even larger. In November of 2012, researchers discovered a black hole that is 17 billion solar masses.This means that the event horizon is more than twice that of NGC 3842’s.


And this black hole is powerful. Not only has it consumed an impressive amount of material, it is ejecting an amazing amount as well. You see, some black holes emit x-rays, gamma-rays, and radio waves from just outside of the event horizon (it is believed that this is caused by gravitational stresses from material revolving around the black hole). Researchers found that about 400 solar masses of material is streaming away from this object at speeds exceeding 4,970 miles per second (8,000 kilometers), which is more than five times more powerful than the previous record holder. Ultimately, this black hole puts out about one hundred times the energy output by all of the stars in our galaxy, so it’s about 2 TRILLION times more energetic than the Sun!


IGR J17091-3624:

When we think of black holes, we generally think of structures like the ones that were previously mentioned—enormous beasts that devour entire star systems. However, not all black holes are interstellar destroyers; some are actually rather smallish. This brings us to IGR J17091-3624. Don’t let the unassuming name throw you; this black hole has a number of surprises.


First, it is believed that this black hole weighs less than three times the Sun's mass. True, an object that is almost three times the mass of the Sun is rather large, but not when we are talking about black holes. IGR J17091-3624 is actually near the theoretical mass boundary where black holes become possible, which means that, if this object were slightly smaller, it never would have been able to form into a black hole. But this tiny beast packs quite the wallop.


Observations from NASA’s Chandra X-ray Observatory indicate that this black hole is generating winds in excess of 20 million miles per hour (32 million kmh). This amazing speed is nearly ten times faster than what has ever been seen from similar stellar-mass black holes (the smaller-sized black holes). Moreover, these speeds match some of the fastest winds generated by supermassive black holes (objects millions or billions of times more massive than IGR J17091-3624). So it seems that the old adage is true: size isn’t everything.


ULAS J1120+0641:


Time is a strange, strange thing. When you spend an evening watching TV, 8 hours will zoom by in what seems like seconds. Conversely, if you spend an afternoon at work, 4 hours seems to take an age. But these things—hours, days, years—they are human measurements. We obviously use these same measurements when talking about the cosmos, but most of the larger structures in the universe (planets, stars, galaxies—even comets) can’t really be measured in years or centuries...even millennia seems like an inappropriate term.


The thing is, when you start talking about objects that are millions or even billions of years old, things like hours and days lose all meaning. Take, for example, ULAS J1120+0641. This is the oldest black hole ever discovered. How old do you think it is? Go on and have a guess….1 billion years? 2 Billion? 7 Billion? Not even close.


It’s 12.9 billion years old. Data indicates that this black hole formed a mere 770 million years after the Big Bang. The distance to the quasar (ie., it’s age) was determined from observations made by the European Southern Observatory via the FORS2 instrument on the Very Large Telescope and instruments on the Gemini North Telescope. These observations showed that the mass of the black hole is about two billion times that of the Sun, which is amazingly large. So large, in fact, that it’s hard to explain so early on after the Big Bang.


Of course, this just means that we have more studying to do and research to conduct. Undoubtedly, there are many more amazing things we’ve yet to discover.

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