Somewhere out there, at the most distant reaches of space and time, a vast space-ocean with 140 trillion times more water than the drop that fills Earth’s ocean basins is pouring down the drain of a super black hole, guzzled up and gone forever, forever, forever…. And I worry about wasting water every time I flush the toilet….
The whirlpool Jacuzzi in question is at the heart of a young galaxy 12 billion light years away. We know we’re looking at a young galaxy because at that distance we are seeing the light that left it 12 billion years ago…and since the Universe itself is only 13.7 billion years old, you get the idea….
At this galaxy’s core is quasar APM 08279+5255, an unimaginably powerful object whose engine of potential energy is a supermassive black hole containing some 20 billion solar masses, and whose radiant power—equivalent to about a quadrillion Suns (that’s a thousand trillion smiley Sun faces)—is fueled by goo-gobs of gases falling into the young galaxy’s core (1 goo-gob is equivalent to…well, a lot).
And what gases do we find swirling around this quasar? Well, mingled with the ubiquitous hydrogen and helium that you’d expect to find, astronomers have detected water, 140 trillion times the amount of water in Earth oceans—enough to supply an Earth-style ocean to all of the planets thought to exist in the Milky Way galaxy, 3000 times over!
Dizzy. Head spinning. Numbers too big. What are we talking about anyway, the National Debt?
You might be imagining actual oceans of liquid water flying about out there…but you’ll have to dash that notion on the rocks, since the water (vapor) in question is spread out across a hundred or more light years of space surrounding the black hole, making the actual density of the gas some 300 trillion times thinner even than Earth’s atmosphere….
Still, it’s a lot of water. Water certainly exists in “normal” galaxies, like the Milky Way—this we know from daily experience–but most of it is frozen as ice. A galaxy containing a quasar like APM 08279+5255, however, has a central heating element that puts out plenty of energy to keep the water flying around as a gas.
When a black hole pulls matter from the space around it into its dark depths, that falling matter, accelerated by the black hole’s powerful gravity, heats up and emits intense radiation—electromagnetic waves across the spectrum, from radio waves to X-rays. We detect ordinary black holes within our own galaxy through these emissions.
But when the gases in a young galaxy’s matter-packed core is pulled into its resident super-massive black hole, you get an even brighter beacon—in the case of APM 08279+5255, a quasar, the most luminous type of object in the known universe.
Quasars are quite distant, typically found no closer to us than about 3 billion light years. Taking the light-travel-time into account, what this means is that quasars existed in the earlier ages of the Universe, when galaxies were younger and had a lot more loose material falling into their central black holes. The Milky Way’s own central black hole, with a mass of 4 million Suns, sits relatively quiet today, the space surrounding it clean and not supplying it with the food it would need to shine like a quasar. Maybe it did when it was younger, but no longer (thankfully).
Quasar means “quasi-stellar (star like) radio source,” so-named because these ultra-distant powerhouses were first detected by radio telescopes, and the distant sources of the radio emissions appeared to be coming from compact, point-like spots in space, the same as the light from a star. Today we know of over 200,000 quasars.
When first discovered a few decades ago, astronomers didn’t know what quasars were. They knew that they were very far away due to Doppler shift measurements, but for all their great distance they were very bright as well, so they had to be extremely luminous objects.
In sixth grade I went to a summer camp, and one of my councilors ran an astronomy workshop. Quasars, he said, reading from a book, are mysterious, and might be hot, dense fragments of the “shell” of whatever egg-like thing the Universe was born from in the Big Bang.
Shell fragments from the Universe’s cosmic egg? Well, we’ve come a long way in our understanding of quasars since my childhood….