An interesting astronomical bit of research just came over the wire: black holes belch dust.
There are a handful of things that truly baffle astronomers. In general they are caused by two observations that contradict each other, or at least an observation that contradicts theory. For example, we know that dust grains — complex aggregations of various minerals and compounds in space — are created in red giants and supernovae. But we see a lot of dust way back in the early Universe, before it seems like there were stars old enough to make it.
A new observation using the Spitzer Space Telescope shows that black holes might be making that dust. Astronomers observed a quasar, a type of galaxy with an extra-bright nucleus, about 8 billion light years away, and specifically the black hole in the center of that quasar. All big galaxies have supermassive black holes in their centers; the one in the Milky Way is about 4 million times the mass of the Sun, but some can be a billion solar masses! If that black hole is gobbling down matter, it can actually wind up spewing a lot of that material back out. The material can be very bright, making it easy to study.
Astronomers took a look at the material coming out of the central black hole in quasar PG2112+059 and found it had a lot more complex dust in it than was previously thought (including the materials that make up sapphires and rubies!). Normally, that kind of dust is generated in stars but is quickly destroyed by nearby bright stars — their UV light can break down the materials — so seeing this much of it implies strongly that it’s coming from the black hole wind itself.
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| The spectrum of the galaxy shows the presence of all kinds of stuff, including corundum, which is a basic ingredient of sapphires and rubies! The observed spectrum is in white/beige, and the models of the spectra of the other materials are in the different colors. They all add up together to make the observed spectrum, and the fit is pretty good. |
This galaxy isn’t really considered to be in the "early" Universe: at 8 billion light years away, we see it as it was when it was only a little more than half the age of the Universe now. But we know these supermassive black holes were around farther back in time, and that in turn means they could have been the source of the dust that has been dogging astronomers.
This is hardly proof, but it does indicate that when astronomers are confronted with a paradox of sorts, they look — and usually find — the knife that cuts the Gordian knot. The next step is to look for these minerals in more quasars, and more distant ones, too.
October 9th, 2007 at 4:26 pm
A quasar 8 billions light years away has a little more than half the current age of the universe? I would say a little less, but I know that cosmological distances aren’t linear. Is that why there is a discrepancy in the numbers?
October 9th, 2007 at 4:28 pm
Gordian Knot? heh heh
http://www.giantitp.com/comics/oots0327.html
October 9th, 2007 at 4:43 pm
Be excellent to each other. Party on, dudes.
October 9th, 2007 at 4:58 pm
Could it be intervening dust? How do we know it belongs to the quasar?
Maybe the quasar is associated with an active galaxy and has been ejected by it and this dust is from the material in the neighborhood of the parent galaxy?
October 9th, 2007 at 5:02 pm
I was on a business trip last week, in a little Connecticut hotel late at night drifting off while watching a show on the Science Channel about super-massive black holes. The program, (apparently a 2001 rerun) briefly touched on a theory that explores the possibility that galactic black holes precede and indeed contribute to the formation of galaxies rather than form as a result of massive star formations within the galaxies. In other words, super-massive galactic black holes are a different animal forming earlier and began causing exterior gases to accelerate, condense and eventually form the early massive galactic stars, thereby contributing to galaxy formation rather than as a result of it. Kind of a weird cart-before-horse idea, but interesting.
October 9th, 2007 at 5:28 pm
I remember that one, man. It was on the “Inside the Swartzchild Radius”
album:
“Don’t hang on…
Nothing lasts forever but the Earth and Sky…
… and belching black holes.”
Good times.
October 9th, 2007 at 6:20 pm
Imagine Sagan go: “We are hole stuff”. Um, better not.
I wonder what mechanism is responsible. Does it start out as star-made atoms, interstellar hydrogen, or from the particles in Bekenstein-Hawking radiation?
And it is totally cool that 2-4 small features are explained by PAH’s, coming back to Sagan.
October 9th, 2007 at 6:29 pm
OK- but you didn’t explain how all that dust managed to end up in my apartment.
October 9th, 2007 at 6:52 pm
Christian,
There is a mini-black hole in your apartment. As your missing socks fall into the black hole, they emit gamma rays which produce dust-antidust pairs. Due to physics that will only be understood after the LHC comes online, there is an excess of dust over antidust. An inflationary phase then distributes the dust uniformly through your apartment
October 9th, 2007 at 7:03 pm
Sock dust….. It all makes sense now.
October 9th, 2007 at 7:24 pm
What’s that peak at about 16.75?
October 9th, 2007 at 7:52 pm
I sure HOPE something comes out of them. if I never hear the qualifier “…not even light…” applied to the description of how bitchin’ strong black holes are, it’ll be too soon.
October 10th, 2007 at 12:16 am
I’m puzzled. Does this mean that nucleogenesis goes on in accretion disks?
October 10th, 2007 at 6:57 am
A lot of people have said that black holes are like cosmic vacuum cleaners. If indeed they belch dust, then black holes may be even more vacuum-cleaner-like than originally thought.
By the way, “belch” might not be the proper metaphor for what a black hole does. Wouldn’t a better term–one describing a discharge from a black hole–be “fart?”
October 10th, 2007 at 1:17 pm
I did a quick search in the Bible of whether it has reference to black holes and came up with Jude 1:13 (the Message version):
“… Lost stars in outer space
on their way to the black hole.”
There are tons of references to stars, falling stars and of course the formation of the earth (Genesis 1).
http://www.biblegateway.com is a good site to do the searches on. Maybe this will help in the quest for answers.
October 11th, 2007 at 12:52 pm
Andre, here’s Luke 1:10-13 from the KJV, that renaissance translation beloved of fundamentalists:
10: But these speak evil of those things which they know not: but what they know naturally, as brute beasts, in those things they corrupt themselves.
11: Woe unto them! for they have gone in the way of Cain, and ran greedily after the error of Balaam for reward, and perished in the gainsaying of Core.
12: These are spots in your feasts of charity, when they feast with you, feeding themselves without fear: clouds they are without water, carried about of winds; trees whose fruit withereth, without fruit, twice dead, plucked up by the roots;
13: Raging waves of the sea, foaming out their own shame; wandering stars, to whom is reserved the blackness of darkness for ever.
Verse 13 is clearly metaphoric, referring to those individuals in verse 10 who “speak evil of those things which they know not”. Try reading the entire book rather than one verse mistranslated and out of context; this passage has nothing to do with cosmology.