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New Class of Galaxy Discovered
Posted by
Soulskill
on Wed Jul 29, 2009 08:16 AM
from the give-peas-a-chance dept.
from the give-peas-a-chance dept.
fructose sends along this excerpt from Space Daily:
"A team of astronomers has discovered a group of rare galaxies called the 'Green Peas' with the help of citizen scientists working through an online project called Galaxy Zoo. The finding could lend unique insights into how galaxies form stars in the early universe. ... Of the 1 million galaxies in Galaxy Zoo's image bank, only about 250 are in the new 'Green Pea' type. Galaxy Zoo is claiming this as a success of the 'citizen scientist' effort that they spearheaded. ... The galaxies, which are between 1.5 billion and 5 billion light years away, are 10 times smaller than our own Milky Way galaxy and 100 times less massive. But surprisingly, given their small size, they are forming stars 10 times faster than the Milky Way. 'They're growing at an incredible rate,' said Kevin Schawinski, a postdoctoral associate at Yale and one of Galaxy Zoo's founders. 'These galaxies would have been normal in the early universe, but we just don't see such active galaxies today. Understanding the Green Peas may tell us something about how stars were formed in the early universe and how galaxies evolve.'"
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Galaxy Zoo Produces a Rare Specimen 188 comments
We discussed the Galaxy Zoo project soon after it launched last summer. Science News is now following developments about an odd celestial object
that is fueling a lot of excitement among astronomers around the world. In August, a Dutch schoolteacher named Hanny, in the process of characterizing galaxy images, noticed a peculiar object and posted a query about it on the Galaxy Zoo blog. She called it a "Voorwerp," which Science News says is Dutch for "thing" but which Google translates as "subject." Hanny's Voorwerp emits mostly green light (the earlier report said blue). The best guess astronomers have now is that the Voorwerp is emitting "ghost light," i.e. it is "lit by the ultraviolet light and X-rays from a quasar that has vanished in the last 100,000 years," to quote astronomer Bill Keel. "As far as we can tell, it's an unprecedented thing," Keel added. Researchers are scrambling to book time on the Hubble and other major telescopes to get a closer look.
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Distributed Project To Classify SDSS Galaxies 35 comments
Xandu writes "Be part of a human Beowulf by helping classify millions of galaxies from the SDSS at the Galaxy Zoo. From their about page, "Those involved are directly contributing to scientific research, while getting an opportunity to view the beautiful and varied galaxies that inhabit our universe. Why do we need people to do this, rather than just using a computer? The simple answer is that the human brain is much better at recognizing patterns than a computer. Galaxies are complicated objects that vary in appearance enormously, and yet in some ways they can be very similar. We could write a computer program to classify these galaxies, and many researchers have, but so far none have really done a good enough job. We have not been able to make computers 'see past' the complexity, to reliably identify the similarities that appear obvious to our eyes and brain. For now, and probably for some time yet, people do the best job of classifying galaxies."
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so do they exist in their current form? (Score:2, Insightful)
5 billion light years away means that we're seeing them how they were 5 billion years ago. Do they even exist in their current form or did they merge into larger galaxies to take advantage of synergies?
Re:so do they exist in their current form? (Score:5, Funny)
If you'd patiently wait 5 billion more years, you'd know the answer.
Parent
RTFA (Score:2)
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The green stars were some of the most fun...
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As long as they stay away like that, I'm fine?
What if they have greenfly [wikipedia.org]?
Registered trademarks (Score:3, Interesting)
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Indeed, and they also missed out on calling these Galactica, instead of Green Peas
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See this is what happens when all the good names are already taken - a serious project aimed at cataloging distant galaxies is forced to call itself "Galaxy Zoo".
Isn't this also how early morning rush hour radio shows get named?
Less massive but prolific star creators (Score:2, Insightful)
There is a theory that the expansion of a galaxy "tears" spacetime and creates an energy differential. The energy differential then, as special relativity predicts, transmutes to matter thus creating the matter to form stars.
Given that it is the expansion of the galaxy that causes the creation of matter, it makes sense that smaller, more active galaxies would be able to create new stars.
Re: (Score:3, Informative)
Given that it is the expansion of the galaxy that causes the creation of matter, it makes sense that smaller, more active galaxies would be able to create new stars.
I don't know how to respond to this statement. This is the tenth time I've written something before erasing it to start over to sound less inflammatory. I guess I'd just like a citation to this "theory" of the diffusion of matter begetting more matter. It sounds like some whacked-out solid state universe theory.
Re: (Score:3, Informative)
The OP's insane speculation reminds me of the Electric Universe [wikipedia.org] crazies. Every field has its lunatic fringe.
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Galaxy Zoo is a worthy project (Score:2, Interesting)
My pre-teen kids LOVE Galaxy Zoo...they feel they're really helping push out the boundaries of knowledge, and I get lots of teachable moments.
Time to be pendantic! (Score:5, Insightful)
"10 times smaller than our own Milky Way galaxy and 100 times less massive"
10 times smaller?
100 times less massive?
Isn't it 1/10 the size and 1/100 the mass?
In order to be "10 times smaller than $foo" or "100 times less massive than $foo" doesn't there need to be another point of reference?
I know I'm picking nits, but this is slashdot. People should know better. This bugs me like less vs. fewer, there/their/they're, your/you're, and so forth. I understand it is simply a colloquialism arising from poor grammar among the masses, but in the case of a scientific article, poor writing makes it more difficult to take the writer seriously.
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No - 10x smaller means 100x less area to deal with.
If you had a brother that was twice as tall as you, but all body parts were proportional to you, his shadow's area would be 4x yours (length x width) and he would weigh 8x as much as you do (l x w x h).
So galaxies are typically sized up by their diameter. If it's 1/10th the diameter, and area = Pi*r^2, then we're at 1/100th of the area, so the stars can be distributed just like ours and it all works out (although, the other galaxy would have to be the same
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I think the problem here is your reading comphrehension skills, from the line you quoted it should be pretty clear that the point of reference is the Milky Way.
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And there you have it, the other reference point is quite obviously 0. I don't quite see what the fuss is all about?
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The fuss is over the fact that saying something is 10 times smaller than something else means that the thing you're comparing it to is, itself, already considered small. But compared to what? It's meaningless. Shorter, and more accurate to simply say "it's a tenth the size."
People drag out the "ten times..." type stuff when they're trying to sensationalize something that's... not sensational. It's like some sophomore trying to add words to an essay that ha
Re:Time to be pendantic! (Score:4, Informative)
Draw it on a number line: 10 is ten times larger than 1 because it is ten times farther from 0 on a number line. 1 is ten times less than x because it is ten times farther from y on a number line. Go on, fill in the values for x and y.
No, 10 is ten times larger than 1 because the ratio of their sizes is 10:1.
1 is ten times smaller than 10 because the ratio of their sizes is 1:10.
It's about relative not absolute size difference. That's why they say "10 times smaller" rather than "10 units smaller". "Times" is your clue that you're dealing with multiplication, i.e. ratios.
The language is perfectly clear, correct, and unambiguous. No, your reading comprehension is not fine.
Parent
X times (what?) less... (Score:2)
Draw it on a number line: 10 is ten times larger than 1 because it is ten times farther from 0 on a number line. 1 is ten times less than x because it is ten times farther from y on a number line. Go on, fill in the values for x and y.
No, 10 is ten times larger than 1 because the ratio of their sizes is 10:1.
1 is ten times smaller than 10 because the ratio of their sizes is 1:10.
The basic problem is a lot clearer if you're dealing in percentages:
3 is 50% larger than 2. (3 = 2 + 50% of 2)
2 is 33% smaller than 3. (2 = 3 - 33% of 3)
2 is not generally considered 50% smaller than 3, even though 3/2=1.5. Nor is it considered 66% smaller than 3, even though 2/3=66.6%.
The basic ambiguity when talking about relative factors that separate two quantities (particularly when attached to concepts like smaller, colder, etc. - inverse scales) is what your baseline of measurement is. Largeness
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The language is perfectly clear, correct, and unambiguous.
It's oxymoronic to say "times smaller".
You're suggesting implied reciprocals where "x times smaller than" means "one xth the size of" when the latter is perfectly fine English just to avoid explicitly mentioning a fraction.
It makes as much sense as talking about the "near distant" future.
Re:Time to be pendantic! (Score:5, Insightful)
It's oxymoronic to say "times smaller".
No it isn't, unless you think you can only multiply by values larger than one, which would simply be moronic.
You're suggesting implied reciprocals means "one xth the size of" when the latter is perfectly fine English just to avoid explicitly mentioning a fraction.
Yes, heaven forbid there be multiple correct and clear ways to say the same thing in English. *eyeroll* In some cases it flows better than using fractions.
It makes as much sense as talking about the "near distant" future.
No, it makes perfect sense as long as you understand what it means. Which isn't complicated, and now you know it, so there should be no further issues with this perfectly clear and unambiguous language.
Parent
Re:Time to be pendantic! (Score:4, Interesting)
10^1 times smaller = 10^-1 times bigger, never really managed to see the problem with it. It's perfectly unambigious since it makes no sense to refer to less than nothing. Things like there/their/they're that actually have three different meanings are much more annoying.
Parent
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No, the word smaller is entirely ambiguous in this case because it assumes that one thing is small (compared to what?), and another this is ten times more so. But if you don't have some baseline, the use of smaller ("more small than the first thing, which is already small, and here's why we consider it to be small...") makes no sense. Use of "smaller" presumes familiarity with the overall scale of things, and why the two sizes in question mean something, in relation to the larg
Re:Time to be pendantic! (Score:5, Informative)
It's standard English and has been for hundreds of years.
Yes mathematically it makes no sense, but language isn't mathematics. And look you understood that it meant 1/10th and 1/100th so from a linguistically it expressed what was intended just fine, even to people who think in math instead of language.
Unless you're arguing "smaller' needs a qualifier to indicate it means volume. Even that seems a stretch since there are only two options, volume and mass, and the mass is taken by the 100x part.
Parent
Re: (Score:2)
10 times smaller?
100 times less massive?
Isn't it 1/10 the size and 1/100 the mass?
Why yes, that is precisely what "10 times smaller" and "100 times less massive" means.
I know I'm picking nits, but this is slashdot. People should know better.
Yes, you should know better. The language is fine.
I understand it is simply a colloquialism arising from poor grammar among the masses, but in the case of a scientific article, poor writing makes it more difficult to take the writer seriously.
Yes, poor grammar from the
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1 dimension vs 2 dimensions... assuming these galaxies are flat.
1x1 = 1.
10x10 = 100.
10x wider, 100x more area.
That was easy.
Parent post wasn't complaining that a 3-dimensional object that's 10 times wider should necessarily be 10^3 times more massive (though both happen to be true of your mom) - rather, parent post was simply making the point that to say something is ten times smaller than something is fairly nonsensical...
Where we come from (Score:2)
The finding could lend unique insights into how galaxies form stars in the early universe.
Yes we got that from all the other thousands of astronomy articles reporting new findings. This unifying goal of astronomers better be the question to 42.
Oh, another expansion pack (Score:5, Funny)
Great, another overpriced expansion pack. I guess sales from the last time they added a class have dropped, so astronomers are making new areas and classes rather than trying to balance the existing content.
NERF ANDROMEDA!
Just random chance we see no recent ones? (Score:5, Interesting)
Given their density within the 5 billion light year sphere, it should be possible to calculate the odds of having 1.5 billion light years to the closest one.
Re: (Score:3, Informative)
It's not quite so straightforward due to the complexities of how the peas are actually selected, I think. http://arxiv.org/pdf/0907.4155v1 is the paper - section 2 and 5 might be of interest with respect to this sort of question.
Why a new class? (Score:3, Interesting)
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Re: (Score:3, Informative)
Basically young stars have a different kind of emission to old stars. You can essentially count up the amount of light from young stars and work out how much star formation you need to have that population.
Re:Why a new class? (Score:4, Informative)
Parent
Re: (Score:3, Informative)
HST images were needed to investigate the morphology - the shapes just couldn't be picked out in the original images as the galaxies are so compact. However, it looks like a number of them have complex shapes hinting that they are or have recently been involved in mergers with other galaxies. We don't have much to go on at the moment though.
Galaxy Class Color (Score:2)
We already have dwarf galaxies, so its size doesn't matter. I've never heard of a galaxy class based on color.
Well, according to Probert, Galaxy Class [probertdesigns.com] is duck-egg blue with sky blue aztecing... It was just when they filmed it that they desaturated the color a bit to give it the more grayish appearance seen on TV. Also, the smooth hull seen on the early model was intentional, as one would expect that on a massive ship, small details would be almost impossible to pick out. But, of course, that's not what audiences expect: if something looks plain, it looks fake... So later on features like the large lounge window
Peas were user discovery (Score:5, Informative)
I've spent a lot of hours classifying galaxies at GalaxyZoo. The abstract sense of making a tiny contribution to research gets thin real fast. What keeps me coming back is the surprise factor. You'll click away sorting boring balls and streaks and then up pops a perfect barred-spiral, or a swooshy collision or an oddity that doesn't fit any of the categories, and wakes you up. There are millions of galaxies in the deep-field surveys that are the source, most of them never looked at individually, and you never know what the software will toss up next.
The site has an active and supportive forum community, and it was in the forums that the users -- not the astronomy post-docs who run the site -- first commented on the little green balls, suggested they might represent a unique class, and started collecting them as posts on a thread. There are user-run threads going on for other odd types of galaxy some of which might ultimately turn into research topics as well.
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no center and no beginning (Score:3, Interesting)
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There may have been a time when we didn't have tools for explaining the universe besides appeals to personal aesthetics, but today we've got things like formulating hypothesis that explain past observations and lead to empirically falsifiable predictions of future observations, and then constructing experimenets to attempt to falsify those predictions.
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For the record, everything about Big Bang cosmogony references redshift as being a property of distance. There does not explain several celestial objects where a high redshift object is physically connected to a low-redshift object. I have heard an alternate theory that redshift is a prope
Like Orson Welles said... (Score:2)
Time is relative isn't it? (Score:3, Interesting)
The galaxies, which are between 1.5 billion and 5 billion light years away, are 10 times smaller than our own Milky Way galaxy and 100 times less massive. But surprisingly, given their small size, they are forming stars 10 times faster than the Milky Way.
Isn't there some sort of theory about time and it's constant slowing or something? If something appears 5 billion light years away and yet appears to be forming stars 10 times faster than our local system, could that not be somehow relevant to the passage of time either 5 billion years in the past?
If you can't read this because, when I press post, the entire universe changes into something completely new, then I'll know that this means that I was right and that I fucking solved it.
If you can read this line, then let it be known that I've had a lot of coffee this morning, and very little food. That's my story and I'm sticking to it.
Odd things these peas (Score:3, Informative)
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Astronomy [feeddistiller.com] Feed @ Feed Distiller [feeddistiller.com]
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What if they're not peas... but infact Nuts... or indeed, beans. We need more research into them before we go classifying them definitly
Obligatory (Score:2)
Do you like peas?
Do you like cheesy peas?
Then you'll love these!
New Squeezy Cheesy Peas!
They're squeezy!
They're cheesy!
They're peasy!
They're Squeezy Cheesy Peas!
(Now available in Strawberry flavour!)
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The peas were not named by a scientist.