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A montage of the six Green Pea galaxies that University of Michigan astronomy researchers studied. Image credit: Anne Jaskot

‘Green Peas’ Offer Tiny Clues to Early Universe

5 Apr , 2013

by

Today, we see an unobstructed view of the cosmos in all directions. But, a time existed near the Big Bang when the space between galaxies was an opaque fog where nothing could be seen. And according to two University of Michigan researchers, rare Green Pea galaxies, discovered in 2007, could offer clues into a pivotal step, called reionization, in the Universe’s evolution when space became transparent.

Reionization occurred just a few million years after the Big Bang. During this time, the first stars were beginning to blaze forth and galaxies. Astronomers believe these massive stars blasted the early universe with high-energy ultraviolet light. The UV light interacted with the neutral hydrogen gas it met, scraping off electrons and leaving behind a plasma of negatively charged electrons and positively charged hydrogen ions.

“We think this is what happened but when we looked at galaxies nearby, the high-energy radiation doesn’t appear to make it out. There’s been a push to find some galaxies that show signs of radiation escaping,” Anne Jaskot, a doctoral student in astronomy, says in a press release.

In findings released in the current edition of the Astrophysical Journal, Jaskot and Sally Oey, an associate professor of astronomy, the astronomers focused on six of the most intensely star-forming Green Pea galaxies between one billion and five billion light-years from Earth. The galaxies are compact and closely resemble early galaxies. The objects are thought to be a type of Luminous Blue Compact Galaxy, a type of starburst galaxy where stars are forming at prodigious rates. They were discovered in 2007 by volunteers with the citizen science project Galaxy Zoo. Named “peas” because of their fuzzy green appearance, the galaxies are very small. Scientists estimate that they are no larger than about 16,000 light-years across making them about the size of the Large Magellanic Cloud, a irregular galaxy near our Milky Way Galaxy.

Using data from the Sloan Digital Sky Survey, Jaskot and Oey studied the emission lines from the galaxies to determine how much light was absorbed. Emission lines tell astronomers not only what elements are present in the stars but also much about the intervening space. By studying this interaction, the researchers determined that the galaxies produced more radiation than observed, meaning some must have escaped.

“An analogy might be if you have a tablecloth and you spill something on it. If you see the cloth has been stained all the way to the edges, there’s a good chance it also spilled onto the floor,” Jaskot said. “We’re looking at the gas like the tablecloth and seeing how much light it has absorbed. It has absorbed a lot of light. We’re seeing that the galaxy is saturated with it and there’s probably some extra that spilled off the edges.”

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Lawrence B. Crowell
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Lawrence B. Crowell
April 5, 2013 8:58 PM

At one and five billion light years distance these objects are situation long after the reionization phase
LC

The Latinist
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The Latinist
April 6, 2013 12:03 AM

I think the point is that this is evidence that at least one type of galaxy exists that emits ionizing radiation. Since we previously knew of none but knew that reionization had occurred, this is a sort of proof if concept.

Eric Migdal
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April 5, 2013 11:58 PM

What are the chances that the universe is really infinite with no big bang? Our telescopes are not strong enough to see far enough.

The Latinist
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The Latinist
April 6, 2013 2:20 AM

Not sure what this has to do with the article, but I’ll bite. If you wish to propose that there was no Big Bang, you will need to provide a theory that explains the 90+ years of observations telling us that everything in the universe is moving away from everything else in such a way that approximately 13.82 billion years ago all of space occupied a single point. What is your theory?

WisdomSpirit
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WisdomSpirit
April 6, 2013 12:03 PM

The thought gave me a scare! I bit lightly. I.let go really quickly. The thought gave me the chills too.Take care.

Torbjorn Larsson OM
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Torbjorn Larsson OM
April 6, 2013 3:16 PM

Nitpick: The 13.82 billion figure is from a confusing press conference, it is the age derivable from Planck alone. If we want to use the consolidated data set (say, to compare with WMAPs latest such of 13.77 billion years) from the papers, the best Planck estimate of universe age is 13.80 billion years.

But, he asks, what is 20 million years between friends?

The Latinist
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The Latinist
April 6, 2013 5:55 PM

Thank you for the correction. I have to admit that the article I read on the subject was rather confused, and I have not had the time to review the papers myself.

Rick Holcomb
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April 9, 2013 1:00 AM

‘Tired’ light. I kow that there are reasons to dispute this… but the reaasons are fluctuating left and right.

WisdomSpirit
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WisdomSpirit
April 6, 2013 12:04 PM

Wow what a thought.

Olaf
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Olaf
April 6, 2013 1:16 PM

Strong enough to see at least 13.82 billion years away.

Torbjorn Larsson OM
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Torbjorn Larsson OM
April 6, 2013 3:17 PM

Well, within bounds it is possible we can see that far away. But not as likely, the best age estimate is 13.80 billion years, see the Planck papers.

Torbjorn Larsson OM
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Torbjorn Larsson OM
April 6, 2013 3:08 PM
What are the chances that the universe is really infinite with no big bang? The likelihood that the universe is infinite is good, it is a simple theory and perfectly consistent with the flat space measured. The likelihood that there is no big bang is too small to bother with. Planck measured some big bang features to 25 sigma, which means that the likelihood that it is mistaken (random variation in the data) is something on the order of < 10^-20. But, here is where alternative theories run into trouble, from the first Planck result conference: Go down to the 3d figure in the above link, showing the CMB temperature spectra as measured by Planck. It shows a… Read more »
Greg
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Greg
April 7, 2013 6:42 AM

One of the oddities about inflation is that it likely pushed parts of the universe beyond our ability to observe it. And we don’t know how much of it this applies to. The 13.7 billion years of space we can observe is now due to expansion 47 billion light years apart. Some estimates that inflation created a universe a million times bigger. Others speculate that inflation is ongoing even now at the edges of the universe.

Torbjorn Larsson OM
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Torbjorn Larsson OM
April 7, 2013 3:35 PM
It is unfortunate that inflation doesn’t solve the problem of knowing the topology of the universe, but at least it gives a natural suggestion (flat space). AFAIK we can see from cosmic variance (the observed homogenity at large scales) that the universe extends at least 10 times what we can see in every direction, so at least 1000 times as large as the observable universe. (Jumping over some details on the difference between what we can see now and the OU.) Ongoing inflation is eternal, and that is another basket altogether. I don’t think Planck helped those who are looking at early bubble universe collisions much. The anomalies didn’t move from being low confidence. We may see the… Read more »
Aqua4U
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April 6, 2013 5:19 PM
Careful… you might step on someone’s ‘religious faith’ here? The denizens of the ‘Big Bang’ theory are numerous and wildly vociferous in their united opinion on this subject. It is far too EASY to degrade into a shouting match with the disciples of this faith! They have SO much data (Confirmation bias) to back them up, how could you possibly doubt them? Oh ye ‘Heretic’ of little faith! It’s interesting to note the first words in the Judeo-Christian bible… “In the beginning…” This implies there WAS a beginning, HAD to be and furthermore it insinuates an end? A basic tenet of the ‘Big Bang’ theory and a most curious corollary. Foremost among the basic tenets of the ‘Big… Read more »
The Latinist
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The Latinist
April 6, 2013 5:53 PM
I am not at all sure what you’re trying to imply. Are you suggesting that redshift is not a real phenomenon but has been invented by astronomers? If so, do you have any evidence to support the claim? You could measure it yourself for some objects without too much equipment; have you tried? Or are you suggesting that scientists are manipulating the redshift measurements from which they determine radial velocities of cosmic objects? If so, do you have any evidence to support this claim? Or are you perhaps suggesting that redshift, while real, does not represent a shift in the spectrum due to radial velocity? And, if so, what is your alternative theory for the cause of the… Read more »
Aqua4U
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April 6, 2013 9:57 PM

Red shift exists alright, but the question remains: Have we accurately accounted for all possible variables, including time dilation, gravitational and electro dynamic forces?

The Latinist
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The Latinist
April 7, 2013 1:00 AM

Do you have any evidence that gravitational redshift can account for the observed relationship between distance an redshift? Do you propose that more distant galaxies are systematically more massive than nearer ones, or are you positing some other sort of gravitational time dilation? I’m not sure what you mean by “electro dynamic forces” — what mechanism are you referring to? And do these gravitational and electro dynamic mechanisms you are describing better explain the data we have or make predictions that differ frim those of hubble-law expansion that we could test?

Greg
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Greg
April 7, 2013 6:56 AM

By gravitational anomaly, are you referring to the “axis of evil” problem?

WisdomSpirit
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WisdomSpirit
April 7, 2013 3:46 PM

lol…that was a good one.

Greg
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Greg
April 8, 2013 3:04 AM

I was hoping to get into a conversation on the topic as it applies to the latest Planck data, but that conversation will have to wait for another time.

Aqua4U
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April 8, 2013 4:36 PM

Should be… unaccounted for gravitational anomalies… at quantum scales?

The Latinist
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The Latinist
April 9, 2013 4:09 AM

Again, do you have any evidence that such things exist?

Aqua4U
Member
April 9, 2013 5:12 PM
it’s in my nature I guess? Am ambidextrous with the left side/right brain dominant. Neither of my parents were left handed. I play the fiddle, guitar and baseball right handed… ping pong with either hand, then eat and write left handed. Bottom line is that I’m not your typical left handed hitter… I really like what Leonard Shlain wrote: “We can see that the right hemisphere processes information as an all-at-once holistic gestalt by using multiple incoming, converging determinants and integrating them synthetically. Simultaneously, the opposite of sequential time, is unique to the right brain which functions best in a visio-spatial context, correlating parts to a whole while intuiting diverse relationships among them. Since multiple determinants, multiple emotions,… Read more »
The Latinist
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The Latinist
April 9, 2013 5:38 PM
Sorry, but that is not science. I hope you have not considered this exchange to be a “shouting match,” as I have tried to remain respectful in all my replies, but I am afraid I have to stop here. Your comments appear to be based on nothing more than intuition and insinuations about the motivations of scientists and therefore have no basis in fact. I’ve asked you several times for evidence, and all you’ve offered is pointers to irrelevant articles and some new-age mumbo-jumbo. I don’t really have any interest in your speculation; all I care about is the evidence. Since you seem to be unable to offer any evidence that would suggest that expansion is not the… Read more »
Aqua4U
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April 9, 2013 6:17 PM

Some people don’t see patterns in things….

The Latinist
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The Latinist
April 9, 2013 7:05 PM

Some people recognize that human pattern recognition abilities, while amazing and useful, often see patterns where none exist; and these people have developed a means of testing the patterns they perceive through the application of a standard methodology and an unbending requirement for evidence to support their ideas. Such people are called scientists.

Aqua4U
Member
April 9, 2013 10:06 PM

And yet it took a couple of bicycle mechanics to get us flying…

The Latinist
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The Latinist
April 9, 2013 11:31 PM

The Wright Brothers were great experimentalists. They didn’t build the airplane according to any preconceived notions or ideas of how it “should” look; they tested wing designs in wind tunnels, measured the lifts of various designs, and settled on designs based on the evidence. They were, in other words, scientists.

Aqua4U
Member
April 9, 2013 11:07 PM

‘Spooky action at a distance’ sound familiar? It’s called quantum entanglement. There is supposedly an experiment going up to the ISS… as proposed by the Institute of Physics and German Physical Society’s New Journal of Physics to test this more fully. I hope it flies!

The Latinist
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The Latinist
April 9, 2013 11:37 PM

What does quantum entanglement have to do with anything? Entanglement is an experimentally verified phenomenon which has been observed countless times. It’s definitely not fully understood, but that doesn’t mean it creates a license to speculate wildly about unrelated phenomena. What are you trying to suggest, that quantum entanglement is causing cosmic redshift? If so, I don’t think you understand even the basics if quantum mechanics.

Andrew Planet
Member
April 7, 2013 2:49 PM
@Aqua4U That certainly strikes a chord. It does sound so much like a repetition of Genesis but illustrated with superficial scientific embellishments. Even though one day Big Bang theory might be well proved to be true, even if that in itself is done so partially, it is good to remind ourselves that it is still theory and not yet factually verified. The periodic table of elements had indeed been objectively factually verified by experiment though not the Big Bang theory, I think. I don’t deny an expanding and accelerating universe but only about a century ago people were convinced that the Universe was comprised of just the Milky Way Galaxy. Could the Universe be much bigger? For example,… Read more »
Torbjorn Larsson OM
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Torbjorn Larsson OM
April 7, 2013 3:58 PM

Even though one day Big Bang theory might be well proved to be true,

It is the observed fact, do keep up with Planck et cetera.

We also know that “no big bang” alternatives are completely failed models.

Andrew Planet
Member
April 7, 2013 11:41 PM

@ Torbjörn Larsson You sound so adamantly like a creationist yourself, with all due respect

Dark Gnat
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Dark Gnat
April 8, 2013 5:20 PM

I don’t see anything unusual. Every story has a beginning, and as long as time exists, there will be beginning and endings.

To compare science to religious/mythological texts seems a bit pointless. The creation story in Genesis is there to “set the stage” and wasn’t necessarily meant to be taken literally. It was simply a very poetic way of saying the God created everything.

God is not a testable concept. We can’t confirm or deny the existence of something that can’t be observed or measured, which is rather like many multi-verse ideas, in my opinion.

We can only go with what we have, and the “big bang” seems to make the most sense.

Torbjorn Larsson OM
Member
Torbjorn Larsson OM
April 7, 2013 3:50 PM
Creationists shouldn’t comment on science, it is hilarious and makes deconverts from religion, see Dawkins’s Convert’s Corner. Mostly this is tedious. Planck has already succeeded in making “no big bang” ideas akin to ideas of Flat Earth ideas, or ‘completely failed models’ according to physicists. See my longish comment and why that is obvious – you can see it from the data graphs! You don’t even need to know about redshift and the easy observations, CMB data is enough. So go ahead, be a modern days flat earther. But don’t think we won’t laugh more or less openly. As for looking at strained coincidences with religious texts, it is both tedious and useless. The text you refer to… Read more »
Aqua4U
Member
April 7, 2013 11:44 PM

Here are the figures… http://arxiv.org/pdf/physics/0509163v1.pdf … I can’t say that I am exactly ‘conversant’ with these maths… and that is my greatest liability? Still… I wonder if the whole foundation would shake if one of the fractions were to change?

The Latinist
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The Latinist
April 8, 2013 1:47 AM
The article you linked to is about the effect of the movement of the observer on observed redshift in light emitted from an object at some a angle to the motion of the observer (it should be obvious that there will be a small redshift or blueshift induced by the relative motion of the observer). Its talking about a special case involving the angle at which this doppler shift will be zero due to relativistic effects. The important thing to remember here is that this effect would create blueshift in the direction of the observer’s motion and redshift in the direction. It cannot explain a uniform redshift in all directions relative to the motion of the observer. And… Read more »
Aqua4U
Member
April 8, 2013 2:37 PM

Today’s (04.08.13) APOD contains this red shift look up table and conversant variables.
http://arxiv.org/pdf/1303.5961v1.pdf

TheLastWord316
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TheLastWord316
April 6, 2013 6:09 PM

Must every article on cosmology rely on the tired, trite “origins of the universe” rhetoric? Are all cosmologists ego maniacs? Is it possible to just describe the discovery, without all the heavy handed and completetly unscientific implications?

WisdomSpirit
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WisdomSpirit
April 6, 2013 8:29 PM

Great name…and
. your comment also.

ITSRUF
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ITSRUF
April 6, 2013 11:54 PM

The “origin of the Universe” hyperboles are used to secure funding.

WisdomSpirit
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WisdomSpirit
April 8, 2013 9:11 AM

Thelastword316, You have me interested w/your post-name, also w/your contempt vs the norm. I like your style. Explain please.

WisdomSpirit
Member
WisdomSpirit
April 6, 2013 8:32 PM

It is just so incredible what that one picture conjures up.

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