Largest Object in the Universe Discovered

prostoalex writes "Quick, think of the largest object you can imagine. Whatever your imagination delivered it probably wasn't an 'enormous amoeba-like structure 200 light-years wide and made up of galaxies and large bubbles of gas,' a newly found object, as USA Today reports."

Comments

That's 200 Million, not 200 Light Years

[nincehelser]

But what's a few orders of magnitude among friends?

Re:That's 200 Million, not 200 Light Years

[MrNaz]

Agreed. On a cosmic level we have no way of knowing if the known universe is just a small part of a larger structure. As such, all of the known universe could be "single object", so lets be serious about the way we define things, especially in physics.

In my opinion, TFA is a load of crud. An "object" is a single item. To use an astrophysics definition, it is a parcel of matter of contiguous structure bound by atomic or molecular forces (but not magnetic or gravitic) incorporating solid or liquid state matter, but not gasses or plasmas.

Following this definition:

• Earth is an object, but its atmosphere is not part of it.
• The outer gasseous atmosphere of Jupiter is not part of the planet itself, which is made up of liquid and presumably solids as well.
• When the Sun casts off gas in solar flares, that gas ceases to be "part" of the Sun.
• A full baloon is an object that does NOT incorporate the gas it contains.
• Many have spoken of "escape velocities" being the tie that causes an object to become "one" with another. BS BS BS. The Earth and its moon are not one object, nor are the Sun and the Earth.
• Dust is a collection of very many tiny objects. Yes, its a little hard to think of a "dust cloud" as many small objects, but thats the way it is, so deal with it.

Stop with the hyperbole already. A collection of galaxies and gasses and the missing brains of Slashdot readers is not a single object. Calling it one is just an excuse to attract attention to a "hey my discovered object is bigger than yours" competition.

200 != 200,000,000

[Mr. Slippery]

Something 200 light years across is not big (on galactic scales). TFA says the structure here is 200 million LY.

Submission is wrong

[nefele]

First of all, the structure is 200 million light years across. The distance from the Sun to the center of our Galaxy is about 26,000 light years, so 200 light years would not be very impressive in comparison.

Also, the article is somewhat misleading itself, as the blob isn't really a homogenous structure. It's just a group of galaxies packed together more closely than other clusters. So it isn't really that much different from other parts of the Universe.

Re:Submission is wrong

[cswiger2005]

If you hunt down the actual article, they've also been able to see huge formations of gas from which the galaxies formed (presumably), so the structure includes more than just close-packed galaxies:

"A team of astronomers using the Subaru and Keck telescopes on Mauna Kea has discovered giant, three-dimensional filaments of galaxies extending across 200 million light-years of space. These filaments, which formed a mere 2 billion years after the birth of the universe, are the largest-known structures ever discovered. They are studded with more than 30 large concentrations of gas, each up to ten times as massive as our own galaxy. These giant gas clouds are probably the progenitors of the most massive galaxies that exist in the universe today.
[ ... ]
The Subaru observations were successful in finding much fainter objects than previously discovered in this region. (Figure 4) For example, they found 33 new large concentrations of gas along the filamentary structure extending across 100,000 light-years. This is the first time that so many large concentrations of gas, known to astronomers as Lyman alpha blobs, have been discovered in the distant universe.

Astronomers think that such Lyman alpha blobs, named so since they are seen in the Lyman alpha emission line of hydrogen, are probably related to the births of the largest galaxies. In the "gravitational heating" model, the blobs are regions where gas is collapsing under its own gravity to form a galaxy. The "photoionization" model attributes emission from the gas to ionization by ultraviolet light from newborn stars or a massive black hole. The "shock heating" or "galactic superwind" model hypothesizes that the glow of the gas is caused by the death of many massive stars born early in the history of the universe, living out short lives, and then dying in supernova explosions that blow out surrounding gas. Team members Yoshiaki Taniguchi and Yasuhiro Shioya (Ehime University) have been advocating for the galactic superwind model.

Observations with the DEIMOS spectrograph at the Keck II telescope revealed that the gas inside the blobs move with speeds greater that 500 kilometers per second (300 miles per second). The extent of the gas concentrations and the speed of the material within them suggest that these regions must be up to ten times as massive as the Milky Way Galaxy."

PS: The "galactic superwind" theory gets my vote for the coolest theory name!

Re:Large Packets of Gas?

[MindStalker]

Well as stated by others the milky way is 90,000 or .09 million light years across.

SO if its 2000 times as big as our galaxy and we are just NOW being able to see it. Its probably REALLY REALLY far away.. I would guess! :)

Another note our cluster of galaxies called the Virgo cluster which containes most of the visible galaxies such as Andromeda is 100 million light years across.

Press release

[Jugalator]

... and here's the actual press release for the discovery in case you want some more meat than given by the simplified USA Today article.

Re:200 MILLION light-years wide...

[Anonymous Coward]

Why do they claim that this object is the largest in the universe? Isn't the Virgo Supercluster also 200 million light years across? And isn't the Great Attractor theoretically much larger?

Re:The Wall?

[Anonymous Coward]

According to http://curious.astro.cornell.edu/question.php?numb er=604, the Great Wall is 600 M light-years across.

Re:Large Packets of Gas?

[cswiger2005]

Shouldn't the large regions of gas (they say some bigger than the Andromeda Galaxy in dimensions) collapse under gravity and make stars, galaxies, other things? Unless I guess the gas is super hot and full of energy already.

Sure-- that's just what most astronomers expect happened. Remember that when we look really far away, we're also looking really far back in time, back far enough that we're starting to be able to see somethings about the universe before many of the galaxies which exist today existed.

The big questions are about things like how uniform was the distribution of the initial gas, when star formation first started happening what kind of stars appeared, and whether the first stars did interesting things like blow up in nova/supernova-type events, or become giant black holes like many galaxies seem to have, and what that would mean for the clouds of gas and the galaxies being formed from it, etc.