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> Heavyweight Galaxies In The Young Universe
JukriS
Posted: Apr 4 2009, 09:38 AM


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http://www.sciencenews.org/view/generic/id..._young_universe


Heavyweight galaxies in the young universe


Newfound massive galaxies may force theorists to revisit formation models


Peering into the center of five of the youngest clusters of galaxies known in the universe, astronomers recently found several full-grown, cigar-chomping adults among the myriad of toddlers. The remote galaxies hail from a time when the 13.7-billion-year-old cosmos was less than 5 billion years old. Yet measurements reveal that the bodies are just as massive as galaxies like the modern-day Milky Way, which took at least 10 billions years to mature.

The findings appear to call into question the leading theory of galaxy formation, known as the dark matter model — at least as it applies to the dense regions where galaxies congregate into clusters, says Chris Collins, an astronomer at the Liverpool John Moores University in England. He and his colleagues used the infrared Subaru telescope atop Hawaii’s Mauna Kea to observe the galaxies, and the team describes the findings in the April 2 Nature.

“No doubt the theorists will want to say that tweaking [the model] in very dense regions will suffice, but I think the problem could be more general than that,” Collins says.

The highly successful model holds that the gravity of a proposed, invisible material known as cold dark matter draws together gas and stars to form galaxies. Due to the properties of dark matter, the model always builds tiny, lightweight galaxies first, merging these small-fry to make bigger bodies. Indeed, dark matter simulations suggest that at such a young age, the galaxies the team examined should have attained only 20 percent of the weight that the astronomers observed.

In the dense environment of a cluster galaxy formation is predicted to occur more quickly. Nonetheless, there doesn’t seem to have been enough time, some 4 billion to 5 billion years after the Big Bang, for the five massive galaxies to have formed by the merging of smaller galaxies, according to the model. The findings suggest that some massive galaxies formed wholesale, rather than building up stars and gas little by little as they cannibalized their neighbors.

“These observations are certainly surprising,” comments theorist Gus Evrard of the University of Michigan in Ann Arbor. Although more data and even larger-scale simulations are needed to determine whether the observations and theory are truly inconsistent, “the difference between nature’s brightest cluster galaxies and the simulated sample is quite striking,” he adds.

Evrard is a collaborator on the Millennium Simulation, an international effort that combines the largest supercomputer simulation of the growth of dark matter ever attempted with new techniques for tracking the evolution of the visible universe. Collins’ team directly compared its observations with the masses of galaxies predicted by this simulation when the universe was about one-third its current age.

“Our result is strong evidence that, for reasons we as yet do not understand, the process of galaxy assembly at early times was much more rapid and efficient than the [dark matter model] in the simulations would have us believe,” Collins says. Although the dark matter scenario for galaxy formation accurately predicts many features over a wide range of cosmic history, “it seems that in these extreme cluster environments, something else is needed.”

In the dense regions examined by Collins’ team the simulations predict extremely rapid growth. But even in these regions the masses of the galaxies were much heavier than the model allowed.

Over the past few years, other astronomers have peered even further back in time and also found some monster galaxies among the newborns (SN: 10/8/05, p. 235). These heavyweights, although less massive than the ones found by Collins and his colleagues, would have had much less time to bulk up and could have put even tighter limits on models of galaxy formation. However, theorists argue that dark matter models allow a few statistical oddballs. Modelers explain away the handful of early massive galaxies as extremely rare objects that happened to be in the densest dark matter regions, Collins says.

In contrast, galaxy clusters aren’t rare. Moreover, the rapid growth rate of galaxies in clusters is already included in the Millennium Simulation.

One reason that the dark matter model may fail to produce massive galaxies rapidly is that at high densities, nearby gas gravitationally snared by a young galaxy would be compressed quickly and heated. Hot gas cannot form stars and in addition would likely loiter in the halo of the young galaxy rather than sinking toward the center to add to the system’s mass.

A report in the Jan. 22 Nature by Avishai Dekel of the Hebrew University of Jerusalem and his colleagues offers a possible solution to this cosmic conundrum (SN: 3/22/08, p. 186). His team’s high-resolution simulations show that some gas funnels toward the center of the galaxy before the gas heats up and can therefore make stars. That would mean that galaxies could bulk up more efficiently in the past.

“Dekel’s stuff points to the underlying difficulties of forming large galaxies quickly and suggests a nice possible way out, but even here it may not be the last word,” Collins says. “I think our data will stimulate more theoretical work.”

In their models, theorists could also attempt to ramp up the rate at which gas turns into stars in the brightest members of galaxy clusters, Evrard suggests. However, he cautions that it could be difficult to fatten up only the brightest members while leaving neighboring galaxies svelte. “The unintended consequence could be gigantic galaxies in today’s universe that aren’t seen and they certainly would be easy to see,” he says.

Speaking of the distance to the observed galaxies, Evrard says, “The observers have laid out a 10 billion light-year tightrope and challenged the theorists to balance on it. It may not be easy.”


It is time to think about new way, you know!


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HenisDov
Posted: Apr 8 2009, 03:10 PM


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On Energy, Mass, Gravity, And Galaxies Clusters -
A Commonsensible Recapitulation


A. "Heavyweight galaxies in the young universe"
http://www.sciencenews.org/view/generic/id..._young_universe
New observations of full-grown galaxies in the young universe may force astrophysicists to revise their leading theory of galaxy formation, at least as it applies to regions where galaxies congregate into clusters.


B. Some brief notes in "Light On Dark Matter?"
, at
http://www.physforum.com/index.php?showtop...=0&#entry373127

- "Galaxy Clusters Evolved By Dispersion, Not By Conglomeration"
- Introduction of E=Total[m(1 + D)]
- "Dark Energy And Matter And The Emperor's New Clothes"
- "Evolutionary Cosmology: Ordained Or Random"
- "“Movie” Of Microwave Pulse Transitioning From Quantum To Classical Physics"
- "Broken Symmetry" Is Physics' Term Of Biology's "Evolution"
- "A Glimpse Of Forces-Matter-Life Unified Theory"


C. Commonsensible conception of gravity

1. According to the standard model, which describes all the forces in nature except gravity, all elementary particles were born massless. Interactions with the proposed Higgs field would slow down some of the particles and endow them with mass. Finding the Higgs — or proving it does not exist — has therefore become one of the most important quests in particle physics.

However, for a commonsensible primitive mind with a commonsensible universe represented by
E=Total[m(1 + D)] , this conceptual equation describes gravity. It does not explain gravity. It describes it. It applies to the whole universe and to every and all specific cases, regardless of size.

2. Thus gravity is simply another face of the total cosmic energy. Thus gravity is THE cosmic parent of phenomena such as black holes and life. It is the display of THE all-pervasive-embracive strained space texture, laid down by the expanding galactic clusters, also noticed in the expanding energy backlashes into various constructs of temporary constrained energy packages.


3. "Extrapolation of the expansion of the universe backwards in time to the early hot dense "Big Bang" phase, using general relativity, yields an infinite density and temperature at a finite time in the past.
At age 10^-35 seconds the Universe begins with a cataclysm that generates space and time, as well as all the matter and energy the Universe will ever hold."

At D=0, E was = m and both E and m were, together, all the energy and matter the Universe will ever hold. Since the onset of the cataclysm E remains constant and m diminishes as D increases.
The increase of D is the inflation, followed by expansion, of what became the galactic clusters.

At 10^-35 seconds, D in E=Total[m(1 + D)] was already a fraction of a second above zero. This is when gravity started. This is what started gravity. At this instance starts the space texture, starts the straining of the space texture, and starts the "space texture memory", gravity, that will eventually overcome expansion and initiate re-impansion back to singularity.


D. Commonsensible conception of the forces other than gravity

The forces other than gravity are, commonsensibly, forces involved in conjunction with evolution:
http://royalsociety.org/downloaddoc.asp?id=4770

The farthest we go in reductionism in Everything, including in Life, we shall still end up with wholism, until we arrive at energy. Energy is the base element of everything and of all in the universe. At the beginning was the energy singularity, at the end will be near zero mass and an infinite dispersion of the beginning energy, and in-between, the universe undergoes continuous evolution consisting of myriad energy-to-energy and energy-to-mass-to-energy transformations.

The universe, and everything in it, are continuously evolving, and all the evolutions are intertwined.


Dov Henis
(Comments From The 22nd Century)
Life's Manifest
http://www.the-scientist.com/community/pos...st/112.page#578
EVOLUTION Beyond Darwin 200
http://www.physforum.com/index.php?showtop...05&#entry396201
http://www.the-scientist.com/community/pos...0/122.page#1407
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AlexG
Posted: Apr 8 2009, 03:28 PM


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Any time you see the word commonsensible used in physics, you know what follows is crap.


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Its the way nature is!
If you dont like it, go somewhere else....
To another universe, where the rules are simpler
Philosophically more pleasing, more psychologically easy
Prof Richard Fyenman (1979) .....

God does not roll dice with the Universe" - A. Einstein

"God not only plays dice with the Universe, He rolls them where you can't see" - N. Bohr


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Beer w/Straw
Posted: Apr 8 2009, 04:33 PM


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QUOTE (AlexG @ Apr 8 2009, 03:28 PM)
Any time you see the word commonsensible used in physics, you know what follows is crap.

Sorry, but I just can't be bothered to use the "find on this page" feature.


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Transcendental Ignorance!
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AlexG
Posted: Apr 8 2009, 08:46 PM


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It is a comment on his 'work'.


--------------------
Its the way nature is!
If you dont like it, go somewhere else....
To another universe, where the rules are simpler
Philosophically more pleasing, more psychologically easy
Prof Richard Fyenman (1979) .....

God does not roll dice with the Universe" - A. Einstein

"God not only plays dice with the Universe, He rolls them where you can't see" - N. Bohr


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Granouille
Posted: Apr 8 2009, 09:19 PM


Et le cheval que vous roulé sur!
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Want another vote on that? laugh.gif

It just amazes me that people who probably don't appear to be freaks go through their everyday lives unnoticed, until they spew faeces here...

God Save the Internet! rolleyes.gif


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Trippy
Posted: Apr 8 2009, 10:02 PM


I'm with stupid.
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QUOTE (Quatermass @ Apr 9 2009, 07:36 AM)
Language evolves. New words come out all the time. They're good they survive. If not, they don't. Comment on his work and not his use of language.

Why do you seem to be assuming it's a new word?

(and yes, I agree with AlexG anything claiming to be possessing, proceeding from, or exhibiting good judgment and prudence: balanced, commonsensical, judicious, levelheaded, prudent, rational, reasonable, sagacious, sage, sane, sapient, sensible, sound, well-founded, well-grounded, and/or wise, probably isn't, especially when what follows makes no attempt to present a balanced argument and presents only carefully selected bias).

This post has been edited by Trippy on Apr 8 2009, 10:03 PM


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Beer w/Straw
Posted: Apr 9 2009, 03:19 AM


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QUOTE (AlexG @ Apr 8 2009, 03:28 PM)
Any time you see the word commonsensible used in physics, you know what follows is crap.



QUOTE (Beer w/Straw @ Apr 8 2009, 04:33 PM)
Sorry, but I just can't be bothered to use the "find on this page" feature.





LOL I read the post laugh.gif laugh.gif laugh.gif

This post has been edited by Beer w/Straw on Apr 9 2009, 03:23 AM


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Transcendental Ignorance!
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