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"Mystery of 'Missing Physics' in the Universe" --Solved by CalTech Astrophysicists


  Sn94d-1 (1)


Although the majority of the "normal" matter exists in stars at the center of galaxies, in actuality these stars account for less than 10 percent of the matter in the universe. A new set of simulations show that the energy released by individual stars within galaxies can have a substantial effect on where matter is located in the universe.

The Feedback in Realistic Environments, or FIRE, project is the culmination of a multiyear, multiuniversity effort that—for the first time—simulates the evolution of galaxies from shortly after the Big Bang through today. The first simulation to factor in the realistic effects of stars on their galaxies, FIRE results suggest that the radiation from stars is powerful enough to push matter out of galaxies. And this push is enough to account for the "missing" galactic mass in previous calculations, says Philip Hopkins, assistant professor of theoretical astrophysics at the California Institute of Technology (Caltech) and lead author of a paper resulting from the project.

"People have guessed for a long time that the 'missing physics' in these models was what we call feedback from stars," Hopkins says. "When stars form, they should have a dramatic impact on the galaxies in which they arise, through the radiation they emit, the winds they blow off of their surfaces, and their explosions as supernovae. Previously, it has not been possible to directly follow any of these processes within a galaxy, so the earlier models simply estimated—indirectly—the impact of these effects."

By incorporating the data of individual stars into whole-galaxy models, Hopkins and his colleagues can look at the actual effects of star feedback—how radiation from stars "pushes" on galactic matter—in each of the galaxies they study. With new and improved computer codes, Hopkins and his colleagues can now focus their model on specific galaxies, using what are called zoom-in simulations. "Zoom-in simulations allow you to 'cut out' and study just the region of the universe—a few million light-years across, for example—around what's going to become the galaxy you care about," he says. "It would be crazy expensive to run simulations of the entire universe—about 50 billion light-years across—all at once, so you just pick one galaxy at a time, and you concentrate all of your resolution there."

A zoomed-in view of evolving stars within galaxies allows the researchers to see the radiation from stars and supernovae explosions blowing large amounts of material out of those galaxies. When they calculate the amount of matter lost from the galaxies during these events, that feedback from stars in the simulation accurately accounts for the low masses that have been actually observed in real galaxies. The image at the top of the page shows a Type Ia supernova, SN1994D, exploding in lower left corner of this image of the galaxy NGC 4526 taken by the Hubble Space Telescope (HST).

"The big thing that we are able to explain is that real galaxies are much less massive than they would be if these feedback processes weren't operating," says Hopkins. "So if you care about the structure of a galaxy, you really need to care about star formation and supernovae—and the effect of their feedback on the galaxy."

But once stars push this matter out of the galaxy, where does it go? That's a good question, Hopkins says—and one that the researchers hope to answer by combining their simulations with new observations in the coming months.

"Stars and supernovae seem to produce these galactic superwinds that blow material out into what we call the circum- and intergalactic medium—the space around and between galaxies. It's really timely for us because there are a lot of new observations of the gas in this intergalactic medium right now, many of them coming from Caltech," Hopkins says.

"For example, people have recently found that there are more heavy elements floating around a couple hundred thousand light-years away from a galaxy than are actually inside the galaxy itself. You can track the lost matter by finding these heavy elements; we know they are only made in the fusion in stars, so they had to be inside a galaxy at some point. This fits in with our picture and we can now actually start to map out where this stuff is going."

Although the FIRE simulations can accurately account for the low mass of small- to average-size galaxies, the physics included, as in previous models, can't explain all of the missing mass in very large galaxies—like those larger than our Milky Way. Hopkins and his colleagues have hypothesized that black holes at the centers of these large galaxies might release enough energy to push out the rest of the matter not blown out by stars. "The next step for the simulations is accounting for the energy from black holes that we've mostly ignored for now," he says.

The information provided by the FIRE simulations shows that feedback from stars can alter the growth and history of galaxies in a much more dramatic way than anyone had previously anticipated, Hopkins says. "We've just begun to explore these new surprises, but we hope that these new tools will enable us to study a whole host of open questions in the field."


              Gas image of galaxy formation_hopkins


The still image from the FIRE simulation above shows the gases in a galaxy. Magenta is cold molecular/atomic gas, which forms stars; green is warm ionized gas, most of which cools into a galaxy; red is 'hot' gas, which makes up the galaxy halo.

These results were submitted to the Monthly Notices of the Royal Astronomical Society on November 8, 2013 in a paper titled "Galaxies on FIRE (Feedback In Realistic Environments): Stellar Feedback Explains Cosmologically Inefficient Star Formation." 

The Daily Galaxy via Jessica Stoller-Conrad/CalTech

Image credit: Philip Hopkins/Caltech

The Daily Galaxy via RAS and CalTech


Ok, but what is the relation with the so called "dark matter" and "dark energy" ?

Also, with the recent realization of the number of planets around stars, plus this additional matter sitting between galaxies, does this account for enough matter to negate both dark matter and dark energy?

_ Okay commenters. This new proposed study is another approach that contradicting dark matter and dark energy theory.

no, it doesn`t contradict.Large masses of Dark Matter are guilty of the so called "lensing" the light of the very far galaxies and Dark Energy is guilty (or it seems) of the accelerating speed of galaxies that does limit our view over 14 billion LY.

I think we should start calling imaginary matter and imaginary
energy. The hypothesis of dark matter/energy is so arbitrary
as to be unworkable. We are in our infancy as regards to our
knowledge of the universe.

Wow, an explaination that actually sounds very logical for how galaxies grow and shed material that affect the rest of the universe around galaxies! I really want to hear more on the progress on this research and study.

Galaxies precipitating stellar matter into the Circum and Intergalactic Medium? Radiative outpourings, star-matter showers, and thunder-burst explosions? Cascade material forth, beyond Galaxy shores, streams, floods and outflows, fill invisible seas, or an ocean?

Vast reservoirs of galaxy depletion, gas and dust afloat, eroded material from galaxy archipelagos; expelled elements from aging islands: Discovered "Missing mass" in tidal flow? "Dark Matter" in wave pattern found, its shaping force uncovered?

- This interesting insight may account for additional matter ( expelled star-galaxy stuff had to go somewhere ), but does the focused simulation resolve the nebulous mystery of "Mass" in time. Will it expand to explain invisible properties of "Energy"-Space? Time will tell, if it really sheds light on the "Dark" side of the Cosmos.

- Missing "Mass" and "Dark Energy" may be two sides of the same coin. Or two equations of a single unifying explanation. A synthesis which may read-out, in final analysis, one all-illuminating, all-encompassing Universe-concept: Purposeful Creation.

( Now, where is my lead umbrella? )

“I do not know what I may appear to the world, but to myself I seem to have been only like a boy playing on the sea-shore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.”

― Isaac Newton

I expected this result a long time. A lot of mumbo jumbo alternative physics ie supersymmetry,string theory has been pushed as "explanation" Every little anomaly in astronomical observations was used as an excuse to say that the standard model of physics is dead but now its obvious they were jumping the gun.

If there is more matter, why we don't see it?

We should be able to detect most of it inside our own galaxy cluster. But it is not an easy job.

We should have the answer in the months to come...

We have to remember always two things. One, that matter is simply "concentrated" forms of energies (I like to use the plural here). And two, we "see" only photons, albeit frequencies from the shortest highest energy gamma to the longest radio, with eyes and instruments. This in itself limits us to perceive using only photons yet there is much much more to the universe than just photons. Think about it. We are still not "getting it" in that we have no idea what space, time, gravity, magnetism force and electric charge really are. Yes we can experiment with these entities and predict outcomes given fundamental variables, and yes we can manufacture a refrigerator and also a magnet to hold up a shopping list, but ultimately we don't know what the fundamental building block forces of the universe even are. "it is the attraction of X to Y" due to electron spin, throw in "gravitrons" for gravity blabla, but that doesn't explain WHAT the heck it is. It is likely human intelligence can't concept these basic five forces at all but can putz with them, invent with them, use them without knowing really what they are. Man is therefore just a hack. So a brick wall is facing us if we can't get what space, time, gravity, magnetism and electrical charge are...missing completely what a finite understanding of what the universe actually is and how it formed from a point. It's beyond human conception just as the working of a simple pair of scissors is beyond a dog's conception of how it works using leverage and shear. To grasp the universe is humanly impossible.

I recommend reading it to the end.

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