Cosmic Swirly Straws Feed Galaxy


Computer simulations of galaxies growing over billions of years have revealed a likely scenario for how they feed: a cosmic version of swirly straws.

The results show that cold gas — fuel for stars — spirals into the cores of galaxies along filaments, rapidly making its way to their “guts.” Once there, the gas is converted into new stars, and the galaxies bulk up in mass.

“Galaxy formation is really chaotic,” said Kyle Stewart, lead author of the new study appearing in the May 20th issue of the Astrophysical Journal. “It took us several hundred computer processors, over months of time, to simulate and learn more about how this process works.” Stewart, who is now at the California Baptist University in Riverside, Calif., completed the majority of this work while at NASA’s Jet Propulsion Laboratory in Pasadena, Calif.

In the early universe, galaxies formed out of clumps of matter, connected by filaments in a giant cosmic web. Within the galaxies, nuggets of gas cooled and condensed, becoming dense enough to trigger the birth of stars. Our Milky Way spiral galaxy and its billions of stars took shape in this way.

The previous, standard model of galaxy formation held that hot gas sank into the centers of burgeoning galaxies from all directions. Gas clouds were thought to collide into each other, sending out shock waves, which then heated up the gas. The process is similar to jets creating sonic booms, only in the case of galaxies, the in-falling gas travels faster than the speed of sound, piling up into waves. Eventually, the gas cools and sinks to the galactic center. This process was theorized to be slow, taking up to 8 billion years.

Recent research has contradicted this scenario in smaller galaxies, showing that the gas is not heated. An alternate “cold-mode” theory of galaxy formation was proposed instead, suggesting the cold gas might funnel along filaments into galaxy centers. Stewart and his colleagues set out to test this theory and address the mysteries about how the cold gas gets into galaxies, as well as the rate at which it spirals in.

Since it would take billions of years to watch a galaxy grow, the team simulated the process using supercomputers at JPL; NASA’s Ames Research Center, Moffett Field, Calif.; and the University of California, Irvine. They ran four different simulations of the formation of a galaxy like our Milky Way, starting from just 57 million years after the big bang until present day.

The simulations began with the starting ingredients for galaxies — hydrogen, helium and dark matter — and then let the laws of physics take over to create their galactic masterpieces. Supercomputers are needed due to the enormous number of interactions.

“The simulations are like a gigantic game of chess,” said Alyson Brooks, a co-author of the paper and expert in galaxy simulations at the University of Wisconsin, Madison. “For each point in time, we have to figure out how a given particle — our chess piece — should move based on the positions of all of the other particles. There are tens of millions of particles in the simulation, so figuring out how the gravitational forces affect each particle is time-consuming.”

When the galaxy concoctions were ready, the researchers inspected the data, finding new clues about how cold gas sinks into the galaxy centers. The new results confirm that cold gas flows along filaments and show, for the first time, that the gas is spinning around faster than previously believed. The simulations also revealed that the gas is making its way down to the centers of galaxies more quickly than what occurs in the “hot-mode” of galaxy formation, in about 1 billion years.

“We have found that the filamentary structures that galaxies are built on are key to how they build up over time, by threading gas into them efficiently,” said Leonidas Moustakas, a co-author at JPL.

The researchers looked at dark matter too — an invisible substance making up about 85 percent of matter in the universe. Galaxies form out of lumps of regular matter, so-called baryonic matter that is composed of atoms, and dark matter. The simulations showed that dark matter is also spinning at a faster rate along the filaments, spiraling into the galaxy centers.

The results help answer a riddle in astronomy about galaxies with large extended disks of material spinning around them, far from their centers. Researchers didn’t understand how the outer material could be spinning so fast. The cold-mode allows for this rapid spinning, fitting another jigsaw piece into the puzzle of how galaxies grow.

“The goal of simulating galaxies is to compare them to what telescopes observe and see if we really understand how to build a galaxy,” said Stewart. “It helps us makes sense of the real universe.”

Other authors of the paper are: James Bullock of the University of California, Irvine; Ariyeh Maller of the New York City College of Technology, Brooklyn, N.Y., Jürg Diemand of the University of Zurich, Switzerland; and James Wadsley of the McMaster University, Hamilton, Ontario, Canada.

JPL is managed by the California Institute of Technology in Pasadena for NASA.

This still from a supercomputer simulation reveals that cool gas flows into the centers of galaxies along filaments. Image credit: Video courtesy of the N-Body Shop at University of Washington

This still from a supercomputer simulation reveals that cool gas flows into the centers of galaxies along filaments. Image credit: Video courtesy of the N-Body Shop at University of Washington

Whitney Clavin 818-354-4673
Jet Propulsion Laboratory, Pasadena, Calif.


Published On : The Immortal’s Legend ( The World Of Immortal Thoughts – To Infinity and Beyond )

Read The Blog Introduction here : Introduction

No, Nothing

Life is all about living, sometimes it might turn out the way we wish it should, but most of the times it won’t , because if we were able to predict the future then what would be the fun living it, what would be the use of such life where we knew already what’s gonna happen.
A great man once said – ” If its of your will then its good and if it isnt of your will then its great “.


Success can mean many things to many people, to some it means achieving their goals , to some it means earning a lot of money, to some it means winning over someone or even winning over their fears , but the actual success must be counted in the pleasure we are able to provide others, the memories we gathered to cherish afterwards and to give all our love to others and seeing them happy rather than those material pleasures success must be counted in human sentiments.

Science Pic Of The Day


The Pink See-Through Fantasia is a sea cucumber that can be found in the Celebes Sea, 2,500 meters below the surface.They are propelled by the webbed structures underneath their bodies.

sea cucumber ( the immortals legend)


Irrational Fears

Some phobias or say fears are sometimes actually irrational with no concrete meaning or origin and all we need to do is get rid of them because they would only make our work difficult than make it easier.

irrational-fear ( The Immortals Legend )

Everyone in the world seems to have at least one fear of something whether it is a common one such as of insects or less common like phobias about certain objects or fears of people. This reminds me of the time I went on a trip to the zoo in a large group and nearly no one went into the reptile house and out of the few who went in only 3 came out (including me) and the two people who came out with me were still slightly scared.  I never understand why people can have such a fear of snakes and other reptiles unless they were attacked by them when were young. Perhaps it is just fear of the unknown as most people don’t see snakes every day. But if people didn’t have such a fear of reptiles or amphibians there would be a larger chance to save them from extinction which seems a shame.

In fact there are so many types of phobias you can type it into Google and get a whole list of them and it shows just how many strange fears exist including fear of buttons.  It is strange how people develop fears I guess some people are more prone to specific fears genetically such as shyness which can be passed on. Fears are useful for animals who want to escape from predators but they are usually just a barrier more than anything since fears are almost all irrational.

The only way of getting past fears seems to be to overcome them which is a slow process but of course some people try to overcome fears but they as I have seen before but have failed. The best way of overcoming something is to take it slowly perhaps if someone is scared of a particular object ask them to look at a picture or drawing of it rather than get them to put their hands into to a whole boxful of the object.   People can also overcome fears by writing them down and analysing them or learning about their fear. (For example if they have a fear of bats they could try learning about them). Another way of facing your fear is knowing the origins of it as you will become more aware of the situation you are in when you feel scared.

Posted on : The Immortal’s Legend

Guest Author’s Blog : Thinking of Self Actualization


Immortal’s Quote Of The Day


The best years of your life are the ones in which you decide your problems are your own. You do not blame them on your mother, the ecology, or the president. You realize that you control your own destiny. – Albert Ellis

The Immortal’s Legend


dark side of me

Every person has a dark side that’s deep within him/her which the world doesn’t know about, which remains hidden behind that false smile and happiness that the person shows. The world of one’s pain and sorrow or sometimes a world which provides solace even, or the world where we see our worst fears coming alive and wish them to never come alive in real or the place where our past haunts us and reminds us of the worst times, and gives us strength to move on, and to look to the positivity of life and relive the things we weren’t able to some time.

It Goes On

Sometimes we actually fall less on words when describing our lives and that’s when we say that there isn’t any end to it = it just goes on. Its hard, its happening, its painful , its lovely all we have to do with it is – live it to fullest.
Even when its bad , just like a great person once said – “when you are going through hell, then keep going.”

The Man I Never Knew

We all build up some thinking’s and thoughts for our desires , and for the way we want the world to be ,the way we want people to be. These are all dreams and thoughts about our fantasies – men think about a women who’s perfect for them but whom they haven’t known ever or say haven’t met in person, but they wanna find someone like that and women try finding a man of their desires the one they would call their perfect one.

Thus we all live in this world searching for the things or people we desire but until now haven’t found such things or people ( just to make ourselves feel better and keep searching for the one.)

Stand As One

Life shows us the hard times and even the worst times but all that it provides us with is that courage, that determination , that strength to stand up and fight for our own cause because no one else’s gonna help us anyway we will have to fight our battle ourselves as one.

Another Wandering Soul

between stone and dust
people find their voice;
a whispered word
to ring true
across continents

open eyes
won’t be forced shut
by the sting of tear gas

angry hearts
won’t quench their thirst
in submission to TOMA

stand as one –
your fear of authority
and grasp the strands
of a new Era –
under the world’s watchful eye.

Dedicated to the fighting people in Turkey. Stay strong.
Submitted to dVerse Poets OpenLinkNight – come join us at the bar!

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