GALACTIC COMPASS: A new study clarifies how quickly galaxies built up giant magnetic fields that are still present in today's cosmic denizens such as spiral galaxy M51, shown here in a Hubble Space Telescope image overlaid by radio data documenting its magnetic field.
Image: MPIfR Bonn and Hubble Heritage Team
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Light from distant quasars—early galaxies that shine with tremendous brightness—has given researchers a new clue to the origin of vast magnetic fields studding today's galaxies: They were running strong when the universe was only a third of its present age.
Astronomers had observed that radio emissions from quasars tend to be angled, or polarized, in such a way that powerful magnetic fields must have twisted them. The greater their distance from Earth, the more polarized their light. But researchers didn't know whether the magnetic fields were part of the quasar or were present in galaxies encountered by quasar light as it made its journey to our telescopes.
So a team led by astronomers from the Swiss Federal Institute of Technology (ETH Zurich) scanned more than 70 of those quasars using the European Southern Observatory's Very Large Telescope in Chile to look for signs of galaxies hiding in front of the quasars. Specifically, they checked for a feature called the magnesium(II) absorption line, a reduction in the intensity of light of a certain wavelength, which is a commonly used indicator that gas from a star-forming galaxy has soaked up that light.
The researchers report today in Nature that light from quasars showing the magnesium(II) line was more strongly polarized than light from other quasars in the sample. The interpretation: light did indeed pass through regular galaxies and that it likely acquired its polarization in the process.
They estimated the age of the magnetic galaxies by measuring the red shift of the absorption line—the observed reddening of light that occurs when galaxies move rapidly apart. The typical red shift of the inferred galaxies corresponded to an age of 5.2 billion years, study author Francesco Miniati says. Precision measurements of the cosmic microwave background peg today's universe at 13.7 billion years old.
Miniati says the earliest galaxies did not have magnetic fields. But somehow they became commonplace, perhaps as a result of violent events in quasars that seeded other galaxies with tiny but strong magnetic fields.
Researchers speculate that turbulent matter expanded and strengthened the magnetic fields by pulling them like taffy. "What these observations tell us is that this stretching process took place very rapidly," says Ellen Zweibel, an astrophysicist at the University of Wisconsin–Madison.
She says that incorporating those fields into computer models of star formation might help solve the puzzle of why stars that formed in the past five billion years or so were typically about the size of the sun—smaller than earlier ones. Galactic magnetic fields are thought to influence the size of stars by making them spin slower.
The observations "tell us that magnetic fields really were there in these early times," she says, "and you have to include them in the models."
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7 Comments
Add CommentWhat is the evidence for the proposition that "early galaxies did not have magnetic fields"? Anyone?
Reply | Report Abuse | Link to thisThe fact that the source of the quasars' (early galaxies') supposed magnetic fields were really the younger galaxies sitting between us and them in our line of sight. They must have been able to account for all the magnetism they detected as within the newer galaxies, I guess.
Reply | Report Abuse | Link to thisMs Ellen Zweibel and many scientists wonder why the stars formed some 5 billion years ago are of similar size of our sun -small-, a big cosmic puzzle. Well, how about that "there is not enough raw material up there?"
Reply | Report Abuse | Link to thisVal Ladra
Ms Ellen Zweibel and many scientists wonder why the stars born after 5 billion years or so are of the small size as our own sun, but maybe "there is not enough matter -rough material- up there"...
Reply | Report Abuse | Link to thisVal Ladra
About the Aphophis asteroid.
Reply | Report Abuse | Link to thisScience people has discovered an asteroid that they baptized APHOPHIS that vertiginous going to earth, there is the possibility that in the year 2029 he will hit the earth, which will have dramatic consequences for humanity, that situation could be repeated in the year 2036, when he will return.
Its possible to avoid this collision?
All scientists have imagined and pictures in different scenarios how to avoid such a collision.
Whether launching a missile with or without human crew to place on this asteroid a nuclear load, or of sending nuclear missiles with nuclear charges to hit and destroy the asteroid and many others.
In fact, in my opinion, there is a way much simpler, cheaper and even more useful.
In the present everything is based on universal gravity theory, formulated by Chauny Newton, that theory says:
Gravitation attraction between two bodies is a function of the mass, respectively directly proportional to the product and two mass and gravitational constant inversely proportional with the square of the distance between the two bodies, reducing the mass of the two bodies, the sun and the planet at two collinear points ,
Accordingly:
F = m M g / R� (1)
Where:
F = force of attraction
M = mass of the central star
m = mass of the body which gravitate
g = gravitational constant
R = range (distance between central planet and the one which gravitate)
But if instead of the classic formula, in fact correct, we will utilize, the formula:
F = r�V�G / Rg (2)
Where:
F = Force attraction
V = speed revolution
r = radius of the planet which gravitate
G = Gravitational acceleration of the body which gravitate
R = range (distance between the central planet and the one which gravitate)
g = gravitational constant
From this formula we can observe that the attraction between the mass of the two planet is directly proportional to body size (radius) and speed revolution, and vice versa proportional product with the distance between the bodies and two gravitational constant.
As is well known, the movement of the planet on its orbit is not linear but involved, and an oscillating movement (nearby, away from the sun) on orbit.
This movement is due oscillating just variation relief planet. Departure or approaching to the sun being based on the radius of the planet at a time &. Thus if the planet at 12.00 (astronomical time) have a high formation of relief, then the planet will be departure from the sun. If relief is low altitude, at the same astronomical time, (12.00), the planet will be approaching to the sun. That is valid in case of relief due to construction, more or less high.
This can be easily checked if each astronomical observatory will finish the distance to the sun at the time of astronomical time 12.00.
It is known also as artificial satellites that are freely rotating around the earth easily follow the forms of relief.
You can verify the fact that orbit of our planet is in the XX century very much changed, as opposed to the same orbit but in the nineteenth century, and that is the result of the increasing rhythm from construction, in the XX century.
Conclusion:
After determining the exact place of collision, the timing and trajectory of the asteroid as may be established, where punctual to raise a building, even the pyramidal form (pyramidal form allow a more smooth motion of the planet) or any other form, a well-determined height, or on the contrary creating a huge hole, which allows the earth to move out from asteroid trajectory.
In this way we can avoid any collision with any planet, bigger, coming from space, as we trick this asteroid, hiding the ball (the planet)
In fact I believe that this method of moving the path of an earth asteroid has been used thousands of years ago. I believe that the Keopss pyramid and the giant statues of Easter island had exactly the same purpose.
About the Aphophis asteroid.
Reply | Report Abuse | Link to thisScience people has discovered an asteroid that they baptized APHOPHIS that vertiginous going to earth, there is the possibility that in the year 2029 he will hit the earth, which will have dramatic consequences for humanity, that situation could be repeated in the year 2036, when he will return.
It’s possible to avoid this collision?
All scientists have imagined and pictures in different scenarios how to avoid such a collision.
Whether launching a missile with or without human crew to place on this asteroid a nuclear load, or of sending nuclear missiles with nuclear charges to hit and destroy the asteroid and many others.
In fact, in my opinion, there is a way much simpler, cheaper and even more useful.
In the present everything is based on universal gravity theory, formulated by Chauny Newton, that theory says:
Gravitation attraction between two bodies is a function of the mass, respectively directly proportional to the product and two mass and gravitational constant inversely proportional with the square of the distance between the two bodies, reducing the mass of the two bodies, the sun and the planet at two collinear points ,
Accordingly:
F = m M g / R² (1)
Where:
F = force of attraction
M = mass of the central star
m = mass of the body which gravitate
g = gravitational constant
R = range (distance between central planet and the one which gravitate)
But if instead of the classic formula, in fact correct, we will utilize, the formula:
F = r²V²G / Rg (2)
Where:
F = Force attraction
V = speed revolution
r = radius of the planet which gravitate
G = Gravitational acceleration of the body which gravitate
R = range (distance between the central planet and the one which gravitate)
g = gravitational constant
From this formula we can observe that the attraction between the mass of the two planet is directly proportional to body size (radius) and speed revolution, and vice versa proportional product with the distance between the bodies and two gravitational constant.
As is well known, the movement of the planet on its orbit is not linear but involved, and an oscillating movement (nearby, away from the sun) on orbit.
This movement is due oscillating just variation relief planet. Departure or approaching to the sun being based on the radius of the planet at a time …. Thus if the planet at 12.00 (astronomical time) have a high formation of relief, then the planet will be departure from the sun. If relief is low altitude, at the same astronomical time, (12.00), the planet will be approaching to the sun. That is valid in case of relief due to construction, more or less high.
This can be easily checked if each astronomical observatory will finish the distance to the sun at the time of astronomical time 12.00.
It is known also as artificial satellites that are freely rotating around the earth easily follow the forms of relief.
You can verify the fact that orbit of our planet is in the XX century –very much changed, as opposed to the same orbit but in the nineteenth century, and that is the result of the increasing rhythm from construction, in the XX century.
Conclusion:
After determining the exact place of collision, the timing and trajectory of the asteroid as may be established, where punctual to raise a building, even the pyramidal form (pyramidal form allow a more smooth motion of the planet) or any other form, a well-determined height, or on the contrary creating a huge hole, which allows the earth to move out from asteroid trajectory.
In this way we can avoid any collision with any planet, bigger, coming from space, as we trick this asteroid, hiding the ball (the planet)
In fact I believe that this method of moving the path of an earth asteroid has been used thousands of years ago. I believe that the Keops’s pyramid and the giant statues of Easter island had exactly the same purpose.
If so, that result seems counter-intuitive. What about these early galaxies accounts for their lack of a magnetic field? The sun has an enormous magnetic field. Why wouldn't stars in early galaxies likewise have magnetic fields? And how can any galaxy consisting of millions of suns with magnetic fields spinning around a denser core of suns with magnetic fields ever NOT have a magnetic field? Doesn't make sense to me. Unless someone can explain the result, I suspect instrumentation or calculation error accounts for the apparent lack of magnetic field in early galaxies.
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