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Today @SOFIAtelescope shares our image of the magnetic field that hides deep into the disk of the Whirlpool Galaxy
In this thread I will explain what does this image mean, why it looks so beautiful and why we needed to put a telescope in the tail of a 747 to make it. Let's go! https://twitter.com/SOFIAtelescope/status/1349818574748209154
In this thread I will explain what does this image mean, why it looks so beautiful and why we needed to put a telescope in the tail of a 747 to make it. Let's go! https://twitter.com/SOFIAtelescope/status/1349818574748209154
The idea that I want you all to go with is that galaxies are giant self-gravitating space magnets. The magnetic field lines flow with the gas between stars. These lines stretch twist and squeeze as they rotate around the galactic center, resulting in Van Gogh-like spiral patterns
But why is this important? It turns out that magnetic fields help to create new stars. Stars are made of gas, and this gas must compress and collapse into burning plasma-balls. Gravity makes the clouds smaller but as they compress they rotate faster and faster..(credit Bate+2002)
The problem is that these almost-born-stars need to *brake* a little bit, otherwise they would have too much angular momentum and they would rip apart, like that poor astronaut in "Mission to Mars".
Note to future astronaut applicants: That cannot happen in Mars. Don't worry.
Note to future astronaut applicants: That cannot happen in Mars. Don't worry.
Magnetic fields also shape the dense nebulae of gas where stars are born. One beautiful example is the Orion nebula, where we can see these dense filamentary clouds of gas condensing in what will be newborn stars. Like storm clouds, they are about to rain... stars. Credit:ESO/VLT
If we look again to the Orion nebula, but this time with @SOFIAtelescope, we can detect the magnetic field lines that shape these gorgeous stellar nursery.
Try to think on these stripe patterns like if they were those lines often drawn when you want to explain a magnet. Another example would be the Sun. You can also see magnetic lines on these amazing coronal loops on the surface of the Sun, for example!
Okay, magnetic fields make galaxies full of stars, beautiful and complicated. I want one of these pictures for my refrigerator. How do we detect them?
(Bonus: look how amazing the magnetic field in the Milky Way's supermassive black hole looks like
)
https://www.sofia.usra.edu/multimedia/about-sofia/sofia-mobile-information/magnetic-field-may-be-keeping-milky-way%E2%80%99s-black-hole
(Bonus: look how amazing the magnetic field in the Milky Way's supermassive black hole looks like
)https://www.sofia.usra.edu/multimedia/about-sofia/sofia-mobile-information/magnetic-field-may-be-keeping-milky-way%E2%80%99s-black-hole
Well, it turns out that magnetic fields polarize the light that come from galaxies.
This means that if we measure the direction in which the light of a galaxy "vibrates", we are measuring the direction of the magnetic field in an object trillions of kilometres away!
This means that if we measure the direction in which the light of a galaxy "vibrates", we are measuring the direction of the magnetic field in an object trillions of kilometres away!
Wait what? My sun-glasses are polarized. Can I measure magnetic fields with them?
Well you can measure the angle of polarization, for sure! DYK that light from your smartphone is polarized? Find some polarized sun-glasses and rotate them for a surprise!
Well you can measure the angle of polarization, for sure! DYK that light from your smartphone is polarized? Find some polarized sun-glasses and rotate them for a surprise!
Unfortunately, to measure the magnetic field of galaxies you might need a powerful telescope and a way to escape Earth's atmosphere
Turns out that the gas clouds where stars are born are only detectable in far-infrared. This light is a weird mix between microwaves and infrared.
Turns out that the gas clouds where stars are born are only detectable in far-infrared. This light is a weird mix between microwaves and infrared.
The problem is that our atmosphere is opaque to this light. It absorbs far-infrared before the it can reach the ground. So, we must get far higher that any mountain on Earth to detect something! It was too experimental to launch a satellite, so we needed a new class of telescope.
At some point the smart people at NASA thought: What if we buy a Boeing 747, saw a hole on the tail, put a telescope inside, and just fly it above the atmosphere?
Well, so they did. And the @SOFIAtelescope program was born.
Well, so they did. And the @SOFIAtelescope program was born.
A telescope capable of flying to any location in the world, get high above the clouds to work like a space telescope and land everyday to bring new data and try new things.
They equipped her with the best polarimeter and stabilizer that you can imagine, everything we needed.
They equipped her with the best polarimeter and stabilizer that you can imagine, everything we needed.
During 7 flights, SOFIA observed the far-infrared polarized light of the M51 galaxy, allowing us to calculate the angle of the magnetic field, and study its beautiful spiral structure.
The only thing left is to land at @NASAAmes with the amazing people at @SOFIAtelescope and @USRAedu, so they can train and teach you everything step by step.
And have the luck to work with @LeslieWProudfit, who made this lovely image mixing @NASAHubble and our data! Thank you!
And have the luck to work with @LeslieWProudfit, who made this lovely image mixing @NASAHubble and our data! Thank you!
