Magnetic 'Fingerprint' of the Galaxy May Help Uncover Details of the Big Bang

An international team of astrophysicists has released a map, the first of its kind, of the entire sky that charts the magnetic field shaping the Milky Way galaxy and helps in our understanding of the birth of the universe, or the Big Bang. The details will be released in the journal Astronomy & Astrophysics.

The team created the map using data from the Planck Space Telescope, which since 2009 has charted the Cosmic Microwave Background (CMB) - the light from the Universe a mere 380,000 years after the Big Bang.

The Planck instrument is advantageous in the fact that it can observe the far reaches of time and space, but it's also useful for studying light that's a little closer to home.

Planck detects the light from microscopic dust particles within our galaxy and helps identify the non-random direction in which the light waves vibrate - known as polarization. It is this polarized light that indicates the orientation of the field lines.

"Just as the Earth has a magnetic field, our galaxy has a large-scale magnetic field - albeit 100,000 times weaker than the magnetic field at the Earth's surface," Astrophysicist Douglas Scott explained in a news release. "And just as the Earth's magnetic field generates phenomena such as the aurorae, our galaxy's magnetic field is important for many phenomena within it."

And now," Scott added, "Planck has given us the most detailed picture of it yet."

Dust, even in cosmic proportions, may seem insignificant, but scientists say that it can actually reveal a lot about the universe.

"Dust is often overlooked but it contains the stuff from which terrestrial planets and life form," said Professor Peter Martin of the Canadian Institute for Theoretical Astrophysics, who uses Planck data to study space's dust particles. "So by probing the dust, Planck helps us understand the complex history of the galaxy as well as the life within it."

Once scientists involved in this Planck collaboration release their findings later this year, astronomers should be able to tell the difference between the foreground signal from our Galaxy from the polarized signal from the CMB. And more importantly, will be able to further study the beginnings of our Universe, from when it was just one second old to when the first stars were born several hundred million years later.