Researchers say they've managed to create the first full magnetic fingerprint of our home Milky Way galaxy, which should help astronomers better understand star formation within it.
The fingerprint was compiled from data gathered by the European Space Agency's Planck space telescope, a mission with significant NASA involvement, after it completed the first complete-sky observation of polarized light emitted throughout the galaxy by interstellar dust and gas.
That light emitted by gas, dust and stars carries significant information about what has happened to it on its way to us as it passes through the galaxy's magnetic fields, information astronomers can use in studying the Milky Way.
Scientists have been poring over the data since Planck finished its survey in 2013, looking for signs of the origin and formation of galaxies and stars.
"This is the best picture we've ever had of the magnetic field in the Milky Way over such a large part of the sky," said Charles Lawrence, Planck scientist NASA's Jet Propulsion Laboratory in Pasadena, California.
In the Planck "fingerprint" image darker regions represent stronger emissions of polarized light and the image also shows that in some parts of the galactic magnetic field there is large-scale organization.
The darkest and therefore strongest region, spanning the center of the image is aligned with the plane of the galaxy, while twisted features seen below and above the galactic plane, where the local magnetic field shows disorganization, reveals variations in the polarization direction.
"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," research team member Douglas Scott, an astrophysicist at the University of British Columbia, says. "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."
Many of those phenomena are revealed by studying the galaxy's dust and its effect on polarized light.
Though spread so thinly through the galaxy it seems like it is only a minor component of it, dust plays a large part in the formation of stars and their protoplanetary disks, the researchers say.
"Dust is often overlooked but it contains the stuff from which terrestrial planets and life forms," Scott says.
