National Radio Astronomy Observatory | Very Large Array | 2017 Aug 28
With the help of a gigantic cosmic lens, astronomers have measured the magnetic field of a galaxy nearly five billion light-years away. The achievement is giving them important new clues about a problem at the frontiers of cosmology — the nature and origin of the magnetic fields that play an important role in how galaxies develop over time.
The scientists used the National Science Foundation’s Karl G. Jansky Very Large Array (VLA) to study a star-forming galaxy that lies directly between a more-distant quasar and Earth. The galaxy’s gravity serves as a giant lens, splitting the quasar’s image into two separate images as seen from Earth. Importantly, the radio waves coming from this quasar, nearly 8 billion light-years away, are preferentially aligned, or polarized. ...
Magnetic fields affect radio waves that travel through them. Analysis of the VLA images showed a significant difference between the two gravitationally-lensed images in how the waves’ polarization was changed. That means, the scientists said, that the different regions in the intervening galaxy affected the waves differently. ...
Detection of Magnetic Fields in Galaxy 5 Billion Light-Years Away
Max Planck Institute for Radio Astronomy | 2017 Aug 28
Remote Galaxy Shows We Live in a Magnetic Universe
Dunlop Institute for Astronomy & Astrophysics | University of Toronto | 2017 Aug 28
Detection of microgauss coherent magnetic fields in a galaxy five billion years ago - S. A. Mao et al
- Nature Astronomy (online 28 Aug 2017) DOI: 10.1038/s41550-017-0218-x