VLA Reveals Distant Galaxy’s Magnetic Field
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.