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News Release - Queen's University researcher uncovers unique movement in distant galaxies

Tuesday, November 26, 2019

(November 2019) Queen’s University Professor Judith Irwin, along with her Continuum Halos in Nearby Galaxies -- an EVLA Survey (CHANG-ES) project group, have discovered the unique orientation of magnetic fields never seen before in any galaxy halo (the gaseous region around a galaxy).  These magnetic fields reverse direction with a systematic pattern which is likely connected to spiral structure in the disk.

The project is an international project involving a survey of galaxies that are edge-on to the line of sight, using the Expanded Very Large Array (EVLA)  telescope. Dr. Irwin and her team have observed 35 galaxies. The choice of galaxies with an edge-on orientation allows them to see into the halo.

The galaxy with the unusual magnetic fields was NGC 4631. It’s 25 million light-years from Earth in the constellation Canes Venatici. It is about 80 million light-years across, slightly smaller than our own Milky Way. NGC 4631 was the focus of the PhD Thesis of Carolina Mora-Partiarroyo of the Max-Planck Instutut fur Radioastronomie in Bonn Germany.

Dr. Irwin worked with Professor Emeritus Richard Henriksen and their joint graduate student Alex Woodfinden. The theoretical work was done at Queen's. 


“The discovery is significant because it points to the complexity of magnetic fields in galaxies and their importance in galaxy outflows.  We see gas and cosmic rays leaving galaxies as winds, possibly blowing into the intergalactic medium.  The same thing should be occurring in our own Milky Way although it would be hard to see it from our vantage point inside.  When gaseous material leaves the galaxy disk, there can be important consequences for internal star formation and the energy budget.”

- Judith Irwin, Physics, Engineering Physics and Astronomy


Learn more about CHANG-ES.

Judith Irwin’s website.

National Radio Astronomy Observatory


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