Department of Physics, Engineering Physics & Astronomy

Department of Physics, Engineering Physics & Astronomy
Department of Physics, Engineering Physics & Astronomy

Researchers discover distant galactic halos

Posted On: October 14, 2015

Edge-on galaxies, when seen with the naked eye, look like a line in the sky. By using a more powerful and upgraded Very Large Array telescope, unique properties of spiral galaxies are revealed.

Spiral galaxies, like the Milky Way, have the vast majority of their stars, gas, and dust in a flat, rotating disk with spiral arms. Most of the light and radio waves seen with telescopes come from objects in that disk. Learning about the environment above and below such disks has been difficult.

An international team of astronomers including lead author and Queen’s postdoctoral student Dr. Theresa Wiegert and Dr. Judith Irwin from the Department of Physics, Engineering Physics and Astronomy, used the Karl G. Jansky Very Large Array (VLA) to study 35 edge-on spiral galaxies at distances from 11 million to 137 million light-years from Earth.

Professor Irwin states,

We knew before that some halos existed, but, using the full power of the upgraded VLA and the full power of some advanced image-processing techniques, we found that these halos are much more common among spiral galaxies than we had realized.

Dr. Wiegert states,

Studying these halos with radio telescopes can give us valuable information about a wide range of phenomena, including the rate of star formation within the disk, the winds from exploding stars, and the nature and origin of the galaxies’ magnetic fields.

VLA images are available to other researchers to allow them to do their own analyses to explore other aspects of the halos including what they reveal about the evolution of galaxies. The data release can be found on the group's web site at CHANG-ES (Continuum Halos in Nearby Galaxies - an EVLA Survey).

The results of the CHANG-ES project can be found in the publication of Astronomical Journal.

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