| 16th of October 2015 |
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| CHANG-ES astronomers probe the spectacular halos of galaxies |
| by Jayanne English (University of Manitoba, Canada) |
| The CHANG-ES collaboration has recently made
their first batch of specialized Very Large Array maps for 35 edge-on galaxies
available to other researchers at
http://queensu.ca/changes. Led by Judith Irwin (Queen's U., Canada), the
team studies the radio halo produced by fast-moving particles in a galaxy's
magnetic field. In a
companion paper,
led by Theresa Weigert, they present a
'median radio halo'. That is, to see how extensive a "typical" halo
is, Irwin scaled radio continuum observations of 30 of their target galaxies
and Jayanne English (U. Manitoba) combined them using a median algorithm. The
individual halos were acquired at 20 cm using the Very Large Array (VLA) in
the D configuration. - A press release is available at NRAO. In the composite image presented here, the large, grey-blue area is a single image of this median radio halo. As a proxy for a generic spiral galaxy disk, at the center is a visible-light image of one of the target galaxies -- NGC 5775. Made from data acquired in 2 filters using the Hubble Space Telescope, this visible-light image shows only the inner part of the galaxy's star-forming region, outer portions of which extend horizontally into the area of the radio halo. Image credit: Jayanne English (U. Manitoba), with support from Judith Irwin and Theresa Wiegert (Queen's U.) for the CHANG-ES consortium; NRAO/AUI/NSF; NASA/STScI |