Using the National Science Foundation's Karl G. Jansky Very Large Array (VLA), astronomers studying gas halos in nearby galaxies were amazed when they found out that one of the subjects they were monitoring was actually two galaxies, almost perfectly overlaying each other, with one covering the other from clearer vision from previous images generated.
The galaxy, called UGC 10288, is a spiral galaxy that's more than 100 million light-years away. In 2011 and 2012, multiple VLA observations produced high-quality radio-telescope images of the galaxy, and further studies have now revealed that a more distant galaxy is beyond the UGC 10288. The two had been blended together in previous images, Phys Org reports.
It has been difficult to study the environment below and above spiral galaxies like our own Milky Way because the stars, gas, and dust are moving in a flat, rotating disk with spiral arms.
In order to completely investigate the environment from these gas halos, the "Continuum Halos in Nearby Galaxies, an EVLA Survey" (CHANG-ES) project, brought together scientists from all over the globe with the goal of understanding the overall relationship, occurrence and origin of radio halos, to probe the disk-halo interface, and to study in-disk emission as well as their magnetic fields and the cosmic rays illuminating these fields, Astronomy reports.
"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," said Theresa Wiegert of Queen's University, according to the press release from NRAO.
Wiegert is the lead author of a paper in the Astronomical Journal reporting the team's findings and analysis of data from all 35 galaxies included in the study.