Scientists have found more than 800 galaxies hiding behind our Milky Way. Using the CSIRO’s Parkes radio telescope in Australia, the international team of scientists, for the first time, were able to see through the gas and dust of the Milky Way.
Lead author Professor Lister Staveley-Smith, from the University of Western Australia node of the International Center for Radio Astronomy Research (ICRAR), said in a statement that the team had found 883 galaxies, a third of which had never been seen before:
“The Milky Way is very beautiful of course, and it’s very interesting to study our own galaxy, but it completely blocks out the view of the more distant galaxies behind it.”
The new galaxies are just 250 million light years from Earth, which in astronomical terms is very close. They have remained hidden from view because of the brightness and the concentration of stars within the Milky Way.
Below is an annotated animation showing the location of the galaxies discovered in the “Zone of Avoidance.” Until now this region of space has remained hidden from view because of the gas and dust of the Milky Way, which blocks light at optical wavelengths from reaching telescopes on Earth.
By using CSIRO’s Parkes radio telescope to detect radio waves that can travel through our galaxy’s gas and dust, hundreds of new galaxies have been found in the region of space known to astronomers as the “Zone of Avoidance.”
This animation has been created using the actual positional data of the new galaxies, and randomly populating the region with galaxies of different sizes, types, and colors. Credit: ICRAR. Music by Holly Broadbent:
Astronomer Professor Renée Kraan-Korteweg, from the University of Cape Town, and part of the international team, said that astronomers have been trying to map the galaxy distribution hidden behind the Milky Way for decades:
“We’ve used a range of techniques, but only radio observations have really succeeded in allowing us to see through the thickest foreground layer of dust and stars.
“An average galaxy contains 100 billion stars, so finding hundreds of new galaxies hidden behind the Milky Way points to a lot of mass we didn’t know about until now.”
The new research has identified several new structures that could help to explain the movement of the Milky Way, which includes three galaxy concentrations (named NW1, NW2, and NW3) and two new clusters (named CW1 and CW2).
Below is a visualisation showing the coordinates of the new “hidden galaxies.” At the center is Earth. Blue represents galaxies found in other surveys, and other colors show the locations of the new galaxies. Credit: ICRAR:
It is hoped that with further study the discoveries will help explain anomalies within the universal expansion of the cosmos, like the “Great Attractor.” The “Great Attractor” is pulling the Milky Way and hundreds of thousands of other galaxies toward it with huge gravitational force.
Professor Staveley-Smith who was part of the international team said scientists have been working on the mysterious “Great Attractor” since major deviations from universal expansion were first discovered in the 1970s and 1980s.
“We don’t actually understand what’s causing this gravitational acceleration on the Milky Way, or where it’s coming from.
“We know that in this region there are a few very large collections of galaxies we call clusters or superclusters, and our whole Milky Way is moving toward them at more than two million kilometers per hour.”
The Australian radio telescope, which was first made famous when it assisted with the moon landings, had been fitted with a 8.3 inches (21-cm) multibeam receiver, which made it possible to see the previously unexplored region of space.
Dr. Bärbel Koribalski from CSIRO Astronomy and Space Science said the new innovative technologies on the Parkes Radio telescope had made it possible to survey large areas of the sky very quickly:
“With the 21-cm multibeam receiver on Parkes we’re able to map the sky 13 times faster than we could before, and make new discoveries at a much greater rate.”
The study was published in The Astronomical Journal, and involved researchers from Australia, South Africa, the U.S., and the Netherlands.