A team of experts at Keele University has created the largest map to date of distant galaxies obscured by the Magellanic Cloud.
A section of the Small Magellanic Cloud captured by the VISTA telescope, with distant galaxies circled in green. Image: ESO/VISTA Magellanic Clouds Survey
Astronomers have mapped a record-breaking one million distant galaxies obscured by the Magellanic Cloud — a neighboring group of galaxies to the Milky Way, as reported by Space on July 29.
The Magellanic Clouds are dwarf galaxies with unusual shapes that can be seen with the naked eye in the Southern Hemisphere sky. However, their brightness and large scale have blocked scientists’ views of even more distant galaxies. Consequently, when observing billions of galaxies in the universe, they often avoid this region of the sky.
Jessica Craig, an astronomer at Keele University in the UK, and her colleagues addressed this issue by capturing high-resolution images of the Magellanic Cloud that allowed them to see through the gaps between the stars in these galaxies. To achieve this, the research team utilized the Visible and Infrared Survey Telescope for Astronomy (VISTA) at the Paranal Observatory in Chile.
The particularly distant hidden galaxies are especially difficult to observe because they appear fainter and redder due to dust in the Magellanic Cloud. To counter this effect, the research team employed the GASKAP radio telescope, which can see through the dust layer between Earth and the distant galaxies.
Due to the overwhelming number of light sources in photographs of the Magellanic Cloud, the human eye cannot distinguish between distant galaxies and nearby objects. However, as stars shift positions while the distant galaxies remain stationary, the research team was able to utilize data from the Gaia Observatory to accurately classify each light source. They then applied another technique based on light wavelengths to more reliably distinguish the distant galaxies from the nearby stars.
Ultimately, the team of astronomers employed machine learning and artificial intelligence (AI) to organize the galaxies and create a 3D map of approximately one million hidden galaxies. Craig presented these new findings at the National Astronomy Meeting held at the University of Warwick in mid-July.
