Scientists from the Scuola Internazionale Superiore di Studi Avanzati (Sissa) in Italy have finally caught a glimpse of the elusive black galaxy known as the “invisible galaxy”. Despite being sought after for years by astronomers, the ancient galaxy eluded detection by even our most advanced telescopes. However, with the help of the Atacama Large Millimeter/Submillimeter Array (ALMA), the team of researchers were able to fully characterize the properties of this galaxy.
How the Invisible Galaxy was Discovered
The team of researchers revealed that the invisible galaxy is compact and contains large quantities of interstellar dust, making it a young galaxy that is forming stars at approximately 1000 times the rate of the Milky Way. The massive presence of interstellar dust is what makes this galaxy difficult to observe with optical instruments, as it intercepts visible light from young stars and re-emits it at greater wavelengths.
To overcome this challenge, the team used a technique that involves using large celestial bodies as a kind of cosmic lens, which makes the “background” galaxies appear larger and brighter. Over the past decade, many observation programs have been carried out using this approach, leading to the discovery of about a hundred galaxies so far.
The Significance of the Discovery
“Very distant galaxies are real mines of information about the past and future evolution of our universe,” says First Author Marika Giulietti. The study of these galaxies is challenging, as they are very compact and receive weak light from a distance. However, understanding these galaxies can help us gain insights into the formation and evolution of our universe.
The discovery of the invisible galaxy is a significant step forward in our understanding of the universe. With powerful interferometers in the millimeter and radio wavebands, it is possible to study these distant galaxies and learn more about their properties and evolution.