The European Southern Observatory (ESO) has released an image of the so-called Einstein Cross, taken with the Very Large Telescope (VLT) in Chile, which resembles a flower with blue petals.
These “petals” are images of a distant galaxy hidden behind the orange galaxy in the center.
What allows us to detect the light from this hidden object is a phenomenon in which the galaxy at the center acts as a gravitational lens, bending the light emitted by the distant galaxy around it, ESO explains in a statement.
As a result, we see several distorted and enlarged images of the distant galaxy. In the configuration of these two specific galaxies, the hidden galaxy appears as four images around the central galaxy, which acts as a “lens” and forms a cross-shaped (or flower-shaped) pattern called the Einstein Cross.
Gravitational lensing therefore allows us to discover hidden galaxies that would otherwise be invisible to us.
Observations of this system were made using the Multi Unit Spectroscopic Explorer MUSE instrument installed at the ESO VLT in Chile. MUSE divides the light coming from any point within the observation area into a rainbow or spectrum, providing the astronomical community with a wealth of information about the objects present in the field of view.
The results of these observations, presented in a new paper led by Aleksandar Cikota of the Gemini Observatory (Chile), show that the distant galaxy is forming stars at high speeds. Because the light left the galaxy when the universe was about 20% of its current age, its study provides clues about how galaxies formed in the early universe, ESO reports in a statement.