A pair of galaxies make up the eyes of the universe

A pair of galaxies whose cores look similar, but in the very large telescope the scientists manage to find the differences between them

The Very Large Telescope of the European Southern Observatory (ESO) captured a spectacular image of a pair of beautiful but also strange galaxies known as the "Eyes". The largest of them, NGC 4438 was once a spiral galaxy but it changed as a result of a collision with other galaxies a few hundred million years ago. This image is the first product of the "Cosmic Jewels" program - an ESO initiative in which observing time is allocated for educational purposes.

The "eyes" are about 50 million light-years away in the direction of the Virgo cluster and are about a hundred thousand light-years apart. The nickname derives from the apparent similarity between the cores of the two galaxies - which resemble a pair of eyes glowing in the dark when viewed through medium-sized telescopes.

However, although the centers of the two galaxies look similar, their edges could not be more different. The galaxy on the lower right, NGC 4435, is compact and appears almost free of gas and dust. In contrast, in the large galaxy on the upper left (NGC 4438) a trail of gas hides it in the visible light just below the nucleus, you can see young stars to the left of the center and gas that extends at least to the edge of the image.

The contents of NGC 4438 were pulled out of it by a violent process: a collision with another galaxy. This collision destroyed its spiral galaxy structure, something that may also happen to the Milky Way when it collides with the neighboring galaxy Andromeda in about 3-4 billion years.

NGC 4435 could be to blame, some astronomers believe the damage was done to NGC 4438 after the two galaxies came within 16 light years of each other, which happened about 100 million years ago. However, while the larger galaxy was damaged, the smaller one was significantly affected by the collision. Gravitational waves from the collision are likely responsible for tearing apart the contents of NGC 4438 and reducing the mass of NGC 4435 and removing most of its gas and dust.

Another possibility is that the giant elliptical galaxy M86, slightly out of sight and not visible in this image, is responsible for the damage done to NGC 4438. Recent observations have shown that jets of ionized gas connect the two large galaxies, indicating that they may have collided in the past.
The three galaxies - the eyes and M86 belong to the Virgo cluster, an area rich in galaxies. In such a dense neighborhood collisions between galaxies are relatively frequent, so NGC 4438 may have suffered collisions with both NGC 4435 and M86.

The Cosmic Jewel Project utilizes the telescope's time when visibility is insufficient for scientific observations, but can be used to photograph objects of interest in visible light. The data was also available to professional astronomers in the ESO archive.

In this case, although there were few clouds, the atmosphere was stable, which made it possible to capture sharp details using the Very Large Telescope's FORS2 instrument.

The light passed through two filters red (the red colors in the picture) and green-yellow (the blue colors in the picture), and the exposure times were 1800 seconds and 1980 seconds. FORS2 is a visible light and near ultraviolet camera and low dispersion spectrograph.