Venice is definitely a city for one's bucket list

Yes, there is a galactic cannibal in our universe, and it refers to the phenomenon where one galaxy collides with and absorbs another galaxy, a process known as galactic cannibalism. 

One of the most famous examples of this occurs in our own cosmic neighborhood: the Milky Way galaxy is on a collision course with its neighboring galaxy, the Andromeda galaxy (M31), and it's believed to have already devoured smaller galaxies in the past.

What is Galactic Cannibalism?

• Galactic cannibalism happens when a larger galaxy gravitationally attracts a smaller galaxy and ultimately absorbs it. During the collision and merger process, the smaller galaxy's stars, gas, and dust are often consumed by the larger galaxy. This can lead to the growth of the larger galaxy, sometimes significantly increasing its size and altering its structure.

The Milky Way: A Galactic Cannibal

• Milky Way’s Past: The Milky Way galaxy has a long history of galactic cannibalism. It is believed to have absorbed smaller galaxies in the past. One example is the Sagittarius Dwarf Galaxy, which is being pulled apart by the Milky Way's gravity as it gets consumed.

• Future Collision with Andromeda: The Milky Way is on a collision course with the Andromeda galaxy, which is the largest galaxy in the Local Group of galaxies. The two galaxies are expected to collide in about 4.5 billion years, merging to form a larger elliptical galaxy. During this process, smaller galaxies around them might also be absorbed.

How Does Galactic Cannibalism Work?

1. Gravitational Pull: The larger galaxy exerts a stronger gravitational force on the smaller galaxy, pulling it in.
2. Collision: As the two galaxies collide, the interstellar gas and dust within them interact, triggering bursts of star formation in some areas.
3. Absorption: Over time, the smaller galaxy's stars and matter are absorbed into the larger galaxy. The smaller galaxy may eventually lose its distinct shape and become part of the larger galaxy's structure.

Impact on the Galaxies

• Star Formation: In the process of galactic cannibalism, the merger can trigger a new wave of star formation, as gas clouds collide and compress, sparking new stars to form.
• Shape and Structure: The larger galaxy often undergoes significant changes in shape and structure, potentially transforming from a spiral galaxy to an elliptical galaxy due to the mixing of the two galactic disks.

• Supermassive Black Hole Growth: The supermassive black holes at the centers of these galaxies may also merge, forming an even more massive black hole at the center of the newly formed galaxy.

Other Examples of Galactic Cannibalism

• M87: The giant elliptical galaxy M87, located in the Virgo Cluster, is another example of a "galactic cannibal." It has likely consumed many smaller galaxies and now has an exceptionally large supermassive black hole at its center.

• The Milky Way’s Past Cannibalism: The Milky Way has absorbed several smaller galaxies over billions of years, contributing to its growth. For instance, the Canis Major Dwarf Galaxy is one of the smallest and closest galaxies that the Milky Way is currently consuming.

"Galactic cannibals" are not a rare occurrence in the universe, and our Milky Way is an example of a galaxy that has both devoured smaller galaxies and is heading toward a future collision with the Andromeda galaxy. These cosmic events have profound effects on the structure and evolution of galaxies, leading to the formation of larger and more complex systems over time.