Centaurus A

Centaurus A, also known as NGC 5128 is one of the closest radio galaxies to Earth, so its active galactic nucleus has been extensively studied by professional astronomers.

The galaxy is also the fifth-brightest in the sky. The centre of the galaxy contains a supermassive black hole with a mass of 55 million solar masses, which ejects a relativistic jet that is responsible for emissions in the X-ray and radio wavelengths.

Like other starburst galaxies, a collision is suspected to be responsible for the intense burst of star formation. Models have suggested that Centaurus A was a large elliptical galaxy that collided and merged with a smaller spiral galaxy.