What does the X-ray Universe look like?


Only the hottest cosmological objects and the most energetic events generate X-rays. Studying them teaches astronomers about the violent Universe, where stars explode, black holes devour matter and galaxies collide.

Hot halo: X-rays from extremely hot gas and from neutron stars and black holes in the Antennae Galaxies are colour-coded blue in this composite image.
Credit: NASA, ESA, SAO, CXC, JPL-Caltech, and STScI.

The hottest objects and the most violent events in the Universe produce high-energy X-rays: solar flares, neutron stars, cosmic shock waves, extremely hot gas in galaxy clusters, colliding galaxies and matter spiralling into black holes. The human eye cannot see X-rays. In fact, your retina would be destroyed by this energetic cosmic radiation. Astronomers use representative colours to create images of the X-ray Universe, based on observations by Earth-orbiting space telescopes.

Our ears cannot hear the high pitch of a dog whistle. In the same way, our eyes cannot see X-rays coming from space. The pictures here show what you would see if you had X-ray vision.