Black Hole
A black hole is an astronomical object whose gravity is so strong that nothing—even light—can escape from within its event horizon. It forms when a massive star’s core collapses or through other processes, and may have an accretion disk of infalling matter that emits radiation. Supermassive black holes at galaxy centers influence stellar orbits, and mergers produce gravitational waves.
Source: nasa.gov
APODs including "Black Hole"
The Most Distant X-Ray Jet
28/11/2003
A false-color x-ray image inset at upper left reveals emission from a cosmic jet of high-energy particles, 100,000 light-years in length, emerging from quasar GB1508+5714. An estimated 12 billion (12,000,000,000) light-years away, this appears to be the most distant energetic jet in the known Universe. Astrophysical jets of many sizes seem to be produced in a range of environments where significant accretion, or infalling matter is thought to arrange itself in a disk, from contracting star-forming clouds to supermassive black holes in active galactic nuclei. Here, as depicted in the illustration, the accretion disk is thought to surround a supermassive black hole, accelerating particles to near the speed of light in two jets at right angles to the disk itself. In the case of this quasar, the jet tilted towards us is visible in x-rays as the particles collide with low energy photons from the cosmic background radiation. The collisions boost the photons to higher x-ray energies and scatter some of them in our direction.