Black Holes

While most stars end up as white dwarfs or neutron stars, black holes are the last evolutionary stage in the lifetimes of enormous stars that had been at least 10 or 15 times as massive as our own sun.

When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

In younger stars, nuclear fusion creates energy and a constant outward pressure that exists in balance with the inward pull of gravity caused by the star's own mass. But in the dead remnants of a massive supernova, no force opposes gravity—so the star begins to collapse in upon itself.

viMory:   detonate   爆炸      cataclysms   大变动                                                                                    

An artist's rendering, made using data collected by the orbiting Chandra X-ray Observatory, shows a quasar galaxy with a jet of high-energy particles extending more than 100,000 light-years from the supermassive black hole at its center. The object, located 12 billion light-years from Earth, is the most distant such jet ever detected. These quasar jets are formed when electrons emitted from a black hole impact with cosmic background radiation left by the big bang, giving astronomers clues about the conditions in the early universe.

viMory:  rendering  描写        quasar   类星球体                                                                                       

This x-ray image taken in 1999 with NASA's Chandra X-ray Observatory shows what astronomers believe is a supernova remnant interacting with the supermassive black hole at the center of the Milky Way galaxy. Scientists studying the object, called Sagittarius A East, theorized that the shock wave created when it went supernova (bright yellow and orange tones) compressed and plowed gas into the gluttonous black hole (large white dot within shock wave) creating a period of intense feeding followed by a period of "starvation." Astronomers think similar relationships between supernovae and black holes may exist throughout the universe.

viMory:  supernova  超新星      Sagittarius   人马座      gluttonous  暴食的