All posts tagged: accretion disk

MIT astronomers detect oldest known flickering quasar from the cosmic dawn

MIT astronomers detect oldest known flickering quasar from the cosmic dawn

A quasar from the universe’s first 850 million years has started to look less like a distant pinprick and more like a real physical system. By catching it flickering over time, astronomers have traced the structure of matter swirling around one of the earliest known supermassive black holes. What they found deepens one of cosmology’s biggest puzzles. The object, known as J0439+1634, sits at a redshift of 6.51. This means its light comes from a time just 850 million years after the Big Bang. Quasars are among the brightest objects in the universe, powered by supermassive black holes pulling in gas and dust. As that material spirals inward, it heats up and radiates enormous amounts of energy. Sometimes, it outshines the galaxy around it. Many quasars have already been found from this early era, often called the cosmic dawn. What makes this one stand out is not just its age, but its variability. Astronomers at MIT and elsewhere have detected a quasar flickering from the very early universe. This artist’s concept illustrates a quasar accretion …

The physics of no return: What actually happens if you get pulled into a black hole

The physics of no return: What actually happens if you get pulled into a black hole

In 1916, only a year after Albert Einstein had published his general theory of relativity, Karl Schwarzschild used mathematical calculations to show this: If sufficient mass could be placed into an extremely small volume, then this sufficiently dense mass would create a zone where gravity is so strong that nothing, including light, could escape from it. One hundred years later, scientists have actually imaged the shadow of such an object. They have also recorded the gravitational waves produced when two of these celestial bodies collide. However, the ultimate question (the ultimate unresolved question) in science about the fate of matter that crosses an event horizon of a black hole is still unanswered. The answer includes a long list of things: how atomic structure changes or gets stretched during the collapse of the star, spatial distortion due to relativistic time dilation, luminous rings of matter and debris surrounding the black hole, and the nature of the event horizon itself (which has no physical wall). It is simply becoming an irreversible relationship with the universe beyond the …