What is at the heart of an active galaxy? Researchers believe that massive black holes millions of times more massive than our sun comprise galactic cores, according to NASA. This video demonstrates this theory and lets you travel into the center of an active galaxy--known as an Active Galactic Nuclei (AGN).
The spaces surrounding these supermassive black holes may be far from dormant, however, flickering in many colors and earning the entire object class the title of Active Galactic Nuclei (AGN). Pictured above is a video illustrating how an active galactic nucleus may appear up close. AGN typically sport massive accretion disks feeding the central black hole, as well as powerful jets shooting electrically charged matter far into the surrounding universe. Clouds of gas and dust seen orbiting the central black holes have recently been found to be so dense that they intermittently eclipse even penetrating x-rays from reaching us. These X-ray dimming events, as short as hours but as long as years, were detected in an analysis encompassing over a decade of data taken by the NASA's orbiting Rossi X-ray Timing Explorer (RXTE).
Image credit: thebadastronomer/Flickr