February 24, 2014
If the universe seems cold from a distance, birthdays are part of its rebuttal.
The Cloudy Cores of Active Galaxies
Birthday · February 24, 2014
A little universe, just for you
Your date.
Ready to give.
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APOD published February 24, 2014 · Video still. Full image credits are on the original APOD entry below. A publication-date match, not a photo taken on your date. Independent of NASA.
What would it look like to travel to the center of an active galaxy? Most galactic centers are thought to house black holes millions of times more massive than our Sun. 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).