Free Astronomy Magazine November-December 2016

SPACE CHRONICLES the centers of galaxies. Many of these galactic behemoths are hid- den within a thick doughnut-shape ring of dust and gas known as a torus. Previous observations suggest these cloaking, tire-like structures are formed from the native material found near the center of a galaxy. New data from the Atacama Large Millimeter/submillimeter Array (AL- MA), however, reveal that the black hole at the center of a galaxy named Black hole hidden within its own exhaust by ALMA Observatory S upermassive black holes, mil- lions to billions of times the mass of our Sun, are found at A rtist impression of the heart of galaxy NGC 1068, which harbors an actively feeding supermassive black hole. Arising from the black hole's outer accretion disk, ALMA discovered clouds of cold molecular gas and dust. This material is being accelerated by magnetic fields in the disk, reaching speeds of about 400 to 800 kilometers per second. This mate- rial gets expelled from the disk and goes on to hide the region around the black hole from optical telescopes on Earth. Essentially, the black hole is cloaking itself behind a veil of its own exhaust. [NRAO/AUI/NSF; D. Berry / Skyworks]