Free Astronomy Magazine May-June 2016

SPACE CHRONICLES Behemoth black hole found in an unlikely place A stronomers have uncovered a near-record-breaking super- massive black hole, weighing 17 billion suns, in an unlikely place: in the center of a galaxy in a sparsely populated area of the universe. The observations, made by NASA's Hub- ble Space Telescope and the Gemini telescope in Hawaii, could indicate that these monster objects may be more common than once thought. Until now, the biggest supermassive black holes — those roughly 10 bil- lion times the mass of our sun — have been found at the cores of very large galaxies in regions of the uni- verse packed with other large gal- axies. In fact, the current record holder tips the scale at 21 billion suns and resides in the crowded Coma galaxy cluster, which consists of over 1,000 galaxies. "The newly discovered supersized black hole re- sides in the center of a massive ellip- tical galaxy, NGC 1600, located in a cosmic backwater, a small grouping of 20 or so galaxies," said lead dis- coverer Chung-Pei Ma, a University of California-Berkeley astronomer and head of the MASSIVE Survey, a study of the most massive galaxies and supermassive black holes in the local universe. While finding a gi- gantic black hole in a massive galaxy in a crowded area of the universe is to be expected — like running across by NASA T his computer-simulated image shows a supermassive black hole at the core of a galaxy. The black region in the center represents the black hole's event horizon, where no light can escape the massive object's gravitational grip. The black hole's powerful gravity distorts space around it like a funhouse mirror. Light from back- ground stars is stretched and smeared as the stars skim by the black hole. [NASA, ESA, and D. Coe, J. Anderson, and R. van der Marel (Space Telescope Science Institute)] clusters like the Coma cluster. So the question now is, ‘Is this the tip of an iceberg?' Maybe there are more monster black holes out there that don't live in a skyscraper in Manhat- tan, but in a tall building some- where in the Midwestern plains." The researchers also were surprised to discover that the black hole is 10 a skyscraper in Manhattan — it seem- ed less likely they could be found in the universe's small towns. "There are quite a few galaxies the size of NGC 1600 that reside in av- erage-size galaxy groups," Ma said. "We estimate that these smaller groups are about 50 times more abundant than spectacular galaxy