Utilizing the Atacama Large Millimetre/submillimetre Array (ALMA), one of the most powerful telescopes in the world, U.S. Naval Research Laboratory (NRL) astrophysicist Dr. Tracy Clarke and an international team of researchers have peered into the feeding habits of a supermassive black hole and witnessed the first evidence of a new diet. The black hole, whose mass is nearly 300 million times that of our sun, is on the verge of gulping down massive clumps of cold gas which each contain as much material as a million suns.
Previously, astronomers generally believed that supermassive black holes at the centers of galaxies slowly grazed on a steadfast diet of hot ionized gas from the galaxy’s halo. The new ALMA observations show that under the right intergalactic conditions, the black hole can instead feed on a chaotic downpour of cold, clumpy clouds that have condensed out of the hot gas and plummeted into the heart of the galaxy where the supermassive black hole resides. These new observations — recently published in a Nature letter led by Dr. Grant Tremblay, Yale Center for Astronomy and Astrophysics — will help recast astronomers models of how supermassive black holes grow through a process known as accretion.
The team of astronomers used ALMA to study an unusually bright cluster of individual galaxies, collectively referred to as Abell 2597, in hopes of mapping the spatial structure and velocity of the cold gas in the system. Earlier work by Clarke revealed that the hot gas in the core of this cluster is riddled with X-ray cavities excavated by powerful radio jets driven by outbursts from the central supermassive black hole. The ALMA observations were aimed at searching for evidence that the powerful radio jets can also pull cold gas out of the cluster core to stop catastrophic runaway cooling.
Grant R. Tremblay, J. B. Raymond Oonk, Françoise Combes, Philippe Salomé, Christopher, P. O’Dea, Stefi A. Baum, G. Mark Voit, Megan Donahue, Brian R. McNamara, Timothy A. Davis, Michael A. McDonald, Alastair C. Edge, Tracy E. Clarke, Roberto Galván-Madrid, Malcolm N. Bremer, Louise O. V. Edwards, Andrew C. Fabian, Stephen Hamer, Yuan Li, Anaëlle Maury, Helen R. Russell, Alice C. Quillen, C. Megan Urry, Jeremy S. Sanders, Michael W. Wise. Cold, clumpy accretion onto an active supermassive black hole. Nature, 2016; 534 (7606): 218http://dx.doi.org/10.1038/nature17969