U of M profs part of black hole discovery
By Jim Bender, Winnipeg Sun

First posted: Wednesday, June 08, 2016 07:03 PM EDT | Updated: Wednesday, June 08, 2016 08:07 PM EDT
Two University of Manitoba professors were part of an international astronomy team that just made a new discovery about black holes.

Astronomers Christopher O’Dea, a science prof, and Stefi Baum, the physics and astronomy dean, were key collaborators on the project, which was headed by their former PhD student Grant Tremblay — now an Einstein Postdoctoral Fellow at Yale University.

The team witnessed a never-before-seen cosmic weather event — a cluster of towering intergalactic gas clouds raining in on the super-massive black hole at the centre of a massive elliptical galaxy one billion light-years from Earth.

The observations, published in the journal Nature, mark the first evidence to support the theory black holes feed on clouds of cold gas.

“There’s not really one eureka moment but when you realize what it is, you slap each other on the back and say, ‘Great job,’” O’Dea said from Iceland, where he is vacationing with his wife Baum.

“Black holes play an integral part in the formation of galaxies or a cluster of galaxies when they release their energy ... (Before the discovery), we didn’t understand how black holes got their fuel and this is a piece of the puzzle in that understanding.”

The observation is the first direct evidence dense clouds can coalesce out of hot, intergalactic gas and plunge into the heart of a galaxy to feed its central super-massive black hole. It also re-shapes astronomers’ views on how super-massive black holes feed through a process known as accretion.

“This so-called cold, chaotic accretion has been a major theoretical prediction in recent years, but this is one of the first unambiguous pieces of observational evidence for a chaotic, cold ‘rain’ feeding a super-massive black hole,” Tremblay said, in a press release.

The researchers made their detection using the Atacama Large Millimeter/submillimeter Array, or ALMA — one of the most powerful telescopes in the world. The team focused on the central galaxy in the Abell 2597 Cluster, one of the brightest galaxies in the universe.

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Composite image of?Abell 2597 Brightest Cluster Galaxy. The background image (blue) is from the Hubble Space Telescope. The foreground (red) is ALMA data showing the distribution of carbon monoxide gas in and around the galaxy. The pull-out box is the ALMA data of the "shadow" (black) produced by absorption of the millimeter-wavelength light emitted by electrons whizzing around powerful magnetic fields generated by the galaxy's supermassive black hole. The shadow indicates that cold clouds of molecular gas are raining in o n the black hole. The team that made the discovery include two Winnipeg-based University of Manitoba professors. Credit: B. Saxton (NRAO/AUI/NSF); G. Tremblay et al.; NASA/ESA Hubble; ALMA (ESO/NAOJ/NRAO)

U of M profs part of black hole discovery | Canada | News | Toronto Sun