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Black Hole Cluster Spawns Massive Cloud
Shifty Jim writes in with an article at space.com reporting that a cluster of galaxies harboring black holes may be the source of a massive cloud millions of light years across. Quoting: "A giant cloud of superheated gas 6 million light years wide might be formed by the collective sigh of several supermassive black holes, scientists say. The plasma cloud... might be the source of mysterious cosmic rays that permeate our universe... The plasma cloud is located about 300 million light years away near the Coma Cluster and is spread across a vast region of space thought to contain several galaxies with supermassive black holes... embedded at their centers."
Google "Hawking Radiation". (Thermal radiation thought to be emitted by black holes due to quantum effects - named after British physicist Stephen Hawking, who provided the theoretical argument for its existence in 1974.)
Black holes actually do radiate - they are actually not black at all. The result is that small black holes will evaporate and disappear after a while. Bigger ones are probably indistinguishable from an ordinary star when viewed from a distance. The difference being their mass which would be disproportionate to their luminosity. Read Hawking's "A Brief History of Time" for illumination.
Excuse me, but please get off my Pennisetum Clandestinum, eh!
Actually, it's the *really* small ones(on the order of the mass of maybe half the moon, or smaller) that evaporate very quickly. The supermassive ones radiate at a very low rate and will last many, many, many billions of years. The temperature of the universe(eg: background radiation) will need to drop before they'll be "hotter" than their surroundings. Currently the big black holes are soaking up more radiation than they're emitting(hence, black)
"so what makes this guy think this particular "cloud" has agreater probability of being the source of the "cosmic rays" that "permeate" our universe?"
They don't:
"he new finding could also help explain the unwanted and confusing "noise" scientists observe in the Cosmic Microwave Background (CMB), Kronberg said. The CMB is a ubiquitous radiation in the universe that is said to be a remnant of the Big Bang."
Now, if you read that carefully, it is said that this could explain the *noise* in the CMB, not the CMB itself. Half a point for reading through the article though.