Saturday, April 9, 2011

A quasar's lesson in death, 03.02.11

There is a supermassive black hole at the center of Markarian 231, about 600 million light years away, near the constellation Ursa Major, which is giving scientists some clues into the life cycles of black holes. Irony objectified, it turns out that their massive appetites actually starve them out in the end.

Image credit: Gemini Observatory/AURA, artwork by Lynette Cook.
Mrk 231 is under observation by the Gemini Observatory in Hilo, Hawai’I, and the Gemini Multi-Object Spectrograph (GMOS) on Mauna Kea, Hawai’i. The observatory has estimated that the total flow of matter from Mrk 231 is about 400 times the mass of the Sun, and that it puts out this much every year. Such an enormous appetite, however, cannot go on forever, scientists say.

Black holes are a normal find in the center of galaxies; we even have one of our own in the center of the Milky Way. Mrk 231has allowed scientists to glean data that demonstrates how black holes can be choked out. They are calling their findings a “negative feedback loop,” in which the black hole sucks in matter and energy around it, compresses it into an unimaginably fine stream (probably because of magnetic fields), and then spews it back out. The problem, they say, is that it is spitting its food out too far and too fast. “This is really a last gasp of this galaxy;” says Sylvain Veilleux of the University of Maryland, “The black hole is belching its next meal into oblivion!”

In the final, violent stages of merging with another galaxy, it spits out the material it needs faster and farther away than it can be retrieved. Soon, it will be stripped down to its energetic central quasar.

Quasar is actually a shortened term for “quasi-stellar radio source.” This is a bit of a misnomer, however, as some quasars emit very little of a radio signal, if any, at all. They also are some of the brightest and presumably oldest objects in the universe, and are still being extensively studied.

Credit: NASA.

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