68 km/sec.

“Font-Ribera and his team…pioneered a method of measuring BAOs by using quasars, which are galaxies that are far brighter than normal due to the activity of a supermassive black hole at their center. As matter falls into the black hole, it grows extremely hot, radiating light at far brighter wavelengths and over farther distances than conventional galaxies. This allowed the scientists to measure the mass distribution of the universe out to 12 billion years.”

By incorporating quasars into the field of study, physicists determine the expansion rate of the universe to within 2.2 accuracy. That rate: 68 kilometers per second (which, for the Douglas Adams aficionados out there, translates into 42 miles per second.) “The uncertainty is plus or minus only a kilometer and a half per second.”

A Light in the Deepest Dark.

“‘We think there are only about 100 bright quasars with redshift higher than 7 over the whole sky,’ concludes Daniel Mortlock, the leading author of the paper. ‘Finding this object required a painstaking search, but it was worth the effort to be able to unravel some of the mysteries of the early Universe.’“

European astronomers find the farthest quasar yet discovered, 12.9 billion light years away and dating to only 770 million years after the Big Bang. “This brilliant beacon, powered by a black hole with a mass two billion times that of the Sun, is by far the brightest object yet discovered in the early Universe.“

Not Exactly Soundgarden.

“The more black holes eat, the more they spill, and it is widely thought that their feeding frenzies power the violence seen in the nuclei of many galaxies, including the powerful quasars that are so bright they outshine their parent galaxies.” The NY Times delves into the strange sounds emanating from black holes. “The frequency of these waves was equivalent to a B flat, 57 octaves below middle C, the astronomers calculated.“