Unusual new type of black-hole quasar discovered
A research team has discovered a surprising new class of quasars- a super-bright disk of hot gas surrounding a black hole- in distant galaxies that even the most current theories had not predicted.
Washington: A research team has discovered a surprising new class of quasars- a super-bright disk of hot gas surrounding a black hole- in distant galaxies that even the most current theories had not predicted.
"The gas in this new type of quasar is moving in two directions: some is moving toward Earth but most of it is moving at high velocities away from us, possibly toward the quasar`s black hole," study co-author Niel Brandt, Distinguished Professor of Astronomy and Astrophysics at Penn State University said.
The researcher said that they used the Doppler shift for light to tell whether the gas in these quasars is moving away from Earth or toward these distant black holes, which have a mass from millions to billions of times that of the Sun.
Matter around these black holes forms a quasar disc that is bigger than Earth`s orbit around the Sun and hotter than the surface of the Sun. These quasars generate enough light to be seen across the observable universe.
The international research team, led by Patrick Hall of York University in Toronto, Canada, discovered the unusual quasars with data from a large sky survey, the Sloan Digital Sky Survey (SDSS-III).
Hall said that matter falling into black holes may not sound surprising, but what they found is, in fact, quite mysterious and was not predicted by current theories.
Hall asserted that the gas in the disc must eventually fall into the black hole to power the quasar, but what is often seen instead is gas blown away from the black hole by the heat and light of the quasar, heading toward us at velocities up to 20 percent of the speed of light.
Hall said there is one other possible explanation for these objects. It could be that the gas moving away from us is not falling into the black hole but is orbiting around it, just above the disc of hot gas, and is very gradually being pushed away from the black hole.
A wind like that will show gas moving both toward us and away from us.
The study is published in the journal Monthly Notices of the Royal Astronomical Society.