Using NASA’s Hubble Space Telescope, astronomers havediscovered a disc very close to a starving black hole – something that shouldnot be there – based on current astronomical theories.
The unexpected thin disc of material was found encircling asupermassive black hole at the heart of the spiral galaxy NGC 3147, located 130million light-years away, according to a study published in the journal MonthlyNotices of the Royal Astronomical Society.
The presence of the black hole disc in such a low-luminosityactive galaxy has astronomers surprised.
Black holes in certain types of galaxies such as NGC 3147are considered to be starving as there is insufficient gravitationally capturedmaterial to feed them regularly.
It is therefore puzzling that there is a thin discencircling a starving black hole that mimics the much larger discs found inextremely active galaxies, the study said.
The disc’s material was measured by Hubble to be whirlingaround the black hole at more than 10 per cent of the speed of light.
At such extreme velocities, the gas appears to brighten asit travels toward Earth on one side, and dims as it speeds away from our planeton the other. This effect is known as relativistic beaming.
Hubble’s observations also show that the gas is embedded sodeep in a gravitational well that light is struggling to escape, and thereforeappears stretched to redder wavelengths. The black hole’s mass is around 250million times that of the Sun.
“This is an intriguing peek at a disc very close to ablack hole, so close that the velocities and the intensity of the gravitationalpull are affecting how we see the photons of light,” explained the study’sfirst author Stefano Bianchi of Roma Tre University in Italy.
Of particular interest, this disc of material circling theblack hole offers researchers a unique opportunity to test Albert Einstein’stheories of relativity.
“We’ve never seen the effects of both general andspecial relativity in visible light with this much clarity,” said MarcoChiaberge of the European Space Agency, and the Space Telescope ScienceInstitute and Johns Hopkins University, both in Baltimore, Maryland.