University researchers discover black hole in our Galaxy spinning rapidly around itself
A University of Southampton-led project has shown a black hole spinning near its maximum possible rate around its axis.
The study, funded by the Royal Society and published in the Astrophysical Journal, comprised an international team of astronomers led by the University and sheds more light on the characteristics of black holes and the environment surrounding them.
Using observations from state-of-the-art technology, the team of researchers found evidence that a stellar-mass black hole in our Galaxy (known as 4U 1630-472) is rotating rapidly (at a speed of 92-95% of the theoretically-allowed rotational speed) around its axis while sucking in falling material. It is subject to gravitational stresses and temperatures so high that it begins to shine brightly in X-rays, which were seen by astronomers using telescopes.
According to Einstein's General Theory of Relativity (GR), if a black hole is rotating rapidly, then it will modify the space and time around it in a way which is different than that for a black hole which is not rotating.
Such modifications from high spin rates leave an impression on the shape of the radiation from the material rotating very close to the black hole before disappearing. Therefore, if the change in shape of the emitting spectra can be determined somehow, then the GR can be used to measure the black hole spin.
The findings from this study are significant as previously high spin rates of approximately five black holes have been quantified accurately.
The study, funded by the Royal Society and published in the Astrophysical Journal, comprised an international team of astronomers led by the University and sheds more light on the characteristics of black holes and the environment surrounding them.
Using observations from state-of-the-art technology, the team of researchers found evidence that a stellar-mass black hole in our Galaxy (known as 4U 1630-472) is rotating rapidly (at a speed of 92-95% of the theoretically-allowed rotational speed) around its axis while sucking in falling material. It is subject to gravitational stresses and temperatures so high that it begins to shine brightly in X-rays, which were seen by astronomers using telescopes.
According to Einstein's General Theory of Relativity (GR), if a black hole is rotating rapidly, then it will modify the space and time around it in a way which is different than that for a black hole which is not rotating.
Such modifications from high spin rates leave an impression on the shape of the radiation from the material rotating very close to the black hole before disappearing. Therefore, if the change in shape of the emitting spectra can be determined somehow, then the GR can be used to measure the black hole spin.
The findings from this study are significant as previously high spin rates of approximately five black holes have been quantified accurately.
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