Black holes reveal themselves in the X-ray spectrum

Black holes are the remnant of stars with more than eight solar masses. Everything we know points to their existence – the theory of relativity, cosmology, etc. And yet, only one supermassive black hole – with a mass of more than 6 billion solar masses – has been “photographed” to date with the help of surrounding radiation in the radio wavelength range. But stellar-mass black holes have not yet been seen.

That’s why scientists are pleased that an international team of astrophysicists has now found distinct signatures of the event horizon of black holes that clearly distinguish them from neutron stars – objects comparable in mass and size with black holes, but that do not have an event horizon. This is by far the strongest evidence to date of the existence of stellar-mass black holes.

The team, made up of Mr. Srimanta Banerjee and Professor Sudip Bhattacharyya of the Tata Institute for Fundamental Research, India, and Professor Marat Gilfanov and Professor Rashid Sunyaev of the Max Planck Institute for Astrophysics, Germany, and the Space Research Institute of the Russian Academy of Science, Russia, published this research in a paper in the Monthly Notices of the Royal Astronomical Society.

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