black holes tagged posts

Time evolution of the contour surfaces of the lapse α and the shift vector βi for the head-on collision of two puncture black holes of equal mass M=1 at times t=0,5,7,8,10M and t=15M, from top left to bottom right. Phys. Rev. D 97, 084053, 2018; doi:10.1103/PhysRevD.97.084053

Scientists develop simulation code for new generation of supercomputers. What happens when two black holes merge, or when stars collide with a black hole? This has now been simulated using a novel numerical method. The simulation code ‘ExaHyPE’ is designed in such a way that it will be able to calculate gravitational waves on the future generation of ‘exascale’ supercomputers.

The challenge in simulating black holes lies in the necessity of solving the complex Einstein system of equations...

Sagittarius A*, the black hole at the centre of our own galaxy. Credit: NASA/CXC/MIT/F. Baganoff et al.

Gravitational waves may be forged in the heart of the galaxy, says a new study led by PhD student Joseph Fernandez at Liverpool John Moores University. He sets out the work in a presentation on 3rd April at the European Week of Astronomy and Space Science in Liverpool. Gravitational waves (GWs) are small ripples in space-time that spread throughout the universe.

When there is a change in air pressure on Earth, this change moves outwards in the form of sound waves. Analogously, when pairs of compact objects – like black holes (BHs) or neutron stars (NSs) – form binaries and rotate around one another, the gravitational field around them changes, producing GWs that also move outwards.

This ...

An outburst from V404 Cygni. Credit: NASA’s Goddard Space Flight Center

Black holes are famous for their muscle: an intense gravitational pull known to gobble up entire stars and launch streams of matter into space at almost the speed of light. It turns out the reality may not live up to the hype. In a paper published today in the journal Science, University of Florida scientists have discovered these tears in the fabric of the universe have significantly weaker magnetic fields than previously thought.j

A 40-mile-wide black hole 8,000 light years from Earth named V404 Cygni yielded the first precise measurements of the magnetic field that surrounds the deepest wells of gravity in the universe...