Röntgenbinärer

Röntgenbinärer, also known as X-ray binaries, are astronomical objects composed of a compact object, typically a neutron star or a black hole, and a normal star. The compact object accretes matter from its companion star through Roche lobe overflow or stellar winds. As this material spirals towards the compact object, it forms an accretion disk and is heated to extremely high temperatures, causing it to emit intense X-ray radiation. This X-ray emission is the defining characteristic of these systems, hence their name.

The observed properties of X-ray binaries depend on the nature of the compact object. Systems with neutron stars are often referred to as X-ray pulsars if the neutron star is rotating and has a magnetic field that channels accreting matter to its magnetic poles, producing pulsed X-ray emission. Black hole X-ray binaries, on the other hand, do not exhibit pulsations from the compact object itself. Instead, their X-ray emission is more variable and can be observed in different spectral states, reflecting changes in the accretion flow and the black hole's environment.

X-ray binaries are crucial for understanding fundamental physics, including the behavior of matter under extreme gravity, the properties of neutron stars, and the formation and evolution of black holes. Studying their X-ray spectra, light curves, and orbital parameters allows astronomers to determine the masses and radii of the compact objects and their companions, probe the physics of accretion disks, and investigate relativistic effects. They are also important laboratories for testing theories of stellar evolution and binary star interactions.