nanohertitä

Nanohertz is a unit of frequency in the International System of Units (SI), representing one billionth of a hertz (10⁻⁹ Hz). It is used to describe extremely low-frequency oscillations, typically in the context of gravitational wave astronomy or certain astrophysical phenomena. The term derives from the prefix "nano-," which denotes a factor of 10⁻⁹, combined with "hertz," the SI unit of frequency.

Nanohertz frequencies are particularly relevant in the study of gravitational waves, which are ripples in spacetime predicted by Albert Einstein’s theory of general relativity. These waves are generated by massive cosmic events, such as the merging of supermassive black holes or the rotation of neutron stars. Due to their immense energy and distance from Earth, these signals often fall within the nanohertz range, making them challenging to detect with conventional methods.

Detecting nanohertz gravitational waves typically requires long-term observations using pulsar timing arrays (PTAs). PTAs monitor the precise rotational periods of millisecond pulsars—highly stable, rapidly spinning neutron stars that emit beams of electromagnetic radiation. Variations in these periods, caused by passing gravitational waves, can be measured over years, allowing scientists to infer the presence of low-frequency waves.

Beyond gravitational wave research, nanohertz frequencies appear in other fields, such as geophysics and astrophysics. For example, they may describe ultra-low-frequency oscillations in planetary cores or the rotational frequencies of certain celestial objects. The study of nanohertz phenomena continues to advance our understanding of the universe’s largest-scale structures and fundamental physics.