Synopsis

Sailing Choppy Gravitational Seas

Physics 5, s130
Proposed measurements of arrays of pulsars could reveal the secrets of how supermassive black holes form, behave, and evolve.
SKA Organisation/Swinburne Astronomy Productions

Massive astrophysical objects are believed to produce ripples in spacetime called gravitational waves. Proposed or ongoing experiments offer the chance to detect these gravitational waves and use them to study the behavior of the objects that create them. In Physical Review Letters, Chiara Mingarelli of the University of Birmingham, UK, and colleagues analyze the potential and limitations of using data from groups of pulsars for this kind of research.

Pulsars are rotating neutron stars emitting beams of radiation that we see as highly regular radio pulses, much as lighthouses sweep the horizon with warning signals. These pulses will arrive at a detector at intervals that vary because of passing gravitational waves. Like ships sailing across rough seas, the pulses have to travel different distances to the detector, depending on how many peaks and valleys appear along their paths. Collating the arrival times of various ships (or pulsar signals) as they arrive at one port (or detector) forms a picture of the ocean topography.

Mingarelli et al. calculate scenarios for gravitational waves produced by pairs of supermassive black holes orbiting each other. The authors show that much could be learned about black hole masses and spins once future high-sensitivity detectors, combined with knowledge of pulsar distances, allow comparing pulse timing at the earth and at the pulsar. These calculations suggest a plan for how experimental detection of gravitational waves might shed light on the details of black hole formation and evolution. – David Voss


Subject Areas

Astrophysics

Related Articles

Carbon Monoxide Leaves Cosmic Ice with a Kick
Astrophysics

Carbon Monoxide Leaves Cosmic Ice with a Kick

Molecular “kicks” induced by ultraviolet light are predicted to cause carbon monoxide molecules to be released from the icy layers that cover cosmic dust. Read More »

“Spin” Leaves Its Mark on Some Meteorite Craters
Materials Science

“Spin” Leaves Its Mark on Some Meteorite Craters

Numerical simulations reveal that an impact crater’s shape can depend on the impactor’s spin and its degree of cohesion. Read More »

Tension for a Hubble-Tension Solution
Astrophysics

Tension for a Hubble-Tension Solution

An early-Universe spike in dark energy could resolve a disagreement between two cosmic-expansion-rate measurements, but such a spike may conflict with observations of quasar spectra. Read More »

More Articles