Indian scientists develop novel method to measure distances in deep space using pulsars
A team of Indian astronomers, including researchers from IIT Kanpur, has developed a new technique to measure distances in space using pulsars, the dense and rapidly spinning remnant cores of dead stars. Pulsars emit beams of radio waves that sweep across the Earth, similar to a lighthouse, with an extraordinarily fixed spinning rate, making them act as cosmic clocks.
The researchers combined two effects experienced by pulsar signals as they travel through the interstellar medium: dispersion measure (DM) and scatter broadening. DM increases steadily as radio waves pass through more material, while scattering depends on how clumped or turbulent that material is along the path. By jointly analyzing these two observables, scientists can estimate the distance traveled by the wave through the interstellar medium.
This approach significantly reduces reliance on existing Galactic free-electron density models, which are often poorly constrained in many regions of the Milky Way. The technique has been demonstrated using pulsars located toward the Gum Nebula, a large and complex structure in the southern part of our Galaxy.
The new method has the potential to improve Galactic electron density models and yield more reliable estimates of key pulsar properties, such as their true velocities, spatial distribution, and intrinsic radio luminosities. It may also be applicable to powerful extragalactic radio flashes like Fast Radio Bursts (FRBs).
