In the realm of astrophysics and energy research, scientists are continually seeking new ways to understand the fundamental properties of celestial bodies. Researchers Zhao-Wei Du and Xi-Long Fan, affiliated with the University of Chinese Academy of Sciences, have recently explored how gravitational wave observations can provide insights into the internal physics of neutron stars.
Neutron stars, the remnants of massive stars that have collapsed under their own gravity, are among the densest objects in the universe. Understanding their internal structure can offer valuable insights into the behavior of matter under extreme conditions. In their study, Du and Fan extended the Tolman-Oppenheimer-Volkoff framework, a standard model for describing the structure of neutron stars, to include pressure anisotropy and internal magnetic fields. They considered two types of magnetic field configurations: radial orientation dominated (RO) and transverse orientation dominated (TO), with varying strengths and decay rates.
The researchers found that both pressure anisotropy and magnetic fields can significantly alter the maximum mass that a neutron star can support. These factors also modify the tidal deformability, a measure of how easily a neutron star can be deformed by the gravitational pull of a companion star. Changes in tidal deformability leave measurable imprints on gravitational wave signals emitted during the merger of two neutron stars. For instance, in a binary system consisting of two neutron stars each with a mass of 1.2 times that of the Sun, the presence of anisotropy and a radial orientation dominated magnetic field can make the stars more compact and result in a larger shift in tidal deformability. This shift can be detected at signal-to-noise ratios as low as approximately 18 using the sensitivity expected for the fourth observing run of advanced LIGO and Virgo detectors (O4 power spectral density).
In contrast, transverse orientation dominated magnetic fields produce weaker effects, requiring substantially higher signal-to-noise ratios for detection. The study concludes that gravitational wave observations have the potential to probe the internal structure of neutron stars, offering a new window into the physics of these enigmatic objects. This research was published in the journal Physical Review D.
The findings have implications for the energy sector, particularly in the context of understanding the fundamental forces and behaviors of matter under extreme conditions. While direct applications to energy technologies may not be immediate, the insights gained from such research can contribute to the broader scientific understanding that drives innovation in energy-related fields. For example, understanding the behavior of matter at high densities and the role of magnetic fields can inform the development of advanced materials and technologies for energy storage and generation.
This article is based on research available at arXiv.