That’s a lot of detail about two far-flung objects, especially considering that astrophysicists only directly observed their highly violent end. bottom. To infer more from very little, they combine observations of neutron stars with insights gained from studies of other stars and galaxies, and mathematical models of both observed and hypothetical stars. created a behemoth of The model contains detailed descriptions of the temperature, chemical composition, and other characteristics of 250,000 stars from the interior to the surface, and how these properties change as each star burns its fuel and eventually dies. includes changes. Additionally, the model can simulate an entire galaxy, each containing multiple collections of stars of different ages and chemical compositions.
So, in an effort to uncover the past of merged neutron stars, Stevance and her colleagues worked to reconstruct observed data for neutron stars in models. This allowed us to convey the most likely scenario of what happened before the two stars merged. For example, they concluded that stars share envelopes multiple times because of how long it took for the two bodies to collide. When two binary stars combine envelopes, the gas within their shared envelopes creates a drag force that slows the star’s orbit. This causes the stars to swirl around each other and rapidly reduce the distance between them. Stars had to share their envelopes several times to merge as quickly as the rest of the core.
This study of neutron star mergers builds on decades of astronomical research. Jan Eldridge, a lecturer in astrophysics at the University of Auckland and one of Stevans’s collaborators, believes that Stevans’s colleague had formulated a model of stars 15 years before him to study very distant galaxies. has begun to study the celestial bodies of “When we first created this, it took many years for gravitational waves to be detected,” he says. This 15-year-old model builds on models of stars created by astronomers in the 1970s. This work presents a long and often tortuous scientific process. Generations of astronomers have grappled with tangential questions about stars, inadvertently contributing to new discoveries decades later.
Additionally, Stevance and her team have open-sourced their research, allowing other researchers to unwind the clock on other stars’ activity. Researchers can use this framework to study supernovae, the spectacular explosions of massive stars, said Peter Blanchard of Northwestern University. He was not involved in this research. As astrophysicists study more of these different types of explosions that are predicted to produce many types of heavy elements, they will be able to better explain where all the elements in the universe originated. It is possible that the death of a star forged gold and uranium, eventually merging with other elements to form the Earth, billions of years ago becoming gems and weapons.
To predict the phylogeny of neutron stars, Stevance’s model also needs to infer properties of the galaxies that host them, such as the types of elements they contain and whether they are evenly distributed throughout the galaxy. there was. Hsin-Yu Chen, an astrophysicist at the University of Texas at Austin, who wasn’t involved in the study, said the knowledge could help guide other mergers in the future.
If researchers can find more neutron star mergers, Chen hopes to use them to figure out how fast the universe is expanding to calculate the age of the universe. Chen can use the coalescing gravitational wave signal to calculate the distance from Earth to a neutron star. Then, by analyzing the light emitted by the merger, it estimates how fast the neutron star is moving away, providing an expansion rate. Astrophysicists have so far used different methods to calculate two conflicting rates of the universe’s expansion, so they would like to see more mergers to reconcile this conflict.
The Laser Interferometer Gravitational-Wave Observatory collaboration, which used two detectors in Washington and Louisiana to detect neutron star mergers, is set to return online in May 2023 after a two-year upgrade. . When that happens, the researcher expects he will be able to detect 10 neutron star mergers a year. This should give us many opportunities to delve deeper into the question of the age of the universe. “The next few years are going to be very exciting,” says Blanchard. It was also a very exciting billion years.
