American and European astrophysicists with Spanish participation have predicted the presence of binary 30-solar mass black holes similar to the Milky Way galaxies, contrary to previous theories. Their calculations are made possible thanks to an open-source program that creates accurate simulations of individual stars as well as those in binary pairs; additionally, they predict their growth over time.
This morning’s study published in Nature Astronomy used POSYDON for the first time ever as a tool to examine merging binary black holes. Furthermore, new information has also been gained regarding galaxies similar to our own Milky Way, which contain black hole formation through mergers that eventually form black holes that resemble those seen within.
As part of their new developments made to the POSYDON program to simulate the population of binary stars, an international team of researchers led by the University of Geneva (UNIGE), in conjunction with the Institute of Space Sciences CSIC, the Institute of Space Studies Catalonia, the IEEC, and Northwestern University Florida, have predicted that galaxies such as our Milky Way may contain binary black holes weighing 30 solar masses each.
Black holes with stellar masses are structures formed from the collapse of stars, with their gravitational fields so powerful that no matter or radiation can escape their detection, making their detection quite an undertaking.
Thus, it is evident that LIGO’s observation of waves caused by the merging of two black holes was an incredible event.
According to the research team, two black holes able to collide at the source of the signal had masses approximately 30 times larger than that of our Sun and were 1.5 billion light years apart.
Though black holes remain an intractable problem for science, researchers have made progress modeling binary stars using software. By doing so, they’ve found better answers by combining theory with observational data.
“Since it is impossible to directly observe the formation of binary black holes that merge, simulations are necessary in order to recreate their observations. Our method includes modeling binary star systems from their creation through their development into binary black hole systems,” according to Simone Bavera of the UNIGE Astronomy Department.
“This is only the start. With POSYDON software’s capability of studying the development and growth of merging black holes in binary systems, we see promise for understanding gravitational waves.” These remarks were made by scientists from ICE-CSIC as well as Konstantinos Kovlakas from IEEC.
“He described his framework as providing insight into the physics of huge stars, whether alone or as binary systems, and their varied manifestations, such as X-ray binaries, type Ia supernovae, gamma-ray explosions, and many other phenomena”.
Understanding the causes of binary black hole mergers seen in 2015 involves comparing theoretical predictions with actual data, using an approach that mimics the growth of hundreds of millions of star-bilateral systems to analyze statistical effects associated with merging events and their sources, gravitational waves.
Over time, scientists have employed models incorporating algorithms that simulate the development of stars and their binary interactions as a means of accomplishing this feat.
POSYDON, an open-source software created as an open-source project, makes use of a vast catalog of already calculated simulations of single and binary stars in order to predict future binary systems using machine learning algorithms in less than one second, according to researchers.
Pre-POSYDON models predicted a low rate for merging black holes within galaxies similar to our Milky Way galaxy and did not account for masses 30–40 times that of our Sun forming into single black holes that merge together.
Posydon has provided evidence that large black holes can exist in galaxies similar to the Milky Way and has made improved predictions based on merging binary properties of black holes such as their mass and spin.
This study, the first ever using POSYDON software to examine binary black hole mergers, offers new insights into their mechanism and gives researchers new understanding. They are in the process of creating the next version of POSYDON that will include comprehensive binar and stellar simulations and will support various galaxy types more fully than ever before.
