In a recent study published in Astronomy and Astrophysical Letters, a team of researchers at the Massachusetts Institute of Technology (MIT) used various computer models to examine 69 confirmed binary black holes to help determine their origin and found that the results of their data changed depending on the model of the model. configurations
Essentially, the input consistently altered the output, and researchers want to better understand how and why this occurs and what steps can be taken to have more consistent results.
“When you change the model and make it more flexible or make different assumptions, you get a different answer about how black holes formed in the universe,” Sylvia Biscoveanu, an MIT graduate student working at the LIGO Laboratory and co-author of the study, he said in a statement.
“We show that people need to be careful because we’re not yet at the stage with our data where we can believe what the model is telling us.”
Like binary stars, binary black holes are two massive objects orbiting each other, with both having the ability to collide or merge, with another shared characteristic being that black holes are sometimes born from the collapse of ‘dying massive stars, also known as binary stars. a supernova
But how binary black holes originated remains a mystery, as there are two current hypotheses about their formation: “binary field evolution” and “dynamical assembly.”
Field binary evolution involves the explosion of a pair of binary stars, giving rise to two black holes in their place, which continue to orbit each other as before.
Since they initially orbited each other as binary stars, it is thought that their spins and inclinations should also be aligned.
Scientists also hypothesize that their aligned spins indicate that they originated from a galactic disk, given their relatively peaceful environment.
Dynamical assembly involves when two individual black holes, each with their own unique inclination and spin, eventually come together through extreme astrophysical processes to form their own binary black hole system.
It is currently hypothesized that this pairing would likely occur in a dense environment such as a globular cluster, where thousands of nearby stars could force two black holes together.
The real question is: what fraction of binary black holes originates from each respective method? Astronomers believe that answer lies in the data, specifically measurements of the black hole’s spin.
Using the 69 confirmed binary black holes, astronomers have determined that these massive objects could originate in both globular clusters and galactic disks.
The LIGO Laboratory in the United States has worked with its Italian counterpart, Virgo, to determine the spins (rotation periods) of the 69 confirmed binary black holes.
“But we wanted to know, do we have enough data to make that distinction?” said Biscoveanu. “And it turns out things are messy and uncertain, and it’s harder than it looks.”
For the study, the researchers continuously adjusted a series of computer models to see if their results agreed with each model’s predictions.
One such model was set up to assume that only a fraction of binary black holes with aligned spins were produced, where the rest have random spins. Another model was fitted to predict moderately contrasted spin orientation.
In the end, their findings indicated that the results changed consistently according to the fitted models.
Essentially, the results were constantly altered based on tweaks to the model, meaning that more data than the 69 confirmed binary black holes is likely needed to have more consistent results.
“Our paper shows that your result depends entirely on how you model your astrophysics, rather than the data itself,” Biscoveanu said.
“We need more data than we thought, if we want to make a statement that is independent of the astrophysical assumptions we make,” said Salvatore Vitale, who is an associate professor of physics at the Kavli Institute for Astrophysics and Space Research. at MIT and lead author of the study.
But how much more data will astronomers need? Vitale estimates that the LIGO network will be able to detect a new binary black hole every few days once the network returns to service in early 2023.
“The measurements of the spins that we have now are very uncertain,” Vitale said.
“But as we accumulate a lot of them, we can get better information. Then we can say that no matter how detailed my model is, the data always tells me the same story, a story that we can then believe.”
This article was originally published by Universe Today. Read the original article.