Source: NASA / CXC / University of Cambridge / C. Reynolds et al.
The “Theory of everything” is a big idea that all forces, particles and interactions in Universe connect with each other under the same framework of physics with a simplistic and elegant theory. Such theory is the String Theory or when unifying different flavors of the String theory together is the M-Theory (M stands for “Magic” or “Mystery”). Even though there are many variations in the theoretical models and different aspects have been proposed for the String Theory, few of them have been experimentally tested. Not till now!
A scientific team used X-ray data from NASA’s Chandra X-ray Observatory to test the existence of a particle predicted by different concepts of the String Theory. The researchers were looking for a type of particle known as an “axion” and other similar particles. Galaxy clusters, the biggest frameworks in deep space held with each other by gravity, with their strong magnetic fields and X-ray emission can be excellent places to search for evidence for axions. “While it may sound like a long shot to look for tiny particles like axions in gigantic structures like galaxy clusters, they are actually great places to look,” said co-author David Marsh of Stockholm University in Sweden. “Galaxy clusters contain magnetic fields over giant distances, and they also often contain bright X-ray sources. Together these properties enhance the chances that conversion of axion-like particles would be detectable.”
In particular, the team looked at the Perseus galaxy cluster for over 5 days with Chandra, but did not find signals of any axion-like particles, however they were able to constraint the String Theory and rule out several models. “Our research doesn’t rule out the existence of these particles, but it definitely doesn’t help their case,” said co-author Helen Russell of the University of Nottingham in the UK. “These constraints dig into the range of properties suggested by string theory, and may help string theorists weed their theories.”
“Until recently I had no idea just how much X-ray astronomers bring to the table when it comes to string theory, but we could play a major role,” said Christopher Reynolds of the University of Cambridge in the United Kingdom, who led the study. “If these particles are eventually detected it would change physics forever.”
More information can be found here:
https://chandra.si.edu/photo/2020/perseus/Paper Reference: “Astrophysical Limits on Very Light Axion-like Particles from Chandra Grating Spectroscopy of NGC 1275″ by Christopher S. Reynolds, M. C. David Marsh, Helen R. Russell, Andrew C. Fabian, Robyn Smith, Francesco Tombesi and Sylvain Veilleux, 12 February 2020, The Astrophysical Journal.