Magnetic fields play a crucial role in many astrophysical phenomena, but measuring them from such a distance is not an easy task. However, researchers have now developed a new approach to take such measurements using methanol, the simplest form of alcohol.
As reported in Nature Astronomy, understanding how methanol behaves in the extreme environments where stars form is not easy, and trying to create an analog in the lab was not successful. The team had to create a theoretical model and then work on it until it was consistent with what is seen in the universe and what can be measured in the lab.
“We developed a model of how methanol behaves in magnetic fields, starting from the principles of quantum mechanics," lead author Boy Lankhaar, from Chalmers University of Technology, said in a statement. "Soon, we found good agreement between the theoretical calculations and the experimental data that was available. That gave us the confidence to extrapolate to conditions we expect in space.”
The calculations necessary to understand methanol’s behavior in detail were extremely tricky. Also, the estimates from this model have to be as accurate as the observations from radio telescopes, otherwise they wouldn’t be very useful.
“Since methanol is a relatively simple molecule, we thought at first that the project would be easy. Instead, it turned out to be very complicated because we had to compute the properties of methanol in great detail,” added co-author Ad van der Avoird, a theoretical chemist from Radboud University.
Methanol is useful because it emits a very specific microwave signal in the dense clouds where stars form. This is known as a maser (microwave amplification by stimulated emission of radiation) and it’s a clear, strong signal. By looking at how magnetic fields affect this signal, researchers hope to find new insights into the formation of massive stars.
“When the biggest and heaviest stars are born, we know that magnetic fields play an important role," Lankhaar added. "But just how magnetic fields affect the process is a subject of debate among researchers. So we need ways of measuring magnetic fields, and that’s a real challenge. Now, thanks to our new calculations, we finally know how to do it with methanol.”
Magnetic fields are found around stars, planets, and black holes of all sizes. Even galaxies have one. Working out how they form and how they behave is a key step in understanding how these celestial bodies work.