Secret Magnetic Maelstrom in Tarantula Nebula Contributes to the Survival of 30 Doradus

30 Doradus, also known as the Tarantula Nebula, is a region in the Large Magellanic Cloud. Streamlines show the magnetic field morphology from SOFIA HAWC+ polarization maps. These are superimposed on a composite image captured by the European Southern Observatory’s Very Large Telescope and the Visible and Infrared Survey Telescope for Astronomy. Credit: Background: ESO, M.-R. Cioni/VISTA Magellanic Cloud survey. Acknowledgment: Cambridge Astronomical Survey Unit. Streamlines: NASA/SOFIA

New research from the Stratospheric Observatory for Infrared Astronomy (SOFIA) has shown that the magnetic fields in 30 Doradus could be the key to its surprising behavior. Most of the energy in 30 Doradus, also called the Tarantula Nebula, comes from the massive star cluster near its center, R136, which is responsible for multiple, giant, expanding shells of matter. But in this region near the nebula’s core, within about 25 parsecs of R136, things are a bit weird. The gas pressure here is lower than it should be near R136’s intense stellar radiation, and the area’s mass is smaller than expected for the system to remain stable.

Using SOFIA’s High-resolution Airborne Wideband Camera Plus (HAWC+), astronomers studied the interplay between magnetic fields and gravity in 30 Doradus. Magnetic fields, it turns out, are the region’s secret ingredient.

The recent study, published in The Astrophysical Journal, found the magnetic fields in this region are simultaneously complex and organized, with vast variations in geometry related to the large-scale expanding structures at play.

But how do these complex-but-organized fields help 30 Doradus survive? In most of the area, the magnetic fields are incredibly strong. They’re strong enough to resist turbulence, so they can continue to regulate gas motion and hold the cloud’s structure intact. They’re also strong enough to prevent gravity from taking over and collapsing the cloud into stars.

However, the field is weaker in some spots, enabling gas to escape and inflate the giant shells. As the mass in these shells grows, stars can continue to form despite the strong magnetic fields.

Observing the region with other instruments can help astronomers better understand the role of magnetic fields in the evolution of 30 Doradus and other similar nebulae.