Description
The inner 100 pc of the Central Molecular Zone (CMZ) of the Milky Way is characterized by extreme conditions—high gas densities, vigorous turbulence, and strong magnetic fields—that differ markedly from those in the Galactic disc. Yet, despite this abundance of dense gas, the star formation rate is observed to be roughly a factor of two lower than that in the disc, which is a long-standing puzzle. In our study, we use the 850 μm polarized dust emission data from the JCMT BISTRO (B-fields In STar-forming Region Observations) survey, with a spatial resolution of 14.6″, to probe the magnetic fields in a number of molecular clouds located in the western CMZ (spanning a 0.3° × 0.2° area centered around (l, b) = (359.608°, –0.037°) between the 20 km s⁻¹ cloud and Sgr C).
Our analysis reveals that these clouds exhibit strong magnetic fields on the order of ~1 mG and are both magnetically subcritical and sub-Alfvénic. These characteristics indicate that magnetic fields provide significant support against gravitational collapse and turbulent compression. We, therefore, propose that the magnetic fields could play a dynamical role in stabilizing the molecular clouds, effectively suppressing star formation in these extreme environments. This magnetic field regulation may help to explain the observed low star formation
