Magnetic fields are ubiquitous and essential in star formation. In particular, their role in regulating formation of stars across diverse environments like HII regions needs to be well understood. In this study, we present magnetic field properties toward the S235 complex using near-infrared (NIR) H-band polarimetric observations, obtained with the Mimir and POLICAN instruments. We selected 375 background stars in the field through combination of Gaia distances and extinctions from NIR colors. The plane-of-sky (POS) magnetic field orientations inferred from starlight polarization angles reveal a curved morphology tracing the spherical shell of the HII region. The large-scale magnetic field traced by Planck is parallel to the Galactic plane. We identified 11 dense clumps using 1.1mm dust emission, with masses between 33 and 525M_{sun}_. The clump-averaged POS magnetic field strengths were estimated to be between 36 and 121{mu}G, with a mean of ~65{mu}G. The mass-to-flux ratios for the clumps are found to be subcritical with turbulent Alfven Mach numbers less than 1, indicating a strongly magnetized region. The clumps show scaling of magnetic field strength versus density with a power-law index of 0.52+/-0.07, similar to ambipolar diffusion models. Our results indicate that the S235 complex is a region where stellar feedback triggers new stars, and the magnetic fields regulate the rate of new star formation.

Cone search capability for table J/ApJ/911/81/table1 (Polarimetric properties of the 623 stars in the S235 complex)

Cone search capability for table J/ApJ/911/81/table3 (Polarimetric and photometric properties of the 375 foreground-corrected embedded and background stars in the S235 complex)