Magnetic field structure inferred by near infrared polarization in the carina nebula and RCW57A

Abstract

Carina Nebula (NGC3372) and RCW57A (NGC 3576) are among the brightest Galactic nebulae, with a wealth of massive stars and infrared excess stars, suggestive of recent and ongoing star formation. We present near-infrared JHKs polarization images to diagnose the magnetic field structure in these turbulent cloud complexes. Our observations covered only the central part of the Carina Nebula, around Eta Carina where a cavity has been created, for which only moderate polarization is measured, mainly by the general Galactic magnetic field. In contrast, RCW57A is associated with copious molecular clouds, and we were able to infer the hour-glass shaped magnetic field that governs the cloud morphology.