Carina nebula 和 RCW 57A 都是銀河系內很明亮的星雲，包含了許多的大質量恆星與紅外超亮的恆星，被認定為是年輕的恆星形成區。我們使用南非 IRSF 紅外巡天設施(Infra-Red Survey Facility)的儀器 SIRPOL，得到了近紅外 JHKs 三個波段的偏極影像。我們發現 Carina nebula 區域中星光的偏極大多為東西向，這很有可能是銀河盤面上的磁場所造成，因為在視野內大質量恆星己經形成並吹出了空腔，可能也破壞了該區域的磁場結構。相對而言 RCW 57A 大質量恆星還埋在雲氣當中，保留了該區域的雲氣和磁場結構。我們發現 RCW 57A 區域中的磁場與雲氣延伸方垂直向且向內彎曲，展現了磁場限制雲氣塌縮的証據。The Carina Nebula (NGC3372) and RCW 57A (NGC3576) 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 taken by SIRPOL, an infrared imaging polarimeter, mounted on the Infra-Red Survey Facility telescope in Sutherland, South Africa, to diagnose the magnetic field structure in these turbulent cloud complexes. Our SIRPOL field covers only the central part of 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, RCW 57A is associated with copious molecular clouds, and we were able to infer the hourglass shaped magnetic field that governs the cloud morphology.
