本研究的對象為南天最明亮的HII 區域之一，RCW57，其中所包含的許多大質量恆星及紅外超量天體指示此區域為極年輕的恆星形成區域。本研究使用南非IRSF 紅外巡天設施 (Infra-Red Survey Facility) 中的儀器 SIRPOL，取得RCW57 近紅外線JHKs 三個波段的偏極化影像。在本研究中發現，RCW57 整體區域裡有中央對稱的偏極化結果，指示此區域中的偏極化主要來自於雲氣散射機制。在尺度較小的區 域，如IRS-1 #60，來自於塵埃散射的偏極化也被偵測到，指示其間可能的塵埃及氣體分佈情形。而對於背景恆星透射造成之偏極化分析，我們並未發現此區域中有任何系統性的偏極化。此結果可能指示在此區域中，由於大量的恆星形成所造成的環境擾動，影響了整個恆星形成區域的磁場結構。 RCW57 is one of the brightest H II regions in the infrared harboring a group of massive stars with infrared excess indicative of their youth. We present the near-infrared JHKs polarization images taken by SIRPOL, an infrared polarimeter camera mounted on the IRSF (Infra-Red Survey Facility) telescope in Sutherland, South Africa. An overall scattering pattern is seen centrally symmetric around the luminous stellar group, indicating their dominant role in illuminating the nebulosity. Organized scattering patterns also reveal special dust distribution around embedded infrared sources, e.g., a dust ridge which may be associated with IRS−1 #60. We find no systematic polarization of background stars, which may indicate an entangled magnetic field structure in a turbulent environment of massive star formation.
