研究成果藝廊

Magnetic field vectors shown in red as measured in dust polarization by the SMA. Contours show 0.877 mm dust continuum emission (Girart, Rao, and Marrone 2006, Science, 313, 812)

Magnetic fields play a fundamental role in star formation, and the SMA can be used to infer the distribution of magnetic fields associated with star forming regions by observing polarized dust continuum emission. Such observations have been performed toward NGC 1333 IRAS 4A. The obtained image provided the first conclusive evidence of an hourglass-shaped magnetic field in a star forming region, which has been predicted by theory for a long time. Collapsing molecular cloud cores - the birth places of stars - have to overcome the support provided by their magnetic field to form stars. In the process, the competition between gravity pulling inward and magnetic pressure pushing outward was expected to produce a warped, hourglass pattern in the magnetic field within these collapsed cores.