ASIAA SMA - Sub-Millimeter Array, ASIAA SMA
Home \ Science \ Scientific Highlights

Scientific Highlights with the SMA

Interpreting the Role of the Magnetic Field from Dust Polarization Maps

Interpreting magnetic field morphologies in molecular clouds from dust polarization observations: a schematic illustration of the angle |δ| across an evolutionary sequence in 3 phases from (I) over (IIA) / (IIB) to (III). Red segments indicate magnetic field orientations. Black contours display dust emission. The angle |δ| is measured between the magnetic field and the dust emission gradient orientations (not shown). The black dotted squares in (I) mark the precursor regions for (IIA) and (IIB). Blue dashed areas indicate regions with close alignment between field and intensity gradient orientations. Yellow areas mark zones with large deviations. Green areas are in between. Mean field orientations (red dotted lines) and dust emission major axis (black dotted lines) are shown in (IIA) and (IIB). Accretion and outflow orientations are shown with black dotted lines in (III). The magnetic field significance ΣB measures the ratio between the magnetic field tension force and gravity. Arrows with |δ|++(ΣB++) and |δ|+ (ΣB +) indicate directions of significant and moderate increase in |δ| (ΣB). Thus, the angle |δ| provides a simple measure to estimate and access the role of the magnetic field from large-scale complexes (I) to collapsing cores (III) (Koch, Tang & Ho, 2013, ApJ, 775, 77 ADS).


Open the larger image


Valid XHTML 1.0 Transitional Valid CSS!