JCMT/SCUBA Submillimeter Wavelength Imaging of the Integral-shaped Filament in Orion

Abstract

We present the first high dynamic range and sensitivity images of the submillimeter wavelength continuum emission at 450 and 850 μm of the "integral-shaped filament" in the northern portion of the Orion A cloud, which contains the nearest site of ongoing high-mass star formation. The images trace the morphology and spectral index of optically thin emission from interstellar dust, and they constrain the grain temperature and emissivity. The images reveal a remarkable chain of compact sources embedded in a narrow (<1' = 0.14 pc), high column density filament that extends over the 50' (7 pc) length of the map, with faint extended structure surrounding it. While many compact sources contain extremely young protostars, others may be pre-collapse phase cloud cores. The brightest region, associated with OMC-1, contains a remarkable group of dust filaments that radiate radially away from this high-luminosity core and that coincide with the filaments of NH3 emission. The spectral index is uniform between 450 and 850 μm, except for the ridge sources, the photoheated H II region edges including the Orion bar, and the location of molecular hydrogen shocks.