2012A&A...542L..10O

We investigate the gas dynamics and the physical properties of photodissociation regions (PDRs) in IC 1396A, which is an illuminated bright-rimmed globule with internal structures created by young stellar objects. Our mapping observations of the [CII] emission in IC 1396A with GREAT onboard SOFIA revealed the detailed velocity structure of this region. We combined them with observations of the [CI] ³P₁-³P₀ and CO(4-3) emissions to study the dynamics of the different tracers and physical properties of the PDRs. The [CII] emission generally matches the IRAC 8µm, which traces the polycyclic aromatic hydrocarbon (PAH) emissions. The CO(4-3) emission peaks inside the globule, and the [CI] emission is strong in outer regions, following the 8µm emission to some degree, but its peak is different from that of [CII]. The [CII] emitting gas shows a clear velocity gradient within the globule, which is not significant in the [CI] and CO(4-3) emission. Some clumps that are prominent in [CII] emission appear to be blown away from the rim of the globule. The observed ratios of [CII]/[CI] and [CII]/CO(4-3) are compared to the KOSMA-τ PDR model, which indicates a density of 10⁴-10⁵cm^–3.