NIR jets driven by high-mass protostars: morphology and composition in the IRAS18264-1152 region

The processes controlling the formation of massive young stellar objects (YSOs) are not yet fully understood, however it is known that accretion and ejection processes are intrinsically related. In the near-infrared (NIR) regime, the protostar and disc are typically obscured, however we can still obtain crucial information about the outflows. We analyse the morphology and chemical composition of the NIR jet structures of the IRAS 18264-1152 massive star forming region via K-band (1.9-2.5 μm) observations obtained with the integral field unit VLT/SINFONI. This region may contain a stellar cluster, with at least three different outflows. We also identify a number of point sources and at least one of them shows a rising spectrum in NIR. This could indicate it is a low-mass YSO, which has not been detected before. Spectroscopic analysis reveal several H₂ emission lines in the jet features, as well as other atomic species, such as [FeII] and Br-gamma. The velocity map as traced by the H₂ shows that this jet is blueshifted and the excitation map indicates that the H₂ emission is shock driven (i.e. H₂ 2.12 μm/H₂ 2.25 μm flux ratios > ~10). Furthermore, we compute K-magnitudes and extinctions, and infer temperatures and H₂ column densities at key locations of the field of view. In conclusion, our NIR observations may support a cluster origin with several H₂ outflows.