Presentation #231.03 in the session Star Formation.
Massive protostars play a critical role on galaxy evolution and the nearby star formation activity. Despite their importance, the processes of massive star formation remains debatable due to the challenges of accurate measurements of their physical properties of these massive star-forming cores, such as their protostellar mass and envelope mass. The spectral energy distribution (SED) has been a powerful tool to test models against observations. The far-infrared and sub-millimeter part of the SED traces the cold dust in the envelope, while the emission at near- and mid-infrared probes the emission from outflow cavities and/or the inner envelope. However, the SED modeling has known degeneracy. For example, a face-on view of a protostar with a dense envelope could have a similar SED as a protostar with more diffuse envelope viewed edge-on. Such degeneracy hinders precise constraints on model parameters, thus preventing robust tests of massive star formation models. In this study, we utilize the brightness distribution from the mid-infrared images taken by SOFIA/FORCAST to aid the SED modeling developed by the SOFIA Massive Star Formation (SOMA) survey, which tests the turbulent core model. The spatial distribution of mid-infrared emission specifically reflects the inclination angle, which cannot be constrained by the SED modeling. We developed a fitting pipeline to extract the 2D information from mid-infrared images, which is then combined with the previous SED fitting results to characterize the model parameters. Demonstrated in Cepheus A, the parameters become more tightly constrained after our revised modeling pipeline. I will also discuss how this pipeline could apply to a larger sample as well as its limitation.