Tackling the Orion Nebula with SITELLE : a thermodynamic approach

Maxime Royer ( Université Laval )

Ionized nebulae are complex entities comprising temperature fluctuations, turbulence, supersonic colliding flows abundances varying according to the type of emission line used, etc. These processes are still quite ill-understood and HII regions remain major providers of information from which galaxy characteristics, kinematics and evolution are derived. This can lead to bad interpretation of extra-galactic data caused by incomprehension of nebulae micro-physics and may impact the basic galactic knowledge. Following the previous thermodynamic analysis of the HII region Sh2-158, I will be tackling a sub-region of the Orion Nebula with the help of SITELLE and previous developed Monte-Carlo analysis codes. 6 hyperspectral cubes were acquired with nearly thirty lines detected. This data set enables the calculation of numerous diagnostics and physical parameters. Several of those lines are used to create electron density, temperature and pressure maps needed for the thermodynamic analysis. Preliminary density maps [OII], [ClIII] and [SII] and a [NII] temperature map will be shown. These maps will help with the determination of the different ionized volumes of the sub-region. The last step will be the coupling of thermodynamic maps with high spectral resolution multi-ionic velocity map which we have acquired with GHASP at OHP. The coupling of the analysis of the temperature and density fluctuations with velocity fluctuations for different ionization levels will enable a complete thermodynamic diagnostic of this sub-region of the Orion Nebula.