High-resolution, 3D radiative transfer modeling of nearby DustPedia galaxies

May 18, 2016, 2:45 PM
8h 15m





The DustPedia project aims at conducting a definitive study of interstellar dust in the Local Universe, by gathering multi-wavelength imaging data of nearby galaxies, and modelling them with state-of-the-art modeling tools. As part of the DustPedia project, we create 3D models for a representative set of nearby galaxies using the radiative transfer code SKIRT. We simultaneously derive the 3D distribution and spectral properties of the stellar populations and the interstellar dust in each galaxy, by fitting radiative transfer models directly to imaging data from UV to submm wavelengths. We fully take into account the effects of absorption, multiple scattering and thermal re-emission by the dust in our models.

We present preliminary modelling results on two well-known face-on spiral galaxies, M51 and M81, and focus on the dust heating mechanisms in these galaxies. By using radiative transfer, we take into account the effects of non-local heating, as opposed to for example pixel-by-pixel modelling techniques. We exploit our knowledge of the internal radiation field to investigate the contribution of the evolved and young stellar populations to the heating of the dust at every position in the galaxy. Our results indicate that young stellar populations are not always the dominant heating agent, and that the contribution of evolved population is important as well.

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