Modelling the cold dust in nearby spiral galaxies with radiative
  transfer
  Cosmic dust grains are one of the fundamental ingredients of the interstellar
medium (ISM). In spite of their small contribution to the total mass budget,
dust grains play a significant role in the physical and chemical evolution of
galaxies. Over the past decades, a plethora of multi-wavelength data, from UV
to far-infrared, has increased substantially our knowledge on the dust
properties of nearby galaxies. Nevertheless, one regime of the spectrum, the mm
range, remains relatively unexplored. Thanks to the new, high-resolution data
in the mm range observed with the NIKA2 instrument and our radiative transfer
framework, we aim to firmly characterise the physical properties of the very
cold dust (<15K), and to quantify the importance of different emission
mechanisms in the mm. So far, we have developed a methodology to use dust
radiative transfer modelling and applied it to a small group of face-on spiral
galaxies. The combination of the new NIKA2 data with our radiative transfer
techniques would provide the right conditions to generate an accurate model of
the interplay between starlight and dust in a sizeable sample of
spatially-resolved nearby galaxies.
