# The Herschel Exploitation of Local Galaxy Andromeda (HELGA) VII: A SKIRT radiative transfer model and insights on dust heating

**Authors:** S. Viaene, M. Baes, A. Tamm, E. Tempel, G. Bendo, J. A. D. L. Blommaert, M. Boquien, A. Boselli, P. Camps, A. Cooray, I. De Looze, P. De Vis, J. A. Fernandez-Ontiveros, J. Fritz, M. Galametz, G. Gentile, S. Madden, M. W. L. Smith, L. Spinoglio, S. Verstocken  
**arXiv:** [1609.08643](https://arxiv.org/abs/1609.08643)  
**Date:** 2016-09-27  
**Summary page:** https://www.summarizepaper.com/en/paper/1609.08643v1/

## Key points

- Researchers investigate interaction between stars and dust grains in galaxies, focusing on Andromeda galaxy (M31)
- Utilization of radiative transfer models to understand dust heating mechanisms on local and global galactic scales
- Challenges posed by high inclination angle of M31 for 3D modeling, requiring accounting for projection effects in simulations
- Panchromatic radiative transfer simulations using SKIRT code accurately reproduce observed morphology and flux density from ultraviolet to sub-millimeter wavelengths
- Model reveals realistic attenuation curve aligning with previous observational estimates
- 91% of absorbed luminosity in M31 attributed to evolved stellar populations, mainly from bright bulge region extending non-locally up to main star-forming ring at 10 kiloparsecs
- Relative contribution of unevolved stellar populations to dust heating varies significantly with wavelength and galactocentric distance
- Correlation observed between dust heating fraction of unevolved stellar populations and NUV-r color as well as specific star formation rate, serving as valuable indicators for identifying dust heating sources at a local scale
- Study provides insights into how stars interact with dust in galaxies, shedding light on complex processes driving galaxy evolution
- Detailed analysis on M31 serves as a stepping stone towards understanding similar phenomena in other galactic systems

## Summary

In the study titled "The Herschel Exploitation of Local Galaxy Andromeda (HELGA) VII: A SKIRT radiative transfer model and insights on dust heating," researchers investigate the interaction between stars and dust grains in galaxies, focusing on the Andromeda galaxy (M31). By utilizing radiative transfer models, they aim to understand the mechanisms behind dust heating on both local and global galactic scales. The high inclination angle of M31 poses challenges for 3D modeling, leading to projection effects that need to be accounted for in simulations. Through a series of panchromatic radiative transfer simulations using the SKIRT code, the researchers are able to reproduce observed morphology and flux density from ultraviolet to sub-millimeter wavelengths fairly accurately. Their model reveals a realistic attenuation curve that aligns with previous observational estimates. Interestingly, they find that 91% of the absorbed luminosity in M31 is attributed to evolved stellar populations, particularly emanating from the bright bulge region. This strong radiation field extends non-locally up to the main star-forming ring at 10 kiloparsecs. Furthermore, the relative contribution of unevolved stellar populations to dust heating varies significantly with wavelength and galactocentric distance. The researchers observe a correlation between the dust heating fraction of unevolved stellar populations and NUV-r color as well as specific star formation rate, suggesting these parameters can serve as valuable indicators for identifying dust heating sources at a local scale. Overall, this study provides valuable insights into how stars interact with dust in galaxies, shedding light on the complex processes that drive galaxy evolution. The detailed analysis conducted on M31 serves as a stepping stone towards understanding similar phenomena in other galactic systems.