# Towards understanding the Planck thermal dust models

## TL;DR

This paper compares three Planck thermal dust emission models to identify key differences in their parameters, which is crucial for improving cosmic microwave background measurements, especially for detecting primordial B-modes.

## Contribution

It provides a detailed comparison of three Planck dust models, highlighting differences caused by priors and background contributions, aiding future CMB analysis.

## Key findings

- Significant differences in spectral index, optical depth, and dust temperature among models.
- Differences stem from priors and cosmic infrared background contributions.
- Insights help refine dust modeling for CMB experiments.

## Abstract

Understanding the properties of dust emission in the microwave domain is an important premise for the next generation of cosmic microwave background (CMB) experiments, devoted to the measurement of the primordial $B$-modes of polarization. In this paper, we compare three solutions to thermal dust emission by the Planck Collaboration \cite{PlanckDust03,planck_16,planck_com} to point out significant differences between their respective parameters (the spectral index $\beta$, the optical depth $\tau$ and the dust temperature $T_d$). These differences originate from e.g. the priors on the parameters or the contribution of the Cosmic infrared background (CIB).