Description
The Galactic magnetic field plays a crucial role in many astrophysical processes in our Milky Way such as star formation and cosmic-ray propagation. It fulfills multiple roles: for example, it maintains the energy balance in the Milky Way and transports angular momentum. Understanding the Galactic magnetic field is important, as it affects many observations from outside of our Milky Way, such as Ultra-High-Energy Cosmic-Rays (UHECRs).
Over the past few years, various models have been assembled describing the Galactic magnetic field. Although they are all based on observational data, they each predict a different field structure.
With this research, we will determine which of the currently available Galactic magnetic field models best describes observed data from the Interstellar Polarization Survey (IPS) (Magalhães et al. 2005, Versteeg et al. 2023). The IPS is an optical (V-band) survey of 38 fields (0.3° by 0.3°) mainly located near the Galactic plane. Starlight is partially linearly polarized by the absorption of non-spherical dust grains which align themselves with the magnetic field. Therefore, the polarization of starlight tells us about the orientation of the plane-of-sky component of the magnetic field. We use Galactic magnetic field models and combine them with dust models to simulate polarization angles. We compare these modeled polarization angles with the observed ones to identify which model fits the observed data best.
So far, we compared starlight polarization data from two mid-latitude IPS fields, one above and one below the Galactic plane, to modeled polarization angles. For both fields, the Janson and Farrar (2012) model fits the data best, with the averaged observations following the predicted polarization angle as a function of distance. We also show that our model fits depend significantly on the particular dust model used.
| Talk category | NOVA Network 2 |
|---|---|
| Preference for a talk or poster | Poster |
