Speaker: Rafail Skalidis (Caltech)

Hosts: Jake Simon & Amanda Weinstein

Title:  High accuracy magnetometry from dust polarization 

Abstract:  In this talk, I present a novel method for estimating the magnetic field strength in the interstellar medium (ISM) of our Galaxy. The ISM magnetic field strength is notoriously difficult to measure. For this reason, there is a longstanding debate about its dynamical importance in star formation. The magnetic field strength can be directly measured, with the Zeeman effect, only in a limited number of cases, hence indirect methods have been developed. The most widely accessible (indirect) methods are based on dust polarization, which probes directly the plane-of-the-sky magnetic field morphology, but not its strength. These indirect  methods are based on the energy balance of incompressible turbulence, contrary to observations which suggest that the ISM is highly compressible. We developed a novel method that accounts for the compressibility of turbulence in the ISM. This allows us to estimate the magnetic field strength more accurately and reliably than previous methods. We tested the accuracy of our new method with synthetic data produced from a suite of numerical simulations and found that it achieves an accuracy better than a factor of two. The proposed method paves the way towards understanding the role of magnetic fields in star formation.