HAO Colloquium - On inverting coronal vector magnetic fields from infrared polarimetric observations

Speaker: Alin Razvan Parsachiv, HAO

We present an algorithm capable of inferring coronal vector magnetic field information by inverting observations of polarized light. The Coronal Line emission DataBase inversion (CLEDB) implements two branches that can process Stokes spectro-polarimetric observations of one or two coronal emission lines. The 1-line branch uses analytical approximations to derive line of sight integrated magnetic field products. When posing an inversion problem, the second branch allows for additional constraints. Theoretical calculations stored inside a database can be used to gain intrinsic access to otherwise non-observable input parameters, e.g. atomic alignment, scattering geometry, etc. that can be used to break inherent degeneracies encountered when attempting analytical inversions like in the 1-line case. Thus, by utilizing 2-line Stokes observations, we show how the 3D magnetic fields and volumetric locations of emitting structures for single-point voxels can be recovered. We additionally explore separating the problem of inverting coronal vector magnetic fields into two parts: i. Disentangling the magnetic field orientation by using the newly developed CLEDB framework; ii. Estimate the magnetic field strength without resorting to Stokes V measurements; e.g. from magnetically-induced Doppler plasma oscillations. The goal of robustly resolving vector coronal magnetometry has been hard to achieve. The need for inverting magnetic fields from solar spectro-polarimetric observations is crucial, as the next generation of coronal capable instruments like DKIST Cryo-NIRSP, DL-NIRSP, and UCOMP will become operational.

Date and time: 
Wednesday, May 11, 2022 - 2:00pm to 3:00pm