HAO Colloquium Series presents Juan Manuel Borrero, Kiepenheuer Institute for Solar Physics (Freiburg, Germany)

Comparison of inversion codes for polarized line formation in MHD simulations. Milne-Eddington codes

Milne-Eddington (M-E) inversion codes for the radiative transfer equation are the most widely used tools to infer the magnetic field from observations of the polarization signals in photospheric and chromospheric spectral lines. Unfortunately, a comprehensive com- parison between the different M-E codes available to the solar physics community is still missing, and so is a physical interpretation of their inferences. In this contribution we offer a comparison between three of those codes (VFISV, ASP/HAO, and HELIX). These codes are used to invert synthetic Stokes profiles that were previously obtained from realistic non-grey 3D MHD numerical simulations. The results of the inversion are compared with each other and with those from the MHD simulations. In the first case, the M-E codes retrieve values for the magnetic field strength, inclination and line-of-sight velocity that agree with each other within σB ≤ 35 (Gauss), σγ ≤ 1.2◦, and σv ≤ 10 m s−1, respectively. Additionally, M-E inversion codes agree with the numerical simulation

Date and time: 
Tuesday, July 22, 2014 - 3:00pm to 4:00pm
2139 - Captain Mary