Forward Modeling of Magnetic Field Measurements at the Bases of Stellar Coronae through Extreme-ultraviolet Spectroscopy
Measurements of the stellar coronal magnetic field are of great importance for understanding stellar magnetic activity, yet such measurements have been extremely difficult to obtain. Recent studies proposed a new method of obtaining magnetic field measurements based on the magnetic-field-induced transition (MIT) of the Fe x ion. Here we construct a series of stellar coronal magnetohydrodynamics models and synthesize several Fe x emission lines at extreme-ultraviolet wavelengths, and then
... e the magnetic field strength at the bases of the coronae using the MIT technique. Our results show that the technique can be applied to some stars with magnetic fields more than three times higher than that of the Sun at solar maximum. Furthermore, we investigate the uncertainty of the derived magnetic field strength caused by photon counting errors and find that a signal-noise ratio of ∼50 for the Fe x 175 Å line is required to achieve effective measurements of the stellar coronal magnetic field.