Forward Modeling of Magnetic-field Measurements at the Bases of Stellar Coronae through Extreme-Ultraviolet Spectroscopy

Abstract

Measurements of the stellar coronal magnetic field are of great importance in understanding the stellar magnetic activity, yet the measurements have been extremely difficult. Recent studies proposed a new method of magnetic field measurements based on the magnetic-field-induced-transition (MIT) of the Fe~{\sc{x}} ion. Here we construct a series of stellar coronal magnetohydrodynamics (MHD) models and synthesize several Fe~{\sc{x}} emission lines at extreme-ultraviolet wavelengths, and then diagnose 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 error and find that a signal-noise ratio of $\sim$50 for the Fe~{\sc{x}} 175 Å~line is required to achieve effective measurements of the stellar coronal magnetic field.

12 pages, 7 figures

References in corpus (14)

• CHIANTI -- an atomic database for emission lines -- Paper XVI: Version 10, further extensions
• Large-scale magnetic topologies of early M dwarfs
• Global maps of the magnetic field in the solar corona
• Probable detection of an eruptive filament from a superflare on a solar-type star
• Indications of stellar coronal mass ejections through coronal dimmings
• Magnetospheric Structure and Atmospheric Joule Heating of Habitable Planets Orbiting M-dwarf Stars
• A stellar flare-coronal mass ejection event revealed by X-ray plasma motions
• The global and small-scale magnetic fields of fully convective, rapidly spinning M dwarf pair GJ65A and B
• The Influence of Coronal Mass Ejections on the Mass-loss Rates of Hot-Jupiters
• Magnetic Field of the Eclipsing M Dwarf Binary YY Gem
• The source of the major solar energetic particle events from super active region 11944
• Large-scale multiconfiguration Dirac-Hartree-Fock calculations for astrophysics: Cl-like ions from Cr~VIII to Zn~XIV
• A first spectroscopic measurement of the magnetic field strength for an active region of the solar corona
• Measurements of the magnetic field strengths at the bases of stellar coronae using the magnetic-field-induced transition theory

Cited by in corpus (1)

• Solar coronal magnetic field measurements using spectral lines available in Hinode/EIS observations: Strong and weak field techniques and temperature diagnostics