Solar coronal magnetic field measurements using spectral lines available in Hinode/EIS observations: Strong and weak field techniques and temperature diagnostics
arXiv:2302.10596 · doi:10.1093/mnras/stad583
Abstract
Recently, it has been proposed that the magnetic-field-induced transition (MIT) in Fe X can be used to measure coronal magnetic field strengths. Several techniques, the direct line ratio technique and the weak and strong magnetic field techniques, are developed to apply the MIT theory to spectroscopic observations taken by EUV Imaging Spectrometer (EIS) onboard Hinode. However, the suitability of coronal magnetic field measurements based on the weak and strong magnetic field techniques has not been evaluated. Besides, temperature diagnostics is also important for measuring coronal magnetic field based on the MIT theory, but how to determine the accurate formation temperature of the Fe X lines from EIS observations still needs investigation. In this study, we synthesized emissions of several spectral lines from a 3D radiation magnetohydrodynamic model of a solar active region, and then derived magnetic field strengths using different methods. We first compared the magnetic field strengths derived from the weak and strong magnetic field techniques to the values in the model. Our study suggests that both weak and strong magnetic field techniques underestimate the coronal magnetic field strength. Then we developed two methods to calculate the formation temperature of the Fe X lines. One is based on differential emission measure analyses, and the other is deriving temperature from the Fe IX and Fe XI line pairs. However, neither of the two methods can provide temperature determination for accurate coronal magnetic field measurements as those derived from the Fe X 174/175 and 184/345 Å line ratios. More efforts are still needed for accurate coronal magnetic field measurements using EIS observations.
arXiv commentAccepted for publication in MNRAS
References in corpus (45)
- CHIANTI -- an atomic database for emission lines -- Paper XVI: Version 10, further extensions
- Differential Emission Measures from the Regularized Inversion of Hinode and SDO data
- Solar UV and X-Ray Spectral Diagnostics
- Extension of the MURaM radiative MHD code for coronal simulations
- EUV emission lines and diagnostics observed with Hinode/EIS
- Microwave and Hard X-Ray Observations of the 2017 September 10 Solar Limb Flare
- An Open Source, Massively Parallel Code for Non-LTE Synthesis and Inversion of Spectral Lines and Zeeman-induced Stokes Profiles
- Persistent Doppler shift oscillations observed with HINODE/EIS in the solar corona: spectroscopic signatures of Alfvenic waves and recurring upflows
- The Magnetic Field in the Solar Atmosphere
- Global maps of the magnetic field in the solar corona
- STiC -- A multi-atom non-LTE PRD inversion code for full-Stokes solar observations
- Growing transverse oscillations of a multistranded loop observed by SDO/AIA
- Measurement of magnetic field and relativistic electrons along a solar flare current sheet
- Inversion of the radiative transfer equation for polarized light
- Numerical simulations of active region scale flux emergence: From spot formation to decay
- Solar Force-free Magnetic Fields
- MHD Waves in open coronal structures
- The Influence of Spatial Resolution on Nonlinear Force-Free Modeling
- Magnetohydrodynamic Fast Sausage Waves in the Solar Corona
- Mapping the magnetic field in the solar corona through magnetoseismology
- Observational Test of Coronal Magnetic Field Models I. Comparison with Potential Field Model
- A coronal seismological study with streamer waves
- Measuring the magnetic field of a trans-equatorial loop system using coronal seismology
- Record-breaking coronal magnetic field in solar active region 12673
- Hinode/EIS measurements of active region magnetic fields
- On the extrapolation of magneto-hydro-static equilibria on the sun
- Non-damping oscillations at flaring loops
- Multi-component Decomposition of Astronomical Spectra by Compressed Sensing
- Large-scale multiconfiguration Dirac-Hartree-Fock calculations for astrophysics: Cl-like ions from Cr~VIII to Zn~XIV
- The source of the major solar energetic particle events from super active region 11944
- Limitations of force-free magnetic field extrapolations: revisiting basic assumptions
- A first spectroscopic measurement of the magnetic field strength for an active region of the solar corona
- Measurements of Coronal Magnetic Field Strengths in Solar Active Region Loops
- Diagnosing the magnetic field structure of a coronal cavity observed during the 2017 total solar eclipse
- Transverse coronal loop oscillations excited by homologous circular-ribbon flares
- Tracing the Chromospheric and Coronal Magnetic Field with AIA, IRIS, IBIS, and ROSA Data
- Coronal Magnetography of a Simulated Solar Active Region from Microwave Imaging Spectropolarimetry
- Hinode/EIS coronal magnetic field measurements at the onset of a C2 flare
- Diagnostic functions of solar coronal magnetic fields from radio observations
- Measurements of Coronal and Chromospheric Magnetic Fields using Polarization Observations by the Nobeyama Radioheliograph
- Application of a magnetic-field-induced transition in Fe X to solar and stellar coronal magnetic field measurements
- Coronal Magnetic Fields Derived from Simultaneous Microwave and EUV Observations and Comparison with the Potential Field Model
- Measurements of the magnetic field strengths at the bases of stellar coronae using the magnetic-field-induced transition theory
- A novel inversion method to determine the coronal magnetic field including the impact of bound-free absorption
- Forward Modeling of Magnetic-field Measurements at the Bases of Stellar Coronae through Extreme-Ultraviolet Spectroscopy