Global Coronal Magnetic Field Estimation Using Bayesian Inference
arXiv:2401.05022 · doi:10.3847/1538-4357/ad1b57
Abstract
Estimating the magnetic field strength in the solar corona is crucial for understanding different physical processes happening over diverse spatio-temporal scales. However, the high temperatures and low density of the solar corona make this task challenging. The coronal magnetic field is too weak to produce a measurable splitting of the spectral lines using the Zeeman effect, and high temperature causes spectral lines to become weak and broad, making it difficult to detect the small Zeeman splitting. Coronal magneto-seismology, which combines the theoretical and observed properties of magnetohydrodynamic (MHD) waves, can be used to infer the magnetic field strength of oscillating structures in the solar corona, which are otherwise difficult to estimate. In this work, we use the Doppler velocity and density data obtained from the Coronal Multichannel Polarimeter (CoMP) on 2016 October 14 to obtain the global map of the coronal magnetic field using Bayesian inference. Two priors are used for plasma density, viz Gaussian and uniform distributions. Bayesian inference provides us with the probability distribution for the magnetic field strength at each location from 1.05 to 1.35 . A comparison between the magnetic field obtained using simple inversion and Bayesian inference is also drawn. We find that the values obtained using simple inversion do not always match the maximum posterior estimates obtained using Bayesian inference. We find that the inferred values follow a power-law function for the radial variation of the coronal magnetic field, with the power-law indices for simple and Bayesian inversion being similar.
arXiv commentAccepted for publication in The Astrophysical Journal
References in corpus (25)
- emcee: The MCMC Hammer
- MHD Waves and Coronal Seismology: an overview of recent results
- Time-Distance Seismology of the Solar Corona with CoMP
- CHIANTI - an atomic database for emission lines - Paper XV: Version 9, improvements for the X-ray satellite lines
- On the nature of kink MHD waves in magnetic flux tubes
- Persistent Doppler shift oscillations observed with HINODE/EIS in the solar corona: spectroscopic signatures of Alfvenic waves and recurring upflows
- Global maps of the magnetic field in the solar corona
- Coronal Loop Oscillations Observed with AIA - Kink-Mode with Cross-Sectional and Density Oscillations
- Wave Heating of the Solar Atmosphere
- Solar coronal magnetic fields derived using seismology techniques applied to omnipresent sunspot waves
- A basal contribution from p-modes to the Alfvénic wave flux in the Sun's corona
- A global view of velocity fluctuations in the corona below 1.3 with CoMP
- Mapping the magnetic field in the solar corona through magnetoseismology
- Measuring the magnetic field of a trans-equatorial loop system using coronal seismology
- Nonlinear force-free models for the solar corona I. Two active regions with very different structure
- Bayesian Coronal Seismology
- Bayesian Magnetohydrodynamic Seismology of Coronal Loops
- Direct Estimates of the Solar Coronal Magnetic Field Using Contemporaneous Extreme-ultraviolet, Radio, and White-light Observations
- Magnetic braids in eruptions of a spiral structure in the solar atmosphere
- No unique solution to the seismological problem of standing kink MHD waves
- Transverse oscillations in a coronal loop triggered by a jet
- Comparison of damping mechanisms for transverse waves in solar coronal loops
- Bayesian evidence for a nonlinear damping model for coronal loop oscillations
- Inference of magnetic field strength and density from damped transverse coronal waves
- Inversion of physical parameters in solar atmospheric seismology