Enregistré dans:
| Auteurs principaux: | , , |
|---|---|
| Format: | Preprint |
| Publié: |
2025
|
| Sujets: | |
| Accès en ligne: | https://arxiv.org/abs/2503.12498 |
| Tags: |
Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
|
| _version_ | 1866913738787913728 |
|---|---|
| author | Siu-Tapia, A. L. Rubio, L. R. Bellot Suárez, D. Orozco |
| author_facet | Siu-Tapia, A. L. Rubio, L. R. Bellot Suárez, D. Orozco |
| contents | Aims. We examined the capabilities of methods based on the weak-field approximation and line bisectors to extract fast and reliable information about the height stratification of the magnetic field and line-of-sight velocities, respectively, from high spatial resolution observations of the Mg I b$_2$ line at 5173 Å. Methods. The Mg I b$_2$ line was analyzed alongside the Fe I 6173 Å line to help constrain the physical conditions of the photosphere. Additionally, we present the first high-resolution inversions of the Mg I b$_2$ line under nonlocal thermodynamic equilibrium (NLTE) conditions conducted over a large field of view using a full-Stokes multiline approach. To determine the optimal inversion strategy, we performed several tests on the Mg I b$_2$ line using the Fourier Transform Spectrometer atlas profile before applying it to our observations. Results. The good correlations between the traditional methods and the NLTE inversions indicate that the weak-field approximation is generally a reliable diagnostic tool at moderate field strengths for the rapid inference of the longitudinal magnetic field from the Mg I b$_2$ line. In contrast, line bisectors exhibit poorer correlations with the NLTE inferred plasma velocities, suggesting that they might not be suitable for deriving velocity gradients from the Mg I b$_2$ line. Furthermore, to accurately derive the thermodynamic properties of the solar atmosphere from this line, the more complex, and time-consuming, NLTE Stokes inversions are necessary. This work also provides observational evidence of the existence of low-lying canopies expanding above bright magnetic structures and pores near the low chromosphere. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2503_12498 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Diagnosing the solar atmosphere through the Mg I b$_2$ 5173 Å line. I. Nonlocal thermodynamic equilibrium inversions versus traditional inferences Siu-Tapia, A. L. Rubio, L. R. Bellot Suárez, D. Orozco Solar and Stellar Astrophysics Aims. We examined the capabilities of methods based on the weak-field approximation and line bisectors to extract fast and reliable information about the height stratification of the magnetic field and line-of-sight velocities, respectively, from high spatial resolution observations of the Mg I b$_2$ line at 5173 Å. Methods. The Mg I b$_2$ line was analyzed alongside the Fe I 6173 Å line to help constrain the physical conditions of the photosphere. Additionally, we present the first high-resolution inversions of the Mg I b$_2$ line under nonlocal thermodynamic equilibrium (NLTE) conditions conducted over a large field of view using a full-Stokes multiline approach. To determine the optimal inversion strategy, we performed several tests on the Mg I b$_2$ line using the Fourier Transform Spectrometer atlas profile before applying it to our observations. Results. The good correlations between the traditional methods and the NLTE inversions indicate that the weak-field approximation is generally a reliable diagnostic tool at moderate field strengths for the rapid inference of the longitudinal magnetic field from the Mg I b$_2$ line. In contrast, line bisectors exhibit poorer correlations with the NLTE inferred plasma velocities, suggesting that they might not be suitable for deriving velocity gradients from the Mg I b$_2$ line. Furthermore, to accurately derive the thermodynamic properties of the solar atmosphere from this line, the more complex, and time-consuming, NLTE Stokes inversions are necessary. This work also provides observational evidence of the existence of low-lying canopies expanding above bright magnetic structures and pores near the low chromosphere. |
| title | Diagnosing the solar atmosphere through the Mg I b$_2$ 5173 Å line. I. Nonlocal thermodynamic equilibrium inversions versus traditional inferences |
| topic | Solar and Stellar Astrophysics |
| url | https://arxiv.org/abs/2503.12498 |