تقرير
The potential of many-line inversions of photospheric spectropolarimetric data in the visible and near UV
| العنوان: | The potential of many-line inversions of photospheric spectropolarimetric data in the visible and near UV |
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| المؤلفون: | Riethmüller, T. L., Solanki, S. K. |
| المصدر: | A&A 622, A36 (2019) |
| سنة النشر: | 2018 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Instrumentation and Methods for Astrophysics |
| الوصف: | Our knowledge of the lower solar atmosphere is mainly obtained from spectropolarimetric observations, which are often carried out in the red or infrared spectral range and almost always cover only a single or a few spectral lines. Here we compare the quality of Stokes inversions of only a few spectral lines with many-line inversions. We investigate the feasibility of spectropolarimetry in the short-wavelength range, 3000 \AA{} - 4300 \AA{}, where the line density but also the photon noise are considerably higher than in the red, so that many-line inversions could be particularly attractive in that wavelength range. This is also timely because this wavelength range will be the focus of a new spectropolarimeter in the third science flight of the balloon-borne solar observatory SUNRISE. For an ensemble of MHD atmospheres we synthesize exemplarily spectral regions around 3140 \AA{}, 4080 \AA{}, and 6302 \AA{}. The spectral coverage is chosen such that at a spectral resolving power of 150000 the spectra can be recorded by a 2K detector. The synthetic Stokes profiles are degraded with a typical photon noise and afterwards inverted. The atmospheric parameters of the inversion of noisy profiles are compared with the inversion of noise-free spectra. We find that significantly more information can be obtained from many-line inversions than from a traditionally used inversion of only a few spectral lines. We further find that information on the upper photosphere can be significantly more reliably obtained at short wavelengths. In the mid and lower photosphere, the many-line approach at 4080 \AA{} provides equally good results as the many-line approach at 6302 \AA{} for the magnetic field strength and the LOS velocity, while the temperature determination is even more precise by a factor of three. We conclude that many-line spectropolarimetry should be the preferred option in the future. Comment: Accepted for publication in Astronomy & Astrophysics |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1051/0004-6361/201833379 |
| URL الوصول: | http://arxiv.org/abs/1812.03757 |
| رقم الأكسشن: | edsarx.1812.03757 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1051/0004-6361/201833379 |
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