Solar polarimetry through the K I lines at 770 nm

Abstract

We characterize the K I D1 & D2 lines in order to determine whether they could complement the 850 nm window, containing the Ca II infrared triplet lines and several Zeeman sensitive photospheric lines, that was studied previously. We investigate the effect of partial redistribution on the intensity profiles, their sensitivity to changes in different atmospheric parameters, and the spatial distribution of Zeeman polarization signals employing a realistic magnetohydrodynamic simulation. The results show that these lines form in the upper photosphere at around 500 km and that they are sensitive to the line of sight velocity and magnetic field strength at heights where neither the photospheric lines nor the Ca II infrared lines are. However, at the same time, we found that their sensitivity to the temperature essentially comes from the photosphere. Then, we conclude that the K I lines provide a complement to the lines in the 850 nm window for the determination of atmospheric parameters in the upper photosphere, especially for the line of sight velocity and the magnetic field.

arXiv comment10 pages, 9 figures, main journal publication

References in corpus (25)

• The Solar Optical Telescope for the Hinode Mission: An Overview
• The stellar atmosphere simulation code Bifrost
• CRISP Spectropolarimetric Imaging of Penumbral Fine Structure
• Chromospheric Anemone Jets as Evidence of Ubiquitous Reconnection
• Sunrise: instrument, mission, data and first results
• The Sunrise Mission
• A publicly available simulation of an enhanced network region of the Sun
• The second flight of the SUNRISE balloon-borne solar observatory: overview of instrument updates, the flight, the data and first results
• SPINOR: Visible and Infrared Spectro-Polarimetry at the National Solar Observatory
• Non-local thermodynamic equilibrium inversions from a 3D MHD chromospheric model
• On fibrils and field lines: The nature of H$\alpha$ fibrils in the solar chromosphere
• Spectropolarimetric capabilities of Ca II 8542 A line
• The quiet solar atmosphere observed and simulated in NaD1
• Magnetic Diagnostics of the Solar Chromosphere with the Mg II h-k Lines
• Partial redistribution in 3D non-LTE radiative transfer in solar atmosphere models
• Heating of the magnetic chromosphere: observational constraints from Ca II 8542 spectra
• The Hanle and Zeeman polarization signals of the solar Ca II 8542 Å line
• Chromospheric polarimetry through multi-line observations of the 850 nm spectral region
• The transfer of resonance line polarization with partial frequency redistribution in the general Hanle-Zeeman regime
• Quiet-Sun imaging asymmetries in NaI D1 compared with other strong Fraunhofer lines
• The transfer of resonance line polarization with partial frequency redistribution and J-state interference
• Ellerman bombs at high resolution. IV. Visibility in Na I and Mg I
• Expansion of magnetic flux concentrations: a comparison of Hinode SOT d ata and models
• Radiative transfer modeling of the enigmatic scattering polarization in the solar NaI D1 line
• Chromospheric Polarization in the Photospheric Solar Oxygen Infrared Triplet

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• Solar polarimetry in the K I $D_2$ line: A novel possibility for a stratospheric balloon
• SunnyNet: A neural network approach to 3D non-LTE radiative transfer
• Multi-Height Observations of Atmospheric Gravity Waves at Solar Disk Center
• Development of Fast and Precise Scan Mirror Mechanism for an Airborne Solar Telescope
• Multi-wavelength spectropolarimetric observations of AR13724 performed by GRIS
• Non-Local Thermodynamic Equilibrium inversions of the Si I 10827 A spectral line