Spectropolarimetric observations of the Ca II 8498 A and 8542 A lines in the quiet Sun

Abstract

The Ca II infrared triplet is one of the few magnetically sensitive chromospheric lines available for ground-based observations. We present spectropolarimetric observations of the 8498 A and 8542 A lines in a quiet Sun region near a decaying active region and compare the results with a simulation of the lines in a high plasma-beta regime. Cluster analysis of Stokes V profile pairs shows that the two lines, despite arguably being formed fairly close, often do not have similar shapes. In the network, the local magnetic topology is more important in determining the shapes of the Stokes V profiles than the phase of the wave, contrary to what our simulations show. We also find that Stokes V asymmetries are very common in the network, and the histograms of the observed amplitude and area asymmetries differ significantly from the simulation. Both the network and internetwork show oscillatory behavior in the Ca II lines. It is stronger in the network, where shocking waves, similar to those in the high-beta simulation, are seen and large self-reversals in the intensity profiles are common.

arXiv comment23 pages, 17 figures, accepted to ApJ some figures are low-res, for high-res email [email protected]

References in corpus (8)

• Solar Atmospheric Oscillations and the Chromospheric Magnetic Topology
• SPINOR: Visible and Infrared Spectro-Polarimetry at the National Solar Observatory
• The Three-Dimensional Structure of a Sunspot Magnetic Field
• Quiet Sun magnetic fields from simultaneous inversions of visible and infrared spectropolarimetric observations
• Zero-Field Dichroism in the Solar Chromosphere
• Signatures of Incomplete Paschen-Back Splitting in the Polarization Profiles of the He I 10830 multiplet
• Milne-Eddington inversions of the He I 10830 Å Stokes profiles: Influence of the Paschen-Back effect
• Simulation of quiet Sun waves in the Ca II infrared triplet

Cited by in corpus (28)

• Inversion of the radiative transfer equation for polarized light
• The solar chromosphere at high resolution with IBIS. I. New insights from the Ca II 854.2 nm line
• The European Solar Telescope
• Radiative diagnostics in the solar photosphere and chromosphere
• Identifying typical Mg II flare spectra using machine learning
• Heating of the magnetic chromosphere: observational constraints from Ca II 8542 spectra
• Spectropolarimetric inversions of the Ca ii 8542 Å line in a M-class solar flare
• Synthetic observations of wave propagation in a sunspot umbra
• Chromospheric polarimetry through multi-line observations of the 850 nm spectral region
• Spectroscopic inversions of the Ca ii 8542 Å line in a C-class solar flare
• The energy of waves in the photosphere and lower chromosphere: III. Inversion setup for Ca II H spectra in local thermal equilibrium
• Non-LTE inversions of a confined X2.2 flare: I. Vector magnetic field in the photosphere and chromosphere
• Determining the dynamics and magnetic fields in He I 10830 Å during a solar filament eruption
• Active region chromospheric magnetic fields
• Fabry-Perot versus slit spectropolarimetry of pores and active network. Analysis of IBIS and Hinode data
• Chromospheric polarimetry through multi-line observations of the 850 nm spectral region II: A magnetic flux tube scenario
• Solar surges related to UV bursts: Characterization through k-means, inversions and density diagnostics
• Accurately constraining velocity information from spectral imaging observations using machine learning techniques
• Spectroscopy at the solar limb: I. Average off-limb profiles and Doppler shifts of Ca II H
• Ubiquitous hundred-Gauss magnetic fields in solar spicules
• Shape-based clustering of synthetic Stokes profiles using k-means and k-Shape
• First Observation of Chromospheric Waves in a Sunspot by DKIST/ViSP: The Anatomy of an Umbral Flash
• Semi-empirical models of spicule from inversion of Ca II 8542 Å line
• A chromospheric conundrum?
• Using Multiple Instance Learning for Explainable Solar Flare Prediction
• Stratification of canopy magnetic fields in a plage region. Constraints from a spatially-regularized weak-field approximation method
• The magnetic sensitivity of the Ca II H and K lines
• The dependence of the magnetism of a near-limb sunspot on height