Spectropolarimetric investigation of magnetohydrodynamic wave modes in the photosphere: First results from PHI on board Solar Orbiter

Abstract

In November 2021, Solar Orbiter started its nominal mission phase. The remote-sensing instruments on board the spacecraft acquired scientific data during three observing windows surrounding the perihelion of the first orbit of this phase. The aim of the analysis is the detection of magnetohydrodynamic (MHD) wave modes in an active region by exploiting the capabilities of spectropolarimetric measurements. The High Resolution Telescope (HRT) of the Polarimetric and Helioseismic Imager (SO/PHI) on board the Solar Orbiter acquired a high-cadence data set of an active region. This is studied in the paper. B-$\omega$ and phase-difference analyses are applied on line-of-sight velocity and circular polarization maps and other averaged quantities. We find that several MHD modes at different frequencies are excited in all analysed structures. The leading sunspot shows a linear dependence of the phase lag on the angle between the magnetic field and the line of sight of the observer in its penumbra. The magnetic pore exhibits global resonances at several frequencies, which are also excited by different wave modes. The SO/PHI measurements clearly confirm the presence of magnetic and velocity oscillations that are compatible with one or more MHD wave modes in pores and a sunspot. Improvements in modelling are still necessary to interpret the relation between the fluctuations of different diagnostics.

References in corpus (40)

• The Solar Orbiter mission -- Science overview
• The Helioseismic and Magnetic Imager (HMI) Vector Magnetic Field Pipeline: Overview and Performance
• The FIP and Inverse FIP Effects in Solar and Stellar Coronae
• The Imaging Magnetograph eXperiment (IMaX) for the Sunrise balloon-borne solar observatory
• Coronal heating by MHD waves
• The Polarimetric and Helioseismic Imager on Solar Orbiter
• Multiwavelength studies of MHD waves in the solar chromosphere: An overview of recent results
• Inversion of the radiative transfer equation for polarized light
• Properties of Magneto-Hydrodynamic Waves in the Solar Photosphere with Hinode
• Magneto-acoustic waves in sunspots: first results from a new 3D nonlinear magnetohydrodynamic code
• The Solar Orbiter Science Activity Plan: translating solar and heliospheric physics questions into action
• Alfvén Wave Dissipation in the Solar Chromosphere
• Observations of sausage modes in magnetic pores
• On the Formation Height of the SDO/HMI Fe 6173 Doppler Signal
• Structure and Dynamics of Isolated Internetwork Ca II H Bright Points Observed by Sunrise
• The usefulness of analytic response functions
• Photospheric observations of surface and body modes in solar magnetic pores
• Waves in the lower solar atmosphere: the dawn of next-generation solar telescopes
• MHD wave transmission in the Sun's atmosphere
• Transverse Oscillations in Slender Ca II H Fibrils Observed with Sunrise/SuFI
• High-frequency Oscillations in Small Magnetic Elements Observed with Sunrise/SuFI
• An Inside Look at Sunspot Oscillations with Higher Azimuthal Wavenumbers
• Dynamics of the solar atmosphere above a pore with a light bridge
• Unnoticed magnetic field oscillations in the very quiet Sun revealed by Sunrise/IMaX
• Alfvenic Perturbations in a Sunspot Chromosphere Linked to Fractionated Plasma in the Corona
• Magnetic field variations associated with umbral flashes and penumbral waves
• Internal Gravity Waves in the Magnetized Solar Atmosphere. I. Magnetic Field Effects
• Oscillations on width and intensity of slender Ca II H fibrils from Sunrise/SuFI
• Propagating Spectropolarimetric Disturbances in a Large Sunspot
• 3D simulations of realistic power halos in magneto-hydrostatic sunspot atmospheres: linking theory and observation
• The Propagation of Coherent Waves Across Multiple Solar Magnetic Pores
• A novel approach to identify resonant MHD wave modes in solar pores and sunspot umbrae: $B-\omega$ analysis
• The small-scale structure of photospheric convection retrieved by a deconvolution technique applied to Hinode/SP data
• The non-LTE formation of the Fe I 6173 A line in the solar atmosphere
• Accuracy analysis of the on-board data reduction pipeline for the Polarimetric and Helioseismic Imager on the Solar Orbiter mission
• Magnetic fields inferred by Solar Orbiter: A comparison between SO/PHI-HRT and SDO/HMI
• Stokes Diagnostics of Magneto-Acoustic Wave Propagation in the Magnetic Network on the Sun
• On the Origin of Magnetic Pertubations associated with the FIP effect
• Plasma composition measurements in an active region from Solar Orbiter/SPICE and Hinode/EIS
• The ratio of horizontal to vertical displacement in solar oscillations estimated from combined SO/PHI and SDO/HMI observations

Cited by in corpus (5)

• Wavefront error of PHI/HRT on Solar Orbiter at various heliocentric distances
• Sausage, kink, and fluting MHD wave modes identified in solar magnetic pores by Solar Orbiter/PHI
• Stereoscopic disambiguation of vector magnetograms: first applications to SO/PHI-HRT data
• Data-constrained 3D MHD Simulation of a Spiral Jet Caused by an Unstable Flux Rope Embedded in Fan-spine Configuration
• Solar photospheric velocities measured in space: a comparison between SO/PHI-HRT and SDO/HMI