Multi-height probing of horizontal flows in the solar photosphere

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Kostić, Teodor, Milić, Ivan, Rempel, Matthias, Welsch, Brian T., Kazachenko, Maria D., Ramos, Andrés Asensio, Tremblay, Benoit
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866909988339843072
author Kostić, Teodor
Milić, Ivan
Rempel, Matthias
Welsch, Brian T.
Kazachenko, Maria D.
Ramos, Andrés Asensio
Tremblay, Benoit
author_facet Kostić, Teodor
Milić, Ivan
Rempel, Matthias
Welsch, Brian T.
Kazachenko, Maria D.
Ramos, Andrés Asensio
Tremblay, Benoit
contents We tested whether simultaneous spectropolarimetric imaging in two magnetically sensitive optical spectral lines, which probe two different layers of the solar atmosphere (the photosphere and the temperature minimum), can help constrain the depth variation of horizontal flows. We first tested the feasibility of our method using Fourier local correlation tracking (FLCT) to track physical quantities at different optical depths ($\logτ_{500}={-1,-2,-3,-4}$) in an atmosphere simulated with the MURaM code. We then inferred the horizontal distribution of the LOS magnetic field component from synthetic spectropolarimetric observations of Fe I 525.0 nm and Mg I b2 spectral lines, applied FLCT to the time sequence of these synthetic magnetograms, and compared our findings with the original height-dependent horizontal velocities. Tracking the LOS magnetic field component (which coincides with the vertical component at the disk center) yields horizontal velocities that, after appropriate temporal and spatial averaging, agree excellently with the horizontal component of the simulated velocities, both calculated at constant $τ_{500}$ surfaces, up to the temperature minimum ($\logτ_{500}=-3$). When tracking the temperature at constant $τ_{500}$ surfaces, this agreement already breaks down completely at the mid photosphere ($\logτ_{500}=-2$). Tracking the vertical component of the magnetic field inferred from synthetic observations of the Fe I 525.0 nm and the Mg I b2 spectral lines yields a satisfactory inference of the horizontal velocities in the mid-photosphere ($\logτ_{500}\approx-1$) and the temperature minimum ($\logτ_{500}\approx-3$), respectively. Our results indicate that high-spatial-resolution spectropolarimetric imaging in solar spectral lines can provide meaningful information about the horizontal plasma velocities over a range of heights.
format Preprint
id arxiv_https___arxiv_org_abs_2511_19048
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Multi-height probing of horizontal flows in the solar photosphere
Kostić, Teodor
Milić, Ivan
Rempel, Matthias
Welsch, Brian T.
Kazachenko, Maria D.
Ramos, Andrés Asensio
Tremblay, Benoit
Solar and Stellar Astrophysics
We tested whether simultaneous spectropolarimetric imaging in two magnetically sensitive optical spectral lines, which probe two different layers of the solar atmosphere (the photosphere and the temperature minimum), can help constrain the depth variation of horizontal flows. We first tested the feasibility of our method using Fourier local correlation tracking (FLCT) to track physical quantities at different optical depths ($\logτ_{500}={-1,-2,-3,-4}$) in an atmosphere simulated with the MURaM code. We then inferred the horizontal distribution of the LOS magnetic field component from synthetic spectropolarimetric observations of Fe I 525.0 nm and Mg I b2 spectral lines, applied FLCT to the time sequence of these synthetic magnetograms, and compared our findings with the original height-dependent horizontal velocities. Tracking the LOS magnetic field component (which coincides with the vertical component at the disk center) yields horizontal velocities that, after appropriate temporal and spatial averaging, agree excellently with the horizontal component of the simulated velocities, both calculated at constant $τ_{500}$ surfaces, up to the temperature minimum ($\logτ_{500}=-3$). When tracking the temperature at constant $τ_{500}$ surfaces, this agreement already breaks down completely at the mid photosphere ($\logτ_{500}=-2$). Tracking the vertical component of the magnetic field inferred from synthetic observations of the Fe I 525.0 nm and the Mg I b2 spectral lines yields a satisfactory inference of the horizontal velocities in the mid-photosphere ($\logτ_{500}\approx-1$) and the temperature minimum ($\logτ_{500}\approx-3$), respectively. Our results indicate that high-spatial-resolution spectropolarimetric imaging in solar spectral lines can provide meaningful information about the horizontal plasma velocities over a range of heights.
title Multi-height probing of horizontal flows in the solar photosphere
topic Solar and Stellar Astrophysics
url https://arxiv.org/abs/2511.19048