0000000000230173
AUTHOR
Laurent Gizon
showing 16 related works from this author
COMPARISON BETWEEN Mg IIkAND Ca II H IMAGES RECORDED BY SUNRISE/SuFI
2014
We present a comparison of high-resolution images of the solar surface taken in the Mg II k and Ca II H channels of the Filter Imager on the balloon-borne solar observatory SUNRISE. The Mg and Ca lines are sampled with 0.48 nm and 0.11 nm wide filters, respectively. The two channels show remarkable qualitative and quantitative similarities in the quiet Sun, in an active region plage and during a small flare. However, the Mg filtergrams display 1.4-1.7 times higher intensity contrast and appear more smeared and smoothed in the quiet Sun. In addition, the fibrils in a plage are wider. Although the exposure time is 100 times longer for Mg images, the evidence suggests that these differences ca…
Photospheric response to an ellerman bomb-like event—an analogy of Sunrise/IMaX observations and MHD simulations
2017
S. Danilovic et. al.
Power spectrum of turbulent convection in the solar photosphere
2020
The solar photosphere provides us with a laboratory for understanding turbulence in a layer where the fundamental processes of transport vary rapidly and a strongly superadiabatic region lies very closely to a subadiabatic layer. Our tools for probing the turbulence are high-resolution spectropolarimetric observations such as have recently been obtained with the two balloon-borne SUNRISE missions, and numerical simulations. Our aim is to study photospheric turbulence with the help of Fourier power spectra that we compute from observations and simulations. We also attempt to explain some properties of the photospheric overshooting flow with the help of its governing equations and simulations…
The polarimetric and helioseismic imager on solar orbiter
2020
This paper describes the Polarimetric and Helioseismic Imager on the Solar Orbiter mission (SO/PHI), the first magnetograph and helioseismology instrument to observe the Sun from outside the Sun-Earth line. It is the key instrument meant to address the top-level science question: How does the solar dynamo work and drive connections between the Sun and the heliosphere? SO/PHI will also play an important role in answering the other top-level science questions of Solar Orbiter, as well as hosting the potential of a rich return in further science. SO/PHI measures the Zeeman effect and the Doppler shift in the FeI 617.3nm spectral line. To this end, the instrument carries out narrow-band imaging…
Oscillations on Width and Intensity of Slender Ca ii H Fibrils from Sunrise/SuFI
2017
R. Gafeira et. al.
The Second Flight of the Sunrise Balloon-borne Solar Observatory: Overview of Instrument Updates, the Flight, the Data, and First Results
2017
S. K. Solanki et. al.
Morphological Properties of Slender Ca ${\rm{II}}$ H Fibrils Observed by Sunrise II
2017
R. Gafeira et. al.
Transverse Oscillations in Slender Ca II H Fibrils Observed with Sunrise/SuFI
2016
S. Jafarzadeh et. al.
A new MHD-assisted Stokes inversion technique
2016
©2017 The American Astronomical Society. All rights reserved. We present a new method of Stokes inversion of spectropolarimetric data and evaluate it by taking the example of a Sunrise/IMaX observation. An archive of synthetic Stokes profiles is obtained by the spectral synthesis of state-of-the-art magnetohydrodynamics (MHD) simulations and a realistic degradation to the level of the observed data. The definition of a merit function allows the archive to be searched for the synthetic Stokes profiles that best match the observed profiles. In contrast to traditional Stokes inversion codes, which solve the Unno–Rachkovsky equations for the polarized radiative transfer numerically and fit the …
Solar Coronal Loops Associated with Small-scale Mixed Polarity Surface Magnetic Fields
2017
L. P. Chitta et. al.
Helioseismology with Solar Orbiter
2014
The Solar Orbiter mission, to be launched in July 2017, will carry a suite of remote sensing and in-situ instruments, including the Polarimetric and Helioseismic Imager (PHI). PHI will deliver high-cadence images of the Sun in intensity and Doppler velocity suitable for carrying out novel helioseismic studies. The orbit of the Solar Orbiter spacecraft will reach a solar latitude of up to 21 deg (up to 34 deg by the end of the extended mission) and thus will enable the first local helioseismology studies of the polar regions. Here we consider an array of science objectives to be addressed by helioseismology within the baseline telemetry allocation (51 Gbit per orbit, current baseline) and wi…
Slender Ca II H fibrils mapping magnetic fields in the low solar chromosphere
2017
S. Jafarzadeh et. al.
Moving Magnetic Features around a Pore
2017
A. J. Kaithakkal et. al.
Spectropolarimetric evidence for a siphon flow along an emerging magnetic flux tube
2016
©2017 The American Astronomical Society. All rights reserved.We study the dynamics and topology of an emerging magnetic flux concentration using high spatial resolution spectropolarimetric data acquired with the Imaging Magnetograph eXperiment on board the sunrise balloon-borne solar observatory. We obtain the full vector magnetic field and the line of sight (LOS) velocity through inversions of the Fe i line at 525.02 nm with the SPINOR code. The derived vector magnetic field is used to trace magnetic field lines. Two magnetic flux concentrations with different polarities and LOS velocities are found to be connected by a group of arch-shaped magnetic field lines. The positive polarity footp…
Maximum Entropy Limit of Small-scale Magnetic Field Fluctuations in the Quiet Sun
2017
The observed magnetic field on the solar surface is characterized by a very complex spatial and temporal behavior. Although feature-tracking algorithms have allowed us to deepen our understanding of this behavior, subjectivity plays an important role in the identification and tracking of such features. In this paper, we continue studies Gorobets, A. Y., Borrero, J. M., & Berdyugina, S. 2016, ApJL, 825, L18 of the temporal stochasticity of the magnetic field on the solar surface without relying either on the concept of magnetic features or on subjective assumptions about their identification and interaction. We propose a data analysis method to quantify fluctuations of the line-of-sight …
Kinematics of Magnetic Bright Features in the Solar Photosphere
2016
S. Jafarzadeh et. al.