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The Very Fast Inversion of the Stokes Vector (VFISV) is a Milne-Eddington spectral line inversion code used to determine the magnetic and thermodynamic parameters of the solar photosphere from observations of the Stokes vector in the 6173 A…

Solar and Stellar Astrophysics · Physics 2014-03-17 R. Centeno , J. Schou , K. Hayashi , A. Norton , J. T. Hoeksema , Y. Liu , K. D. Leka , G. Barnes

In this paper we describe in detail the implementation and main properties of a new inversion code for the polarized radiative transfer equation (VFISV: Very Fast inversion of the Stokes vector). VFISV will routinely analyze pipeline data…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 J. M. Borrero , S. Tomczyk , M. Kubo , H. Socas-Navarro , J. Schou , S. Couvidat , R. Bogart

The Helioseismic and Magnetic Imager (HMI) began near-continuous full-disk solar measurements on 1 May 2010 from the Solar Dynamics Observatory (SDO). An automated processing pipeline keeps pace with observations to produce observable…

The Helioseismic and Magnetic Imager (HMI) onboard NASA's Solar Dynamics Observatory (SDO) produces estimates of the photospheric magnetic field which are a critical input to many space weather modelling and forecasting systems. The…

The Helioseismic and Magnetic Imager (HMI) has just started producing data that will help determine what the sources and mechanisms of variability in the Sun's interior are. The instrument measures the Doppler shift and the polarization of…

Solar and Stellar Astrophysics · Physics 2010-12-20 Rebecca Centeno , Steve Tomczyk , Juan Manuel Borrero , Sebastien Couvidat , Keiji Hayashi , Todd Hoeksema , Yang Liu , Jesper Schou

We investigate the accuracy to which we can retrieve the solar photospheric magnetic field vector using the Helioseismic and Magnetic Imager (HMI) that will fly onboard of the Solar Dynamics Observatory (SDO) by inverting simulated HMI…

Astrophysics · Physics 2009-11-11 J. M. Borrero , S. Tomczyk , A. Norton , T. Darnell , J. Schou , P. Scherrer , R. Bush , Y. Liu

The Helioseismic and Magnetic Imager (HMI), on board the Solar Dynamics Observatory (SDO), will begin data acquisition in 2008. It will provide the first full disk, high temporal cadence observations of the full Stokes vector with a 0.5 arc…

Astrophysics · Physics 2007-05-23 J. M. Borrero , S. Tomczyk , A. Norton , T. Darnell , J. Schou , P. Scherrer , R. Bush , Y. Lui

Spectral line inversion codes are tools used to interpret spectropolarimetric data; in general, their function is to analyze a set of observed Stokes profiles, and infer the physical properties of the line-formation region in which the…

Instrumentation and Methods for Astrophysics · Physics 2017-07-04 Brian J. Harker

Full-disk measurements of the solar magnetic field by the Helioseismic and Magnetic Imager (HMI) are often used for magnetic field extrapolations, but its limited spatial and spectral resolution can lead to significant errors. We compare…

Solar and Stellar Astrophysics · Physics 2024-11-27 C. Beck , A. Prasad , Q. Hu , M. S. Yalim , S. Gosain , D. P. Choudhary

Since May 1, 2010, we have been able to study (almost) continuously the vector magnetic field in the Sun, thanks to two space-based observatories: the Solar Dynamics Observatory (SDO) and Hinode. Both are equipped with instruments able to…

Solar and Stellar Astrophysics · Physics 2018-01-24 Alberto Sainz Dalda

With the advent of next generation high resolution telescopes, our understanding of how the magnetic field is organized in the internetwork (IN) photosphere is likely to advance.We aim to evaluate the extent to which we can retrieve…

Solar and Stellar Astrophysics · Physics 2021-10-04 R. J. Campbell , S. Shelyag , C. Quintero Noda , M. Mathioudakis , P. H. Keys , A. Reid

Inversion techniques applied to the radiative transfer equation for polarized light are capable of inferring the physical parameters in the solar atmosphere (temperature $T$, magnetic field ${\bf B}$, and line-of-sight velocity $v_{\rm…

Solar and Stellar Astrophysics · Physics 2021-04-07 J. M. Borrero , A. Pastor Yabar , B. Ruiz Cobo

The topic of magnetic field diagnostics with the Zeeman effect is currently vividly discussed. There are some testable inversion codes available to the spectropolarimetry community and their application allowed for a better understanding of…

Solar and Stellar Astrophysics · Physics 2016-11-29 M. Derouich

An accurate measurement of magnetic field is very important for understanding the formation and evolution of solar magnetic fields. Currently there are two types of solar magnetic field measurement instruments: the filter-based…

Solar and Stellar Astrophysics · Physics 2023-10-10 Mei Zhang , Haocheng Zhang , Chengqing Jiang

Spectral inversion codes are powerful tools to analyze spectropolarimetric observations, and they provide important diagnostics of solar magnetic fields. Inversion codes differ by numerical procedures, approximations of the atmospheric…

Solar and Stellar Astrophysics · Physics 2015-06-04 H. Balthasar , M. L. Demidov

The goal of this study is to explore a novel method for the solar photospheric magnetic field diagnostics using Stokes V widths of different magnetosensitive Fe~I spectral lines. We calculate Stokes I and V profiles of several Fe I lines…

Solar and Stellar Astrophysics · Physics 2020-01-29 M. Gordovskyy , S. Shelyag , P. K. Browning , V. G. Lozitsky

Stokes inversion codes are crucial in returning properties of the solar atmosphere, such as temperature and magnetic field strength. However, the success of such algorithms to return reliable values can be hindered by the presence of…

Solar and Stellar Astrophysics · Physics 2021-01-20 P. H. Keys , O. Steiner , G. Vigeesh

We aim at demonstrating the capabilities of a newly developed method for determining electric currents in the solar photosphere. We employ three-dimensional radiative magneto-hydrodynamic (MHD) simulations to produce synthetic Stokes…

Solar and Stellar Astrophysics · Physics 2021-12-22 A. Pastor Yabar , J. M. Borrero , C. Quintero Noda , B. Ruiz Cobo

The spectral window, containing Fraunhofer lines formed in the solar photosphere, around the magnetically sensitive Cr I lines at 5780.9, 5781.1, 5781.7, 5783.0, and 5783.8 \r{A}, with Land\'e g-factors between 1.6 and 2.5, is explored. The…

In a previous paper, we argued that the inversion of Stokes profiles applied to spectropolarimetric observations of the solar internetwork yield unrealistically large values of the inclination of the magnetic field vector ($\gamma$). This…

Solar and Stellar Astrophysics · Physics 2015-06-11 J. M. Borrero , P. Kobel
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