English
Related papers

Related papers: Sparse reconstruction of electric fields from radi…

200 papers

Modern radio telescopes are extremely sensitive to plasma on the line of sight from a radio source to the antenna. Plasmas in the corona and solar wind produce measurable changes in the radio wave amplitude and phase, and the phase…

Astrophysics · Physics 2009-11-13 Steven R. Spangler , Catherine A. Whiting

Next-generation spectro-polarimetric broadband surveys will probe cosmic magnetic fields in unprecedented detail, using the magneto-optical effect known as Faraday rotation. However, non-parametric methods such as RMCLEAN can introduce…

Instrumentation and Methods for Astrophysics · Physics 2021-12-08 Luke Pratley , Melanie Johnston-Hollitt , Bryan M. Gaensler

Deriving the strength and direction of the three-dimensional (3D) magnetic field in the solar atmosphere is fundamental for understanding its dynamics. Volume information on the magnetic field mostly relies on coupling 3D reconstruction…

Solar and Stellar Astrophysics · Physics 2019-06-05 K. Dalmasse , A. Savcheva , S. E. Gibson , Y. Fan , D. W. Nychka , N. Flyer , N. Mathews , E. E. DeLuca

The inverse problem for electromagnetic field produced by arbitrary altered charge distribution in dipole approximation is solved. The charge distribution is represented by its dipole moment. It is assumed that the spectral properties of…

Classical Physics · Physics 2015-05-06 V. Epp , J. G. Janz

Magnetic flux synoptic charts are critical for reliable modeling of the corona and heliosphere. Until now, however, these charts were provided without any estimate of uncertainties. The uncertainties are due to instrumental noise in the…

Solar and Stellar Astrophysics · Physics 2015-06-18 L. Bertello , A. A. Pevtsov , G. J. D. Petrie , D. Keys

The coronal magnetic field, despite its overwhelming importance to the physics and dynamics of the corona, has only rarely been measured. Here, the electron density maps derived from images acquired during the total solar eclipse of August…

Solar and Stellar Astrophysics · Physics 2023-03-29 Alessandro Bemporad

The autocorrelation function and similarly the Fourier-power spectrum of a rotation measure (RM) map of an extended background radio source can be used to measure components of the magnetic autocorrelation and power-spectrum tensor within a…

Astrophysics · Physics 2011-05-23 Torsten A. Ensslin , Corina Vogt

The heliospheric magnetic field is of pivotal importance in solar and space physics. The field is rooted in the Sun's photosphere, where it has been observed for many years. Global maps of the solar magnetic field based on full disk…

Solar and Stellar Astrophysics · Physics 2017-10-18 J. A. Linker , R. M. Caplan , C. Downs , P Riley , Z Mikic , R. Lionello , C. J. Henney , C. N. Arge , Y. Liu , M. L. Derosa , A. Yeates , M. J. Owens

Solar magnetic fields are closely related to various physical phenomena on the sun, which can be extrapolated with different models from photospheric magnetograms. However, the Open Flux Problem (OFP), the underestimation of the magnetic…

Solar and Stellar Astrophysics · Physics 2024-05-30 Guanglu Shi , Li Feng , Beili Ying , Shuting Li , Weiqun Gan

Magnetic fields in the solar corona are responsible for a wide range of phenomena. However, any direct measurements of the coronal magnetic fields are very difficult due to lack of suitable spectral lines, weak magnetic fields, and high…

Solar and Stellar Astrophysics · Physics 2013-10-28 P. Vemareddy , A. Ambastha , T. Wiegelmann

Background: Calculation of the electric field induced by transcranial magnetic stimulation (TMS) in the brain requires accurate models of the stimulation coils. Reconstructing models from the measured magnetic fields of coils so far worked…

Other Quantitative Biology · Quantitative Biology 2021-12-30 Kristoffer Hougaard Madsen , Maria Drakaki , Axel Thielscher

Faraday complexity describes whether a spectropolarimetric observation has simple or complex magnetic structure. Quickly determining the Faraday complexity of a spectropolarimetric observation is important for processing large, polarised…

Instrumentation and Methods for Astrophysics · Physics 2021-07-01 M. J. Alger , J. D. Livingston , N. M. McClure-Griffiths , J. L. Nabaglo , O. I. Wong , C. S. Ong

Understanding structures and evolutions of the magnetic fields and plasma in multiple layers on the Sun is very important. A force-free magnetic field which is an accurate approximation of the solar corona due to the low plasma $\beta$ has…

Solar and Stellar Astrophysics · Physics 2022-03-30 Xiaoshuai Zhu , Thomas Neukirch , Thomas Wiegelmann

Magnetic field strengths in objects ranging from HII regions to cosmological large scale structure can be estimated using dense grids of Rotation Measures (RMs) from polarized background radio structures. Upcoming surveys on the SKA and its…

Astrophysics of Galaxies · Physics 2019-01-29 Lawrence Rudnick

Radio synchrotron emission, its polarization and its Faraday rotation are powerful tools to study the strength and structure of interstellar magnetic fields. In the Milky Way, Faraday rotation of the polarized emission from pulsars and…

Instrumentation and Methods for Astrophysics · Physics 2010-08-24 R. Beck

The Potential Field Source Surface (PFSS) model is the most used approach for extrapolating the global coronal magnetic field, offering efficiency and strong performance at large scales. However, PFSS assumes a potential coronal field, so…

Solar and Stellar Astrophysics · Physics 2026-03-23 C. Antonio , I. Chifu , R. Gafeira , J. J. G. Lima

The potential field source surface (PFSS) equations are commonly used to model the coronal magnetic field of the Sun and other stars. As with any computational model, solving equations using a numerical scheme introduces errors due to…

Solar and Stellar Astrophysics · Physics 2022-01-20 David Stansby , Daniel Verscharen

In this article, we present the result of the research, which was directed to gaining electromotive voltage in a theoretically pure way. We designed and built a brushless generator that simulates a homogenised magnetic field and should…

Classical Physics · Physics 2018-02-22 Pavol Ivana , Marika Ivanova

For the extrapolation of magnetic fields into the solar corona from measurements taken in the photosphere (or chromosphere) force-free magnetic fields are typically used. This does not take into account that the lower layers of the solar…

Solar and Stellar Astrophysics · Physics 2020-01-08 Thomas Neukirch , Thomas Wiegelmann

Knowledge of the structure of the coronal magnetic field is important for our understanding of many solar activity phenomena, e.g. flares and CMEs. However, the direct measurement of coronal magnetic fields is not possible with present…

Astrophysics · Physics 2020-01-29 T. Wiegelmann , T. Neukirch