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The weak-field approximation implying linear relationship between Stokes $V/I$ and longitudinal magnetic field, $B_{\Vert}$, often suffers from saturation observed in strong magnetic field regions such as sunspot umbra. In this work, we…

Solar and Stellar Astrophysics · Physics 2021-11-22 Andrei Plotnikov , Alexander Kutsenko , Shanbin Yang , Haiqing Xu , Xianyong Bai , Hongqi Zhang , Kirill Kuzanyan

The method of solar magnetic field calibration for the filter-based magnetograph is normally the linear calibration method under weak-field approximation that cannot generate the strong magnetic field region well due to the magnetic…

Solar and Stellar Astrophysics · Physics 2021-02-10 Jingjing Guo , Xianyong Bai , Yuanyong Deng , Hui Liu , Jiaben Lin , Jiangtao Su , Xiao Yang , Kaifan Ji

In this paper, we try to improve the magnetogram calibration method of the Solar Magnetic Field Telescope (SMFT). The improved calibration process fits the observed full Stokes information, using six points on the profile of Fe {\i} 5324.18…

Solar and Stellar Astrophysics · Physics 2014-09-18 Xianyong Bai , Yuanyong Deng , Fei Teng , Jiangtao Su , Xinjie Mao , Guoping Wang

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

In the recent years, we have seen a rapidly growing number of stellar magnetic field detections for various types of stars. Many of these magnetic fields are estimated from spectropolarimetric observations (Stokes V) by using the so-called…

Solar and Stellar Astrophysics · Physics 2015-06-18 T. A. Carroll , K. G. Strassmeier

Early magnetographic observations indicated that magnetic field in the solar photosphere has unresolved small-scale structure. Near-infrared and optical data with extremely high spatial resolution show that these structures have scales of…

Solar and Stellar Astrophysics · Physics 2018-11-21 M. Gordovskyy. , S. Shelyag , P. K. Browning , V. G. Lozitsky

For filter-based magnetographs, the linear calibration method under the weak-field assumption is usually adopted; this leads to magnetic saturation effect in the regions with strong magnetic field. This article explores a new method to…

Instrumentation and Methods for Astrophysics · Physics 2020-02-07 JingJing Guo , XianYong Bai , YuanYong Deng , Hui Liu , JiaBen Lin , JiangTao Su , Xiao Yang , KaiFan Ji

Extrapolations of line-of-sight photospheric field measurements predict radial interplanetary magnetic field (IMF) strengths that are factors of ~2--4 too low. To address this "open flux problem,'' we reanalyze the magnetograph measurements…

Solar and Stellar Astrophysics · Physics 2022-10-05 Y. -M. Wang , R. K. Ulrich , J. W. Harvey

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

Different methods for simulating the effects of spatial resolution on magnetic field maps are compared, including those commonly used for inter-instrument comparisons. The investigation first uses synthetic data, and the results are…

Solar and Stellar Astrophysics · Physics 2011-06-27 KD Leka , G. Barnes

The Vector Spectromagnetograph (VSM) of the NSO's Synoptic Optical Long-Term Investigations of the Sun (SOLIS) facility is now operational and obtains the first-ever vector magnetic field measurements of the entire visible solar hemisphere.…

Astrophysics · Physics 2007-07-02 M. K. Georgoulis , N. -E. Raouafi , C. J Henney

The magnetic field plays a major role in governing the dynamics of the sun. Many interesting features like sunspots, flares, prominences, and Coronal Mass Ejections (CMEs) occur on its surface due to the dynamics associated with the…

Instrumentation and Methods for Astrophysics · Physics 2016-12-14 Souvik Bose

In young sun-like stars and field M dwarf stars, chromospheric and coronal magnetic activity indicators such as H$\alpha$, X-ray and radio emission are known to saturate with low Rossby number ($Ro \lesssim 0.1$), defined as the ratio of…

Solar and Stellar Astrophysics · Physics 2020-01-22 Philip S. Muirhead , Mark J. Veyette , Elisabeth R. Newton , Christopher A. Theissen , Andrew W. Mann

The Full-disk magnetograph is a main scientific payload onboard the Advanced Space based Solar Observatory (ASO-S/FMG) that through Stokes parameter observation to measures the vector magnetic field. The accuracy of magnetic-field values is…

Solar and Stellar Astrophysics · Physics 2023-12-04 S. Liu , J. T. Su , X. Y. Bai , Y. Y. Deng , J. Chen , Y. L. Song , X. F. Wang , H. Q. Xu , X. Yang

During the last decade, the FORS1 instrument of the ESO Very Large Telescope has been used to obtain low resolution circular polarized spectra for about 500 stars, with the aim of measuring their mean longitudinal magnetic fields. Magnetic…

Solar and Stellar Astrophysics · Physics 2015-05-30 S. Bagnulo , J. D. Landstreet , L. Fossati , O. Kochukhov

The MHD virial theorem may be used to estimate the magnetic energy of active regions based on vector magnetic fields measured at the photosphere or chromosphere. However, the virial estimate depends on the measured vector magnetic field…

Astrophysics · Physics 2009-11-13 M. S. Wheatland , T. R. Metcalf

Isochronous mass spectrometry (IMS) in storage rings is a successful technique for accurate mass measurements of short-lived nuclides with relative precision of about $10^{-5}-10^{-7}$. Instabilities of the magnetic fields in storage rings…

Magnetography using magnetic sensitive lines is regarded traditionally as the main instrument for measuring the magnetic field of the whole Sun. Full polarized Stockes parameters ($I$, $Q$, $U$, $V$) observed can be used to deduce the…

Solar and Stellar Astrophysics · Physics 2022-01-19 S. Liu , J. T. Su , X. Y. Bai , Y. Y Deng , J. Chen , Y. L. Song , X. F. Wang , H. Q. Xu , X. Yang

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

A spectral line inversion code, Very Fast Inversion of the Stokes Vector (VFISV), has been used since May 2010 to infer the solar atmospheric parameters from the spectropolarimetric observations taken by the Helioseismic and Magnetic Imager…

Solar and Stellar Astrophysics · Physics 2021-12-22 Ana Belén Griñón-Marín , Adur Pastor Yabar , Yang Liu , J. Todd Hoeksema , Aimee Norton
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