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相关论文: Spectro-polarimetric observations of solar magneti…

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Strong, globally-organized magnetic fields are found for a small fraction of O, B, and A stars. At the same time, many theoretical and indirect observational studies suggested ubiquitous presence of weak localized magnetic fields at the…

太阳与恒星天体物理 · 物理学 2015-06-15 O. Kochukhov , N. Sudnik

We investigate the impact on Fe abundance determination of including magnetic flux in series of 3D radiation-MHD simulations of solar convection which we used to synthesize spectral intensity profiles corresponding to disc centre. A…

太阳与恒星天体物理 · 物理学 2015-06-11 D. Fabbian , F. Moreno-Insertis , E. Khomenko , Å. Nordlund

Aims. We use high-resolution spectropolarimetric observations in the Ca ii 8542 A line obtained with the SST to study the magnetic field in solar spicules. Methods. The equations that result from the application of the Weak Field…

太阳与恒星天体物理 · 物理学 2020-10-07 M. Kriginsky , R. Oliver , N. Freij , D. Kuridze , A. Asensio Ramos , P. Antolin

Judge et al. (2021) recently argued that a region of the solar spectrum in the near-UV between about 250 and 290 nm is optimal for studying magnetism in the solar chromosphere due to an abundance of Mg II, Fe II, and Fe I lines that sample…

太阳与恒星天体物理 · 物理学 2023-09-12 A. G. de Wijn , P. G. Judge , R. Ezzeddine , A. Sainz Dalda

Magnetic fields are expected to play an important role in accretion processes for circumstellar disks. Measuring the magnetic field morphology is difficult, especially since polarimetric (sub)millimeter continuum observations may not trace…

太阳与恒星天体物理 · 物理学 2020-09-30 Ian W. Stephens , Manuel Fernandez-Lopez , Zhi-Yun Li , Leslie W. Looney , Richard Teague

We report on spectropolarimetric observations of a near-IR line of Mn I located at 15262.702 A whose intensity and polarization profiles are very sensitive to the presence of hyperfine structure. A theoretical investigation of the magnetic…

The detailed investigation of the polar magnetic field and its time evolution is one of the major achievements of Hinode. Precise measurements of the polar magnetic field are essential for understanding the solar cycle, as they provide…

The standard methods of the magnetic field measurement, based on an analysis of the relation between the Stokes $V$-parameter and the first derivative of the total line profile intensity, were modified by applying a linear integral operator…

太阳与恒星天体物理 · 物理学 2015-06-15 A. F. Kholtygin

We study 7530 sunspot umbrae and pores measured by the Hinode Spectropolarimeter (SP) between November 2006 and November 2012. We primarily seek confirmation of the long term secular decrease in the mean magnetic field strength of sunspot…

太阳与恒星天体物理 · 物理学 2015-05-22 T. A. Schad

We present a magnetic-field surface map for both stellar components of the young visual binary ksi Boo AB (A: G8V, B: K5V). Employed are high resolution Stokes-V spectra obtained with the Potsdam Echelle Polarimetric and Spectroscopic…

太阳与恒星天体物理 · 物理学 2023-06-14 K. G. Strassmeier , T. A. Carroll , I. V. Ilyin

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…

太阳与恒星天体物理 · 物理学 2021-02-10 Jingjing Guo , Xianyong Bai , Yuanyong Deng , Hui Liu , Jiaben Lin , Jiangtao Su , Xiao Yang , Kaifan Ji

Millimeter-wavelength polarization measurements offer a promising method for probing the geometry of magnetic fields in circumstellar disks. Single dish observations and theoretical work have hinted that magnetic field geometries might be…

太阳与恒星天体物理 · 物理学 2015-06-15 A. M. Hughes , C. L. H. Hull , D. J. Wilner , R. L. Plambeck

We present the results of a statistical analysis of the Doppler shifts and the asymmetry parameters of V profiles of the Fe I 630.25 nm line produced by 2D MHD simulations of solar granulation. The realism of the simulations tested using…

太阳与恒星天体物理 · 物理学 2010-07-21 V. A. Sheminova

The Sun's spectrum varies with center-to-limb distance. This variation is governed by the underlying temperature-density structure of the solar atmosphere. To explore the spectrally resolved center-to-limb variation (CLV) we make use of two…

太阳与恒星天体物理 · 物理学 2014-12-24 Jan Stenflo

The contribution of the quiet Sun to solar irradiance variability, due either to changes of the solar effective temperature or to the presence of unresolved magnetic field, is still poorly understood. In this study we investigate spectral…

太阳与恒星天体物理 · 物理学 2015-06-12 Serena Criscuoli , Ilaria Ermolli , Han Uitenbroek , Fabrizio Giorgi

Submillimeter dust polarization measurements of a sample of 50 star-forming regions, observed with the SMA and the CSO covering pc-scale clouds to mpc-scale cores, are analyzed in order to quantify the magnetic field importance. The…

Proving the magnetic configuration of solar spicules has hitherto been difficult due to the lack of spatial resolution and image stability during off-limb ground-based observations. We report spectropolarimetric observations of spicules…

太阳与恒星天体物理 · 物理学 2015-04-21 D. Orozco Suarez , A. Asensio Ramos , J. Trujillo Bueno

Searches for exoplanets with radial velocity techniques are increasingly sensitive to stellar activity. It is therefore crucial to characterize how this activity influences radial velocity measurements in their study of the detectability of…

太阳与恒星天体物理 · 物理学 2015-05-19 Nadège Meunier , Anne-Marie Lagrange , Morgan Desort

We present spectro-polarimetric observations of Inter-Network magnetic fields at the solar disk center. A Fabry-Perot spectrometer was used to scan the two Fe I lines at 6301.5 A and 6302.5 A. High spatial resolution (0.5") magnetograms…

天体物理学 · 物理学 2009-11-07 I. Dominguez Cerdena , F. Kneer , J. Sanchez Almeida

We measured the center-to-limb variation of the brightness temperature, $T_b$, from ALMA full-disk images at two frequencies and inverted the solution of the transfer equation to obtain the electron temperature, $T_e$ as a function of…

太阳与恒星天体物理 · 物理学 2017-09-13 C. E. Alissandrakis , S. Patsourakos , A. Nindos , T. S. Bastian