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相关论文: Description of anomalous Zeeman patterns in stella…

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Zeeman-Doppler imaging (ZDI) is used to study the surface magnetic field topology of stars, based on high-resolution spectropolarimetric time series observations. Multiple ZDI inversions have been conducted for the early B-type star tau…

太阳与恒星天体物理 · 物理学 2025-07-02 Jennifer Rosina Andersson , Oleg Kochukhov , Zheng Zhao , Jens Sjölund

Magnetic activity and rotation are known to be intimately linked for low-mass stars. Understanding rotation evolution over the stellar lifetime is therefore an important goal within stellar astrophysics. In recent years, there has been…

The distortion from massive MIMO (multiple-input--multiple-output) base stations with nonlinear amplifiers is studied and its radiation pattern is derived. The distortion is analyzed both in-band and out-of-band. By using an orthogonal…

信息论 · 计算机科学 2018-05-04 Christopher Mollén , Ulf Gustavsson , Thomas Eriksson , Erik G. Larsson

Recent comparisons of magnetic field directions derived from maser Zeeman splitting with those derived from continuum source rotation measures have prompted new analysis of the propagation of the Zeeman split components, and the inferred…

星系天体物理 · 物理学 2015-06-19 J. A. Green , M. D. Gray , T. Robishaw , J. L. Caswell , N. M. McClure-Griffiths

Context. Recent high angular resolution polarimetric continuum observations of circumstellar disks provide new insights into their magnetic field. However, direct constraints are limited to the plane of sky component of the magnetic field.…

太阳与恒星天体物理 · 物理学 2017-11-22 R. Brauer , S. Wolf , M. Flock

Context. Observations of Zeeman split spectral lines represent an important approach to derive the structure and strength of magnetic fields in molecular clouds. In contrast to the uncertainty of the spectral line observation itself, the…

星系天体物理 · 物理学 2017-05-10 R. Brauer , S. Wolf , S. Reissl , F. Ober

2008 marks the 100th anniversary of the discovery of astrophysical magnetic fields, when George Ellery Hale recorded the Zeeman splitting of spectral lines in sunspots. With the introduction of Babcock's photoelectric magnetograph it soon…

太阳与恒星天体物理 · 物理学 2015-05-13 J. O. Stenflo

Observational astrophysics started when spectroscopy could be applied to astronomy. Similarly, observational work on stellar magnetic fields became possible with the application of spectro-polarimetry. In recent decades there have been…

太阳与恒星天体物理 · 物理学 2015-06-17 J. O. Stenflo

An extremely weak circularly-polarized signature was recently discovered in spectral lines of the chemically peculiar Am star Sirius A (Petit et al. 2011). This signal was interpreted as a Zeeman signature related to a sub-gauss…

太阳与恒星天体物理 · 物理学 2015-08-06 Aurore Blazère , Pascal Petit , François Lignières , Michel Aurière , Torsten Böhm , Gregg Wade

Full disk vector magnetic fields are used widely for developing better understanding of large-scale structure, morphology, and patterns of the solar magnetic field. The data are also important for modeling various solar phenomena. However,…

太阳与恒星天体物理 · 物理学 2021-01-19 Alexei A. Pevtsov , Yang Liu , Ilpo Virtanen , Luca Bertello , Kalevi Mursula , K. D. Leka , Anna L. H. Hughes

Direct measurements of the stellar magnetic fields are based on the splitting of spectral lines into polarized Zeeman components. With few exceptions, Zeeman signatures are hidden in data noise and a number of methods have been developed to…

Low-mass stars are known to have magnetic fields that are believed to be of dynamo origin. Two complementary techniques are principally used to characterise them. Zeeman-Doppler imaging (ZDI) can determine the geometry of the large-scale…

A multi-line Bayesian analysis of the Zeeman broadening in the solar atmosphere is presented. A hierarchical probabilistic model, based on the simple but realistic Milne-Eddington approximation to the solution of the radiative transfer…

太阳与恒星天体物理 · 物理学 2015-06-18 A. Asensio Ramos

The strengths of magnetic fields in interstellar gas clouds are obtained through observations of the circular polarization of spectral line radiation. Irregularities in this magnetic field may be present due to turbulence, waves or perhaps…

天体物理学 · 物理学 2009-10-31 W. D. Watson , D. S. Wiebe , R. M. Crutcher

In this paper we study the feasibility of inferring the magnetic field from polarized multi-line spectra using two methods: The pseudo line approach and The PCA-ZDI approach. We use multi-line techniques, meaning that all the lines of a…

太阳与恒星天体物理 · 物理学 2015-05-14 J. C. Ramirez Velez , M. Semel , M. Stift , M. J. Martinez Gonzalez , P. Petit , N. Dunstone

In this paper, the Schr{\"o}dinger equation in a magnetic field is utilized to study the effect of the magnetic field on $B$ mesons. The mass spetrum of $B$ mesons are numerically calculated for different magnetic field strengths by solving…

综合物理 · 物理学 2025-03-12 Bing-Rui Ma , Hao Chen , Cheng-Qun Pang

Observational constraints on stellar magnetic fields are essential to both stellar and planetary physics. Recent studies revealed the diversity and evolution of large-scale magnetic fields in low-mass stars. These large-scale fields only…

太阳与恒星天体物理 · 物理学 2026-03-27 Paul I. Cristofari , Steven H. Saar , Aline A. Vidotto , Stefano Bellotti

This paper reviews some of the developments that over the last 10 years have allowed us to go from deciphering the physical origin of several of the enigmatic features of the second solar spectrum to discovering unknown aspects of the Sun's…

天体物理学 · 物理学 2008-12-24 J. Trujillo Bueno

Characterization of the trap rf induced a.c. Zeeman shift is essential for achieving high accuracy in optical ion clocks. In this work, we demonstrate the experimental characterization of this shift using highly charged $\mathrm{Ca}^{14+}$.…

After a short introduction on how we get information of the magnetic fields from radio observations I discuss the results concerning the magnetic field structure in galaxies: Large-scale regular magnetic field pattern of spiral structure…

天体物理学 · 物理学 2007-05-23 M. Krause