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The physics of the solar chromosphere depends in a crucial way on its magnetic structure. However there are presently very few direct magnetic field diagnostics available for this region. Here we investigate the diagnostic potential of the…

Astrophysics · Physics 2009-11-13 M. Faurobert , M. Derouich , V. Bommier , J. Arnaud

The Zeeman pattern of MnI lines is sensitive to hyperfine structure (HFS) and, they respond to hG magnetic field strengths differently from the lines used in solar magnetometry. This peculiarity has been employed to measure magnetic field…

Astrophysics · Physics 2009-11-13 J. Sanchez Almeida , B. Viticchie , E. Landi Degl'Innocenti , F. Berrilli

We will show that isotropic collisions of electrons and protons with neutral hydrogen can lead to creation of net orientation of the atomic levels in the presence of a magnetic field. Consequently, the emitted Stokes-V profile of the…

Astrophysics · Physics 2008-12-01 Jiri Stepan , Sylvie Sahal-Brechot

Polarized magnetic dipole (M1) emission lines provide important diagnostics for the magnetic field dominating the evolution of the solar corona. This paper advances a multi-line technique using specific combinations of M1 lines to infer the…

Solar and Stellar Astrophysics · Physics 2020-02-12 Gabriel I. Dima , Thomas A. Schad

A novel diagnostic of cosmic-ray modified shocks by polarimetry of H $\alpha$ emissions is suggested. In a cosmic-ray modified shock, the pressure of cosmic rays is sufficiently high compared to the upstream ram pressure to force the…

High Energy Astrophysical Phenomena · Physics 2019-09-25 Jiro Shimoda , J. Martin Laming

Some massive stars possess strong magnetic fields that confine plasma in the circumstellar environment. These \textit{magnetospheres} have been studied spectroscopically, photometrically and, more recently, interferometrically. Here we…

Solar and Stellar Astrophysics · Physics 2015-06-15 Alex C. Carciofi , Daniel M. Faes , Richard H. D. Townsend , Jon E Bjorkman

The near-star environment around obscured stars is very dynamic. Many classes of stars show evidence for winds, disks, inflows and outflows with many phenomena occurring simultaneously. These processes are involved in stellar evolution,…

Astrophysics · Physics 2008-09-22 D. M. Harrington , J. R. Kuhn

We take a broad look at the problem of identifying the magnetic solar causes of space weather. With the lackluster performance of extrapolations based upon magnetic field measurements in the photosphere, we identify a region in the near UV…

We present high resolution (R ~ 60,000) circular spectropolarimetry of the classical T Tauri star TW Hydrae. We analyze 12 photospheric absorption lines and measure the net longitudinal magnetic field for 6 consecutive nights. While no net…

Astrophysics · Physics 2008-11-26 H. Yang , C. M. Johns-Krull , J. A. Valenti

We present a joint analysis of HI absorption Zeeman measurements and the morphology of filamentary HI emission to investigate the three-dimensional structure of the magnetic field in the diffuse neutral interstellar medium (ISM). Our…

Astrophysics of Galaxies · Physics 2025-08-28 Marta Nowotka , Susan E. Clark , Blakesley Burkhart , Laura Fissel , Tao-Chung Ching , Timothy Robishaw , Carl Heiles

The measurement of the linear polarization is one of the hot topics of High Energy Astrophysics. Gas detectors based on photoelectric effect have paved the way for the design of sensitive instruments and mission proposals based on them have…

Instrumentation and Methods for Astrophysics · Physics 2015-06-18 Fabio Muleri

We report Stokes vector observations of solar spicules and a prominence in the He I 1083 nm multiplet carried out with the Tenerife Infrared Polarimeter. The observations show linear polarization profiles that are produced by scattering…

Solar and Stellar Astrophysics · Physics 2015-06-11 M. J. Martínez González , A. Asensio Ramos , R. Manso Sainz , C. Beck , L. Belluzzi

Rigorous implementation of the effects of collisions in modeling the formation of the polarized solar lines is of utmost importance in order to realistically analyze the available, highly sensitive solar spectropolarimetric observations.…

Solar and Stellar Astrophysics · Physics 2024-02-02 Moncef Derouich , Saleh Qutub

Calculations are performed for the circular polarization of maser radiation from a turbulent, Keplerian disk that is intended to represent the sub-parsec disk at the nucleus of the galaxy NGC4258. The polarization in the calculations is a…

Astrophysics · Physics 2009-11-06 W. D. Watson , D. S. Wiebe

We study the anomalous electromagnetic scattering in the homogenization regime, by a subwavelength thin layer of periodically distributed plasmonic nanoparticles on a perfect conducting plane. By using layer potential techniques, we derive…

Analysis of PDEs · Mathematics 2019-07-17 Habib Ammari , Bowen Li , Jun Zou

We demonstrate that the atomic alignment of the hyperfine-structure components of the ground level S$_{1/2}$ of Na {\sc i} and of the upper level P$_{1/2}$ of the D$_1$ line are practically negligible for magnetic strengths $B>10 \rm G$,…

This study describes both experimentally and theoretically an important hitherto undiscovered feature of the scattering of micron_sized spherical objects when illuminated with highly focused circularly polarized light. This is a regime of…

A flare kernel associated with a C4 class flare was observed in a spectral window including the He I triplet 10830 A and Si I 10827 A with a spectropolarimeter on the Domeless Solar Telescope at Hida Observatory on August 9th, 2015.…

Solar and Stellar Astrophysics · Physics 2018-10-17 Tetsu Anan , Takurou Yoneya , Kiyoshi Ichimoto , Satoru Ueno , Daikou Shiota , Satoshi Nozawa , Shinsuke Takasao , Tomoko Kawate

Quantum interference effects together with partial frequency redistribution (PFR) in line scattering produce subtle signatures in the so called Second Solar Spectrum (the linearly polarized spectrum of the Sun). These signatures are…

Solar and Stellar Astrophysics · Physics 2019-10-25 M. Sampoorna , K. N. Nagendra , K. Sowmya , J. O. Stenflo , L. S. Anusha

A theoretical investigation is carried out to understand the basic features of nonlinear propagation of heavy ion-acoustic (HIA) waves subjected to an external magnetic field in an electron-positron-ion (EPI) plasma which consists of cold…

Plasma Physics · Physics 2017-11-21 M. Sarker , B. Hosen , M. G. Shah , M. R. Hossen , A. A. Mamun
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