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We investigate the intensity and polarization of reflected light from planetary atmospheres. We present a large grid of Monte Carlo simulations for planets with Rayleigh scattering atmospheres. We discuss the disk-integrated polarization…

Earth and Planetary Astrophysics · Physics 2009-09-30 Esther Buenzli , Hans Martin Schmid

The Hanle effect has been proposed as a new diagnostic of circumstellar magnetic fields for early-type stars, for which it is sensitive to field strengths in the 1-300 G range. In this paper we compute the polarized P-Cygni line profiles…

Astrophysics · Physics 2009-11-10 R. Ignace , K. H. Nordsieck , J. P. Cassinelli

Polarization that is produced by coherent scattering can be modified by magnetic fields via the Hanle effect. According to standard theory the Hanle effect should only be operating in the Doppler core of spectral lines but not in the wings.…

Solar and Stellar Astrophysics · Physics 2011-02-11 M. Sampoorna , J. O. Stenflo , K. N. Nagendra , M. Bianda , R. Ramelli , L. S. Anusha

One of the greatest challenges in solar and stellar physics in coming years will be to observe the Second Solar Spectrum with a spatial resolution significantly better than 1 arcsec. This type of scattering polarization observations would…

Astrophysics · Physics 2009-11-13 Javier Trujillo Bueno , Nataliya Shchukina

Here we formulate and solve the 3D radiative transfer problem of the polarization of the solar continuous radiation. Our approach takes into account not only the anisotropy of the continuum radiation, but also the symmetry-breaking effects…

Astrophysics · Physics 2011-02-11 J. Trujillo Bueno , N. Shchukina

The linear polarization produced by scattering processes in the hydrogen Lyman alpha line of the solar disk radiation is a key observable for probing the chromosphere-corona transition region (TR) and the underlying chromospheric plasma.…

Solar and Stellar Astrophysics · Physics 2019-08-14 Ernest Alsina Ballester , Luca Belluzzi , Javier Trujillo Bueno

On 3rd September 2015, the Chromospheric Lyman-Alpha SpectroPolarimeter (CLASP) successfully measured the linear polarization produced by scattering processes in the hydrogen Lyman-$\alpha$ line of the solar disk radiation, revealing…

Scattering polarization signals in the Sr I 4607 \AA\ spectral line are among the strongest originating from the solar photosphere, offering a powerful diagnostic of tangled magnetic fields in the 3--300 G range via the Hanle effect.…

Recent theoretical investigations have pointed out that the cores of the Ly-alpha lines of H I and He II should show measurable scattering polarization signals when observing the solar disk, and that the magnetic sensitivity, through the…

Solar and Stellar Astrophysics · Physics 2015-06-05 Luca Belluzzi , Javier Trujillo Bueno , Jiri Stepan

Theoretical investigations predicted that high spatio-temporal resolution observations in the Sr I 4607 A line must show a conspicuous scattering polarization pattern at the solar disk-center, which encodes information on the unresolved…

Solar and Stellar Astrophysics · Physics 2021-04-21 T. del Pino Alemán , J. Trujillo Bueno

Our understanding of coronal phenomena, such as coronal plasma thermodynamics, faces a major handicap caused by missing coronal magnetic field measurements. Several lines in the UV wavelength range present suitable sensitivity to determine…

Astrophysics · Physics 2008-01-16 N. -E. Raouafi , S. K. Solanki , T. Wiegelmann

Linearly polarized emission is described, in general, in terms of the Stokes parameters $Q$ and $U$, from which the polarization intensity and polarization angle can be determined. Although the polarization intensity and polarization angle…

Astrophysics of Galaxies · Physics 2018-01-31 C. A. Herron , B. M. Gaensler , G. F. Lewis , N. M. McClure-Griffiths

One of the key research problems in stellar physics is to decipher the small-scale magnetic activity of the quiet solar atmosphere. Recent magneto-convection simulations that account for small-scale dynamo action have provided…

Solar and Stellar Astrophysics · Physics 2018-08-29 T. del Pino Alemán , J. Trujillo Bueno , J. Štěpán , N. Shchukina

The synchrotron radiation is commonly known to be completely linearly polarized when observed in the orbital plane of the synchrotron motion. Under actual experimental conditions, however, the degree of polarization of the synchrotron…

Atomic Physics · Physics 2018-11-09 A. Surzhykov , V. A. Yerokhin , S. Fritzsche , A. V. Volotka

Planets reflect and linearly polarize the radiation that they receive from their host stars. The emergent polarization is sensitive to aspects of the planet atmosphere such as the gas composition and the occurrence of condensates and their…

Earth and Planetary Astrophysics · Physics 2018-02-28 Antonio García Muñoz

For about a decade, spectro-polarimetry of HeI 10830 has been applied to the magnetic diagnostics of the solar chromosphere. This resonance line is very versatile, as it is visible both on disk and in off-limb structures, and it has a good…

Astrophysics · Physics 2011-02-11 R. Casini , R. Manso Sainz , B. C. Low

In this paper I will discuss new magnetic field diagnostics and instrumentation for an area of astrophysics where magnetic field observations have been difficult - circumstellar material. Such diagnostics would be particularly relevant to…

Astrophysics · Physics 2007-05-23 K. H. Nordsieck

Disk polarization at (sub)millimeter wavelengths is being revolutionized by ALMA observationally, but its origin remains uncertain. Dust scattering was recently recognized as a potential contributor to polarization, although its basic…

Solar and Stellar Astrophysics · Physics 2017-11-08 Haifeng Yang , Zhi-Yun Li , Leslie W. Looney , Josep M. Girart , Ian W. Stephens

Interference between magnetic substates of the hyperfine structure states belonging to different fine structure states of the same term influences the polarization for some of the diagnostically important lines of the Sun's spectrum, like…

Solar and Stellar Astrophysics · Physics 2015-12-25 K. Sowmya , K. N. Nagendra , M. Sampoorna , J. O. Stenflo

A technique based on speckle contrast measurement is proposed and demonstrated to track the polarization rotation of an optical beam behind a scattering layer. It is shown that with the help of a reference speckle pattern with a known…

Optics · Physics 2018-12-03 Abhijit Roy , Rakesh Kumar Singh , Maruthi M. Brundavanam