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Related papers: Pervasive Linear Polarization Signals in the Quiet…

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The Hanle depolarization signals of Sr 4607 A have been used to estimate the unsigned magnetic flux and magnetic energy existing in the quiet Sun photosphere. However, the Sr 4607 A Hanle signals are not sensitive to the unsigned flux and…

Astrophysics · Physics 2009-11-11 J. Sanchez Almeida

The Mg I 12.32 {\mu}m line is highly sensitive to magnetic fields due to its long wavelength, making it a promising tool for precise solar-magnetic-field measurements. The formation of this line is significantly influenced by nonlocal…

Solar and Stellar Astrophysics · Physics 2025-09-24 Yuchuan Wu , Wenxian Li , Xianyong Bai , Feng Chen , Hao Li , Yuanyong Deng

A few years before the Hinode space telescope was launched, an investigation based on the Hanle effect in atomic and molecular lines indicated that the bulk of the quiet solar photosphere is significantly magnetized, due to the ubiquitous…

Solar and Stellar Astrophysics · Physics 2015-06-12 Nataliya Shchukina , Javier Trujillo Bueno

Context: The presence of a turbulent magnetic field in the quiet Sun has been unveiled observationally using different techniques. The magnetic field is quasi-isotropic and has field strengths weaker than 100G. It is pervasive and may host…

Solar and Stellar Astrophysics · Physics 2016-11-26 A. López Ariste , A. Sainz Dalda

We use Hinode/SOT Ca II H-line and blue continuum broadband observations to study the presence and power of high frequency acoustic waves at high spatial resolution. We find that there is no dominant power at small spatial scales; the…

A new three-dimensional model of the solar photosphere is presented in this paper and made publicly available to the community. This model has the peculiarity that it has been obtained by inverting spectro-polarimetric observations, rather…

Solar and Stellar Astrophysics · Physics 2015-05-27 H. Socas-Navarro

A large set of high precision full-Stokes spectropolarimetric observations of the He-D3 line in spicules has been recorded with the ZIMPOL polarimeter at the Gregory-Coude Telescope in Locarno. The observational technique allow us to obtain…

Solar and Stellar Astrophysics · Physics 2010-11-26 R. Ramelli , M. Bianda , L. Merenda , J. Trujillo Bueno

The second solar spectrum is the solar spectrum of Stokes parameter Q observed in linear polarization close to the solar limb. It differs significantly of the usual intensity spectrum (Stokes parameter I). The second solar spectrum contains…

Instrumentation and Methods for Astrophysics · Physics 2026-03-31 Jean-Marie Malherbe

We introduce a novel approach to estimate the spectral index, $\beta_s$, of polarised synchrotron emission, combining the moment expansion of CMB and the constrained-ILC. We reconstructed the maps of the first two synchrotron moments,…

An analysis of noise attenuation during eighty solar flares between 2013 and 2017 was carried out at frequencies 8-20 MHz using thirty-four SuperDARN radars and the EKB ISTP SB RAS radar. The attenuation was determined on the basis of noise…

The near-Earth space weather is driven by the quick release of magnetic free energy in the solar corona. Probing this extremely hot and rarified region of the extended solar atmosphere requires modeling the polarization of forbidden and…

Solar and Stellar Astrophysics · Physics 2021-11-03 Supriya Hebbur Dayananda , Javier Trujillo Bueno , Ángel de Vicente , Tanausú del Pino Alemán

We present results from simulations of the extragalactic polarized sky at 1.4 GHz. As the basis for our polarization models, we use a semi-empirical simulation of the extragalactic total intensity (Stokes I) continuum sky developed at the…

Cosmology and Nongalactic Astrophysics · Physics 2009-02-13 S. P. O'Sullivan , J. M. Stil , A. R. Taylor , R. Ricci , J. K. Grant , K. Shorten

The observation of the polarization emerging from a rotating star at different phases opens up the possibility to map the magnetic field in the stellar surface thanks to the well-known Zeeman Doppler Imaging. When the magnetic field is…

Solar and Stellar Astrophysics · Physics 2015-06-05 M. J. Martínez González , A. Asensio Ramos

In the current analysis, we use spectroscopic observations of the quiet-Sun made by IRIS instrument, and investigate wave propagation. We analyze various spectral lines formed in different atmospheric layers such as the photosphere,…

Solar and Stellar Astrophysics · Physics 2024-03-18 Kartika Sangal , A. K. Srivastava , P. Kayshap , Ding Yuan , E. Scullion

We determine the number density and area contribution of small-scale inter-granular calcium-II bright G-band structures in images of the quiet Sun as tracers of kilo-Gauss magnetic flux-concentrations. In a 149" x 117" G-band image of the…

Solar and Stellar Astrophysics · Physics 2012-10-23 Burkart Bovelet , Eberhard Wiehr

We discuss spectropolarimetric measurements of photospheric (Fe I 630.25 nm) and chromospheric (Ca II 854.21 nm) spectral lines. Our long-term goal is to diagnose properties of the magnetic field near the base of the corona. We compare…

Solar and Stellar Astrophysics · Physics 2015-05-14 P. G. Judge , A. Tritschler , H. Uitenbroek , G. Cauzzi , K. Reardon , A. de Wijn

Radiative transfer investigations of the solar Mg II h and k resonance lines around 280~nm showed that, while their circular polarization (Stokes V) signals arise from the Zeeman effect, the linear polarization profiles (Stokes Q and U) are…

The Sun is an active star that often produces numerous bursts of electromagnetic radiation at radio wavelengths. Low frequency radio bursts have recently been brought back to light with the advancement of novel radio interferometers.…

Based on the Meso-Structured Magnetic Atmosphere (MESMA) approximation, recently introduced by Carroll & Kopf (2007), we present first results of an inversion of spectropolarimetric observations obtained from solar internetwork regions. To…

Astrophysics · Physics 2007-05-23 T. A. Carroll

Spectropolarimetric inversions are routinely used in the field of Solar Physics for the extraction of physical information from observations. The application to two-dimensional fields of view often requires the use of supercomputers with…

Solar and Stellar Astrophysics · Physics 2019-06-26 A. Asensio Ramos , C. Diaz Baso
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