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Related papers: Linear Polarization Features in the Quiet-Sun Phot…

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The LOFAR Two-metre Sky Survey (LoTSS) is an ongoing sensitive, high-resolution 120-168MHz survey of the entire northern sky for which observations are now 20% complete. We present our first full-quality public data release. For this data…

Astrophysics of Galaxies · Physics 2018-11-21 T. W. Shimwell , C. Tasse , M. J. Hardcastle , A. P. Mechev , W. L. Williams , P. N. Best , H. J. A. Röttgering , J. R. Callingham , T. J. Dijkema , F. de Gasperin , D. N. Hoang , B. Hugo , M. Mirmont , J. B. R. Oonk , I. Prandoni , D. Rafferty , J. Sabater , O. Smirnov , R. J. van Weeren , G. J. White , M. Atemkeng , L. Bester , E. Bonnassieux , M. Brüggen , G. Brunetti , K. T. Chyży , R. Cochrane , J. E. Conway , J. H. Croston , A. Danezi , K. Duncan , M. Haverkorn , G. H. Heald , M. Iacobelli , H. T. Intema , N. Jackson , M. Jamrozy , M. J. Jarvis , R. Lakhoo , M. Mevius , G. K. Miley , L. Morabito , R. Morganti , D. Nisbet , E. Orrú , S. Perkins , R. F. Pizzo , C. Schrijvers , D. J. B. Smith , R. Vermeulen , M. W. Wise , L. Alegre , D. J. Bacon , I. M. van Bemmel , R. J. Beswick , A. Bonafede , A. Botteon , S. Bourke , M. Brienza , G. Calistro Rivera , R. Cassano , A. O. Clarke , C. J. Conselice , R. J. Dettmar , A. Drabent , C. Dumba , K. L. Emig , T. A. Enßlin , C. Ferrari , M. A. Garrett , R. T. Génova-Santos , A. Goyal , G. Gürkan , C. Hale , J. J. Harwood , V. Heesen , M. Hoeft , C. Horellou , C. Jackson , G. Kokotanekov , R. Kondapally , M. Kunert-Bajraszewska , V. Mahatma , E. K. Mahony , S. Mandal , J. P. McKean , A. Merloni , B. Mingo , A. Miskolczi , S. Mooney , B. Nikiel-Wroczyński , S. P. O'Sullivan , J. Quinn , W. Reich , C. Roskowiński , A. Rowlinson , F. Savini , A. Saxena , D. J. Schwarz , A. Shulevski , S. S. Sridhar , H. R. Stacey , S. Urquhart , M. H. D. van der Wiel , E. Varenius , B. Webster , A. Wilber

We present the results of the first survey and monitoring study of the linear polarisation properties of compact, flat-spectrum radio sources at millimetre/submillimetre wavelengths and discuss the implications of the inferred magnetic…

Astrophysics · Physics 2015-06-24 R. Nartallo , W. K. Gear , A. G. Murray , E. I Robson , J. H. Hough

Context. The Sun is an active source of radio emission that is often associated with energetic phenomena ranging from nanoflares to coronal mass ejections (CMEs). At low radio frequencies (<100 MHz), numerous millisecond duration radio…

We present spectropolarimetric imaging observations of the solar corona at low frequencies (80 - 240 MHz) using the Murchison Widefield Array (MWA). These images are the first of their kind, and we introduce an algorithm to mitigate an…

Solar and Stellar Astrophysics · Physics 2019-09-04 Patrick I. McCauley , Iver H. Cairns , Stephen M. White , Surajit Mondal , Emil Lenc , John Morgan , Divya Oberoi

Blazars are astrophysical sources whose emission is dominated by non-thermal processes, typically interpreted as synchrotron and inverse Compton emission. Although the general picture is rather robust and consistent with observations, many…

The morphology of circular polarisation profiles from solar spectropolarimetric observations encode information about the magnetic field strength, inclination, and line-of-sight velocity gradients. Previous studies used manual methods or…

Solar and Stellar Astrophysics · Physics 2025-05-21 Ryan James Campbell , Mihalis Mathioudakis , Carlos Quintero Noda , Peter Keys , David Orozco Suárez

We present a study of the linear polarization properties of radio sources within the 10 deg$^2$ Wide Chandra Deep Field South (W-CDFS) in S-band (2-4 GHz). Our W-CDFS image has an angular resolution of 15 arcsec and a 1$\sigma$ RMS in…

Physical systems with co-existence and interplay of processes featuring distinct spatio-temporal scales are found in various research areas ranging from studies of brain activity to astrophysics. Complexity of such systems makes their…

To study the structure of spatially unresolved features of the solar photosphere, we calculated the Stokes profiles of seven photospheric iron lines using two-dimensional nonstationary MHD models of solar granulation for various amounts of…

Solar and Stellar Astrophysics · Physics 2012-11-13 I. N. Atroshchenko , V. A. Sheminova

We present the first section of a radio continuum and polarization survey at medium Galactic latitudes carried out with the Effelsberg 100-m telescope at 1.4 GHz. Four large fields have been observed, which all together cover an area of…

Astrophysics · Physics 2009-10-31 B. Uyaniker , E. Fuerst , W. Reich , P. Reich , R. Wielebinski

The evolution of small magnetic features in quiet regions of the Sun provides a unique window to probing solar magneto-convection. Here we analyze small scale magnetic features in the quiet Sun, using the high resolution, seeing-free…

Solar and Stellar Astrophysics · Physics 2017-02-01 L. S. Anusha , Sami K. Solanki , Johann Hirzberger , Alex Feller

High levels of horizontal magnetic flux have been reported in the quiet-Sun internetwork, often based on Stokes profile inversions. Here we introduce a new method for deducing the inclination of magnetic elements and use it to test magnetic…

Solar and Stellar Astrophysics · Physics 2014-10-01 S. Jafarzadeh , S. K. Solanki , A. Lagg , L. R. Bellot Rubio , M. van Noort , A. Feller , S. Danilovic

Aims. We aim at studying the near infrared linear polarization signal of rapidly rotating ultracool dwarfs with spectral types ranging from M7 through T2 and projected rotational velocities vsini >= 30 km s^{-1}. All these dwarfs are…

Solar and Stellar Astrophysics · Physics 2015-06-16 Paulo Alberto Miles-Páez , María Rosa Zapatero Osorio , Enric Pallé , Karla Peña Ramírez

Aims: The ``bright'' High Frequency Peakers (HFPs) sample is a mixture of blazars and intrinsically small and young radio sources. We investigate the polarimetric characteristics of 45 High Frequency Peakers, from the ``bright'' HFP sample,…

Astrophysics · Physics 2009-11-13 M. Orienti , D. Dallacasa

The distribution of ultra-narrow linewidth laser radiation is an integral part of many challenging metrological applications. Changes in the optical pathlength induced by environmental disturbances compromise the stability and accuracy of…

Instrumentation and Detectors · Physics 2018-07-31 Benjamin Rauf , Maria Carmen Velez Lopez , Pierre Thoumany , Marco Pizzocaro , Davide Calonico

The magnetic topology of the solar photosphere in its quietest regions is hidden by the difficulties to disentangle magnetic flux through the resolution element from the field strength of unresolved structures. The observation of spectral…

Astrophysics · Physics 2015-05-13 J. C. Ramirez Velez , A. Lopez Ariste , M. Semel

A quiet Sun magnetic flux cancelation event at the disk centre was recorded using the Integral Field Unit (IFU) mounted on the GREGOR Infrared Spectrograph (GRIS). GRIS sampled the event in the photospheric Si I 10827 {\AA} spectral line.…

Solar and Stellar Astrophysics · Physics 2020-02-26 Anjali. J. Kaithakkal , J. M. Borrero , C. E. Fischer , C. Dominguez-Tagle , M. Collados

Three different maps of the quiet Sun, observed with the Advanced Stokes Polarimeter (ASP) and the Diffraction-Limited Stokes Polarimeter (DLSP), show evidence of strong ($\simeq$1700 G) and weak ($<$500 G) fields coexisting within the…

Astrophysics · Physics 2008-11-26 H. Socas-Navarro , B. W. Lites

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

With the forthcoming release of high precision polarization measurements, such as from the Planck satellite, the metrology of polarization needs to improve. In particular, it is crucial to take into account full knowledge of the noise…

Instrumentation and Methods for Astrophysics · Physics 2015-02-11 L. Montier , S. Plaszczynski , F. Levrier , M. Tristram , D. Alina , I. Ristorcelli , J. -P. Bernard