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Related papers: The Low-Frequency Solar Corona in Circular Polariz…

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Modern radio telescopes are extremely sensitive to plasma on the line of sight from a radio source to the antenna. Plasmas in the corona and solar wind produce measurable changes in the radio wave amplitude and phase, and the phase…

Astrophysics · Physics 2009-11-13 Steven R. Spangler , Catherine A. Whiting

This study aims to investigate the ambiguous source and the underlying physical processes of the solar type III radio bursts that occurred on April 3, 2019, through the utilization of multiwavelength observations from the LOFAR radio…

Solar and Stellar Astrophysics · Physics 2023-12-20 Mohamed Nedal , Kamen Kozarev , Peijin Zhang , Pietro Zucca

Regular magnetic field structures can be derived from the Faraday rotation measures (RM) of polarized background sources observable at 1.4 GHz with the SKA. At lower frequencies ($<250$ MHz) polarimetry of radio sources with the Low…

Cosmology and Nongalactic Astrophysics · Physics 2009-04-20 Tigran G. Arshakian , Rainer Beck

Polarization profiles are presented for 20 millisecond pulsars that are being observed as part of the Parkes Pulsar Timing Array project. The observations used the Parkes multibeam receiver with a central frequency of 1369 MHz and the…

Knowledge of the electron density distribution in the solar corona put constraints on the magnetic field configurations for coronal modeling and on initial conditions for solar wind modeling. We work with polarized SOHO/LASCO-C2 images from…

Solar and Stellar Astrophysics · Physics 2015-12-15 Judith de Patoul , Claire Foullon , Pete Riley

A ubiquitous presence of weak energy releases is one of the most promising hypotheses to explain coronal heating, referred to as the nanoflare hypothesis. The accelerated electrons associated with such weak heating events are also expected…

Solar and Stellar Astrophysics · Physics 2022-10-12 Rohit Sharma , Divya Oberoi , Marina Battaglia , Sam Krucker

We have studied the implications of high sensitivity polarization measurements of objects from the WMAP point source catalogue made using the VLA at 8.4, 22 and 43 GHz. The fractional polarization of sources is almost independent of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 R. A. Battye , I. W. A. Browne , M. W. Peel , N. J. Jackson , C. Dickinson

Solar radio bursts can provide important insights into the underlying physical mechanisms that drive the small and large-scale eruptions on the Sun. Since metric radio observations can give us direct observational access to the inner and…

Solar and Stellar Astrophysics · Physics 2025-07-09 A. Kumari , D. E. Morosan , V. Mugundhan , P. Zhang , J. Magdalenic , P. Zucca , E. K. J. Kilpua , F. Daei

We report on polarimetric observations of 100 pulsars centered on 774 MHz, made using the Green Bank Telescope, presenting their polarization profiles and polarized flux densities and comparing them with previous observations when possible.…

Solar and Stellar Astrophysics · Physics 2009-03-25 J. L. Han , P. B. Demorest , W. van Straten , A. G. Lyne

The wide adoption of low-frequency radio interferometers as a tool for deeper and higher resolution astronomical observations has revolutionised radio astronomy. Despite their construction from static, relatively simple dipoles, the sheer…

Instrumentation and Methods for Astrophysics · Physics 2021-02-02 A. Chokshi , J. L. B. Line , N. Barry , D. Ung , D. Kenney , A. McPhail , A. Williams , R. L. Webster

The Murchison Widefield Array (MWA) is a low-frequency aperture array capable of high-time and frequency resolution astronomy applications such as pulsar studies. The large field-of-view of the MWA (hundreds of square degrees) can also be…

Instrumentation and Methods for Astrophysics · Physics 2022-05-18 N. A. Swainston , N. D. R. Bhat , I. S. Morrison , S. J. McSweeney , S. M. Ord , S. E. Tremblay , M. Sokolowski

Solar radio type III bursts are believed to be the most sensitive signature of near-relativistic electron beam propagation in the corona. A solar radio type IIIb-III pair burst with fine frequency structures, observed by the Low Frequency…

Solar and Stellar Astrophysics · Physics 2018-04-11 Xingyao Chen , Eduard P. Kontar , Sijie Yu , Yihua Yan , Jing Huang , Baolin Tan

We describe the parameters of a low-frequency all-sky survey of compact radio sources using Interplanetary Scintillation (IPS), undertaken with the Murchison Widefield Array (MWA). While this survey gives important complementary information…

Astrophysics of Galaxies · Physics 2019-02-08 J. S. Morgan , J-P. Macquart , R. Chhetri , R. D. Ekers , S. J. Tingay , E. M. Sadler

Spectropolarimetric results of Fraunhofer lines between 516.3nm and 532.6nm are presented in local upper solar chromosphere, transition zone and inner corona below a height of about 0.04 solar radius above the solar limb. The data were…

Solar and Stellar Astrophysics · Physics 2024-03-26 Z. Q. Qu , L. Chang , G. T. Dun , X. M. Cheng , C. Fang , Z. Xu , D. Yuan , L. H. Deng , X. Y. Zhang

Coronal mass ejections (CMEs) are large-scale eruptions of plasma from the Sun that play an important role in space weather. Faraday rotation (FR) is the rotation of the plane of polarization that results when a linearly polarized signal…

Solar and Stellar Astrophysics · Physics 2017-04-12 Jason E. Kooi , Patrick D. Fischer , Jacob J. Buffo , Steven R. Spangler

In this study we combine the multiwavelength ultraviolet -- optical (Solar Dynamics Observatory, SDO) and radio (Nobeyama Radioheliograph, NoRH) observations to get further insight into space-frequency distribution of oscillations at…

Solar and Stellar Astrophysics · Physics 2015-05-13 D. Y. Kolobov , N. I. Kobanov , A. A. Chelpanov , A. A. Kochanov , S. A. Anfinogentov , S. A. Chupin , I. I. Myshyakov , V. E. Tomin

We have measured the root-mean-square (RMS) amplitude of intensity fluctuations, $\Delta I$, in plume and interplume regions of a polar coronal hole. These intensity fluctuations correspond to density fluctuations. Using data from the…

Solar and Stellar Astrophysics · Physics 2018-06-27 Michael Hahn , Elke D'Huys , Daniel Wolf Savin

We seek to reconcile observations of small source sizes in the solar corona at 327 MHz with predictions of scattering models that incorporate refractive index effects, inner scale effects and a spherically diverging wavefront. We use an…

Solar and Stellar Astrophysics · Physics 2015-05-20 Prasad Subramanian , Iver Cairns